:root{
 --paper:#fffdf7;--cream:#f6efe1;--cream-2:#efe2cc;--ink:#24322b;--muted:#66756d;
 --green:#416957;--green-dark:#294a3c;--green-soft:#e3eee7;--orange:#d4864b;--rose:#b8655c;
 --line:#d9d2c5;--shadow:0 18px 48px rgba(68,55,37,.12);--radius:24px;
 font-family:"Microsoft YaHei UI","Microsoft YaHei","PingFang SC","Noto Sans CJK SC",system-ui,-apple-system,"Segoe UI",sans-serif;color:var(--ink);
}
*{box-sizing:border-box}html,body{margin:0;min-height:100%;background:var(--cream)}
body{min-height:100vh;background:
 radial-gradient(circle at 8% 10%,rgba(255,255,255,.9),transparent 28rem),
 radial-gradient(circle at 92% 86%,rgba(227,238,231,.9),transparent 30rem),
 var(--cream)}
button,input,select,textarea{font:inherit}button{cursor:pointer}
button:disabled{cursor:not-allowed;opacity:.5}
a{color:inherit}.hidden,[hidden]{display:none!important}
#app{min-height:100vh}
.boot-card,.auth-card,.ended-card{width:min(720px,calc(100% - 32px));margin:clamp(60px,12vh,130px) auto;background:var(--paper);border:1px solid var(--line);border-radius:32px;padding:clamp(28px,5vw,52px);box-shadow:var(--shadow)}
.brand-mark{width:54px;height:54px;border-radius:18px;background:var(--green);color:#fff;display:grid;place-items:center;font:700 28px/1 Georgia,serif;box-shadow:0 8px 20px rgba(65,105,87,.25)}
.eyebrow{letter-spacing:.14em;font-size:12px;font-weight:800;color:var(--green);text-transform:uppercase;margin:18px 0 8px}
h1,h2,h3,p{margin-top:0}h1{font-size:clamp(28px,4vw,48px);line-height:1.15}h2{font-size:clamp(22px,2.4vw,32px)}h3{font-size:19px}
.muted{color:var(--muted)}.tiny{font-size:12px}.strong{font-weight:800}.math{font-family:"Cambria Math","Times New Roman",serif;font-style:italic;letter-spacing:.02em}
.btn,button{border:1px solid var(--line);background:#fff;color:var(--ink);border-radius:14px;padding:11px 16px;font-weight:700;transition:.16s ease}
button:hover,.btn:hover{transform:translateY(-1px);box-shadow:0 7px 18px rgba(58,52,42,.08)}
button.primary,.btn.primary{background:var(--green);color:#fff;border-color:var(--green)}
button.warm{background:#fff4e7;border-color:#eac7a5;color:#8c552f}
button.danger{background:#fff0ee;border-color:#e2b6b1;color:#8d3e38}
button.ghost{background:transparent}.row{display:flex;align-items:center;gap:10px;flex-wrap:wrap}
.field{display:grid;gap:7px}.field>span{font-weight:700;font-size:14px}
input,select,textarea{width:100%;border:1px solid var(--line);border-radius:13px;background:#fff;padding:12px 13px;color:var(--ink);outline:none}
input:focus,select:focus,textarea:focus{border-color:var(--green);box-shadow:0 0 0 3px rgba(65,105,87,.12)}
textarea{min-height:88px;resize:vertical}
.auth-grid{display:grid;grid-template-columns:1fr 1fr;gap:14px}.auth-grid .wide{grid-column:1/-1}
.auth-actions{display:flex;align-items:center;gap:12px;margin-top:20px}
.notice{border-radius:16px;padding:13px 16px;background:var(--green-soft);color:var(--green-dark)}
.warning{background:#fff1e8;color:#85502e}
#classroom-toast{position:fixed;z-index:100;left:50%;bottom:28px;transform:translate(-50%,24px);opacity:0;pointer-events:none;background:#20372d;color:#fff;padding:12px 18px;border-radius:999px;box-shadow:0 10px 28px rgba(0,0,0,.18);transition:.2s}
#classroom-toast.show{opacity:1;transform:translate(-50%,0)}

.teacher-shell{min-height:100vh;display:grid;grid-template-rows:auto 1fr}
.teacher-top{display:flex;align-items:center;gap:14px;padding:12px 18px;border-bottom:1px solid var(--line);background:rgba(255,253,247,.94);backdrop-filter:blur(12px);position:sticky;top:0;z-index:20}
.teacher-top .brand{font-weight:900;color:var(--green-dark);margin-right:auto}.teacher-top .session-state{padding:6px 10px;border-radius:999px;background:var(--green-soft);font-weight:800;font-size:13px}
.teacher-grid{display:grid;grid-template-columns:minmax(0,1fr) 330px;min-height:0}
.stage-screen{padding:clamp(18px,3vw,42px);min-width:0;display:flex;flex-direction:column;gap:20px}
.control-rail{border-left:1px solid var(--line);background:rgba(255,253,247,.92);padding:18px;overflow:auto;max-height:calc(100vh - 62px);position:sticky;top:62px}
.rail-section{padding:15px 0;border-bottom:1px solid var(--line)}.rail-section:last-child{border-bottom:0}
.stage-tabs{display:grid;grid-template-columns:repeat(3,1fr);gap:7px}
.stage-tab{padding:9px 7px;font-size:12px}.stage-tab.active{background:var(--green);color:#fff;border-color:var(--green)}
.lesson-head{display:flex;align-items:flex-start;justify-content:space-between;gap:20px}
.lesson-head h1{margin-bottom:7px}.lesson-number{display:inline-grid;place-items:center;width:42px;height:42px;border-radius:50%;background:var(--orange);color:#fff;font-weight:900}
.story-scene{display:grid;grid-template-columns:1fr 1fr;gap:18px;align-items:stretch}
.character-card{background:var(--paper);border:1px solid var(--line);border-radius:28px;padding:22px;box-shadow:var(--shadow);position:relative;overflow:hidden}
.character-card:after{content:"";position:absolute;width:130px;height:130px;border-radius:50%;right:-38px;bottom:-50px;background:var(--green-soft)}
.avatar{width:74px;height:74px;border-radius:50%;display:grid;place-items:center;font-size:38px;background:#f9dec9;margin-bottom:15px}.dad .avatar{background:#dce9df}
.speech{font-size:clamp(20px,2.4vw,34px);font-weight:800;line-height:1.45;position:relative;z-index:1}
.age-table{width:100%;border-collapse:separate;border-spacing:0;background:var(--paper);border:1px solid var(--line);border-radius:20px;overflow:hidden}
.age-table th,.age-table td{padding:14px 18px;text-align:center;border-bottom:1px solid var(--line);font-size:clamp(17px,1.8vw,24px)}
.age-table tr:last-child td{border-bottom:0}.age-table th{background:var(--green-soft)}
.relation-banner{padding:20px 24px;border-radius:22px;background:var(--green-dark);color:#fff;text-align:center;font-size:clamp(22px,3vw,38px);font-weight:800}
.task-card{background:var(--paper);border:1px solid var(--line);border-radius:var(--radius);padding:22px;box-shadow:var(--shadow)}
.task-card .prompt{font-size:clamp(20px,2.2vw,30px);font-weight:800;line-height:1.45}
.metric-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:12px}
.metric{background:var(--paper);border:1px solid var(--line);border-radius:18px;padding:15px}.metric b{display:block;font-size:28px;color:var(--green-dark)}
.results-grid{display:grid;grid-template-columns:1fr 1fr;gap:14px}
.result-box{background:var(--paper);border:1px solid var(--line);border-radius:20px;padding:18px;min-width:0}
.frequency{display:flex;align-items:center;gap:10px;padding:9px 0;border-bottom:1px dashed var(--line)}.frequency:last-child{border:0}
.frequency .bar{height:8px;border-radius:99px;background:var(--green);min-width:8px;flex:0 0 auto}
.expression-list{display:grid;grid-template-columns:repeat(auto-fit,minmax(210px,1fr));gap:10px}
.expression-card{border:1px solid var(--line);background:#fff;border-radius:16px;padding:13px;min-width:0}
.expression-card .formula{font:700 23px/1.4 "Cambria Math","Times New Roman",serif;word-break:break-word}
.featured{border:2px solid var(--orange);background:#fff9ef}
.join-box{display:grid;grid-template-columns:112px 1fr;gap:13px;align-items:center}
#join-qr{width:112px;height:112px;background:white;border-radius:9px;padding:6px;border:1px solid var(--line);image-rendering:pixelated}
.join-url{font-size:12px;word-break:break-all;color:var(--muted)}
.session-list{display:grid;gap:10px}.session-item{width:100%;text-align:left}.session-item.active{border-color:var(--green);background:var(--green-soft)}
.class-checks{display:grid;grid-template-columns:repeat(auto-fit,minmax(170px,1fr));gap:8px;margin:10px 0}
.check-card{display:flex;gap:8px;align-items:center;border:1px solid var(--line);border-radius:12px;padding:9px;background:#fff}.check-card input{width:auto}
body.presentation-mode .control-rail{display:none}body.presentation-mode .teacher-grid{grid-template-columns:1fr}body.presentation-mode .teacher-top .teacher-hide{display:none}
body.presentation-mode .stage-screen{padding:3vw 5vw}.presentation-toggle{white-space:nowrap}

/* Teacher dashboard: the high-frequency join action and live roster stay visually primary. */
.join-students-btn{order:-2;background:#234f3e!important;color:#fff!important;border-color:#234f3e!important;font-weight:800}
.dual-mode-toggle.active{background:#183f68;color:#fff;border-color:#183f68}
.student-status-section{order:-5}.student-status-panel{display:grid;gap:10px}.student-status-head{display:flex;justify-content:space-between;gap:12px;align-items:baseline}.student-status-head span{font-size:12px;color:var(--muted)}
.student-status-grid{display:grid;grid-template-columns:repeat(8,minmax(0,1fr));gap:5px}.student-status-cell{aspect-ratio:1;display:grid;place-items:center;border:1px solid #c7cec8;border-radius:5px;font-size:11px;font-weight:800;color:#26352f;background:#d7d9d8}.student-status-cell.uncreated{background:#fff}.student-status-cell.listening{background:#75c889}.student-status-cell.answering{background:#f4d35e}.student-status-cell.submitted{background:#ef8b43;color:#fff}
.student-status-legend{display:flex;flex-wrap:wrap;gap:5px 8px;align-items:center;font-size:11px;color:var(--muted)}.student-status-legend i{width:11px;height:11px;border-radius:3px;border:1px solid #bfc6c0;background:#d7d9d8}.student-status-legend .uncreated{background:#fff}.student-status-legend .listening{background:#75c889}.student-status-legend .answering{background:#f4d35e}.student-status-legend .submitted{background:#ef8b43}

/* One-screen teacher/student rehearsal. The lower pane keeps the student's native aspect ratio. */
.dual-student-preview{display:none}.dual-screen-mode.presentation-mode .stage-screen{display:grid;grid-template-rows:minmax(0,2fr) minmax(210px,1fr);gap:8px;align-items:stretch}.dual-screen-mode .lesson-stage{min-height:0}.dual-screen-mode .dual-student-preview{display:block!important;position:relative;overflow:hidden;border:2px solid #b9c9bf;border-radius:16px;background:#eef3ef}.dual-preview-label{position:absolute;z-index:2;left:12px;top:8px;padding:4px 9px;border-radius:999px;background:#234f3e;color:#fff;font-size:12px;font-weight:800}.dual-student-preview iframe{width:133.333%;height:133.333%;border:0;transform:scale(.75);transform-origin:0 0;background:#fff}

/* Correct 2.4 answers overlay the original board instead of replacing it. */
.meaning-connection-teacher.show-answer .meaning-columns{opacity:.42}.meaning-connection-teacher.show-answer .meaning-answer-blackboard{position:absolute;inset:22% 8% 13%;z-index:3;background:rgba(255,252,244,.94);box-shadow:0 12px 36px rgba(36,55,45,.18)}

.student-shell{min-height:100vh;display:flex;flex-direction:column}
.student-top{display:flex;align-items:center;gap:12px;padding:14px clamp(16px,4vw,36px);background:rgba(255,253,247,.94);border-bottom:1px solid var(--line)}
.student-brand{font-weight:900;color:var(--green-dark);margin-right:auto}.student-id{font-size:13px;color:var(--muted)}
.student-main{width:min(980px,100%);margin:0 auto;padding:clamp(18px,5vw,48px);flex:1;display:flex;flex-direction:column;justify-content:center}
.student-stage-tag{display:inline-flex;align-items:center;gap:8px;align-self:flex-start;background:var(--green-soft);border-radius:999px;padding:7px 12px;font-weight:800;color:var(--green-dark);margin-bottom:14px}
.student-task{background:var(--paper);border:1px solid var(--line);border-radius:30px;padding:clamp(22px,5vw,42px);box-shadow:var(--shadow)}
.student-task h1{font-size:clamp(28px,5vw,44px)}.student-task .prompt{font-size:clamp(19px,3vw,27px);line-height:1.55;font-weight:700}
.waiting{text-align:center;padding:30px 10px}.waiting .big-icon{font-size:56px;margin-bottom:12px}
.choice-grid{display:grid;gap:12px;margin:22px 0}.choice-option{display:flex;align-items:center;gap:13px;text-align:left;padding:17px 19px;border:2px solid var(--line);border-radius:18px;background:#fff;font-size:18px}.choice-option input{width:auto;accent-color:var(--green)}.choice-option:has(input:checked){border-color:var(--green);background:var(--green-soft)}
.builder{display:grid;gap:16px;margin:20px 0}.builder-row{display:grid;grid-template-columns:1fr 110px 1fr 110px;gap:10px;align-items:end}
.symbol-pick{display:grid;grid-template-columns:1fr 1fr;gap:7px}.symbol-pick input[hidden]{display:none}
.formula-preview{background:var(--green-dark);color:#fff;border-radius:20px;padding:18px;text-align:center;font:700 clamp(26px,5vw,42px)/1.2 "Cambria Math","Times New Roman",serif}
.translation{background:#fff6ea;border-radius:16px;padding:13px 16px;color:#784e2f}
.submit-row{display:flex;gap:10px;align-items:center;margin-top:20px}.submit-row button{min-height:50px;min-width:140px}
.number-entry{max-width:330px;margin:24px auto;text-align:center}.number-entry input{text-align:center;font-size:34px;font-weight:800;padding:18px}
.scenario-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(160px,1fr));gap:10px;margin:18px 0}
.scenario-card{padding:16px;border:2px solid var(--line);border-radius:18px;background:#fff;text-align:left}.scenario-card.active{border-color:var(--green);background:var(--green-soft)}.scenario-card .icon{font-size:30px;display:block;margin-bottom:8px}
.quantity-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:10px;margin:15px 0}.quantity-card{background:#fff8ee;border-radius:15px;padding:12px}.quantity-card small{display:block;color:var(--muted)}
.symbol-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:10px}
.feedback{border-radius:18px;padding:18px;margin-top:18px;font-weight:800}.feedback.correct{background:#e6f3e9;color:#285b3c}.feedback.wrong{background:#fff0ea;color:#8a4b34}
.personal-progress{margin-top:18px;color:var(--muted);font-size:13px}
.mobile-only{display:none}

@media(max-width:900px){
 .teacher-grid{grid-template-columns:1fr}.control-rail{position:static;max-height:none;border-left:0;border-top:1px solid var(--line)}
 .metric-grid{grid-template-columns:repeat(2,1fr)}.results-grid,.story-scene{grid-template-columns:1fr}
 .teacher-top{flex-wrap:wrap}.join-box{grid-template-columns:90px 1fr}#join-qr{width:90px;height:90px}
 .builder-row{grid-template-columns:1fr 90px}.builder-row>.field:nth-child(3){grid-column:1}.builder-row>.field:nth-child(4){grid-column:2}
}
@media(max-width:620px){
 :root{--radius:20px}.auth-grid{grid-template-columns:1fr}.auth-grid .wide{grid-column:auto}
 .student-main{padding:16px}.student-task{padding:22px 17px;border-radius:22px}.student-top{padding:11px 14px}
 .student-id{max-width:46vw;text-align:right}.quantity-grid,.symbol-grid{grid-template-columns:1fr}.metric-grid{grid-template-columns:1fr 1fr}
 .stage-tabs{grid-template-columns:repeat(2,1fr)}.results-grid{grid-template-columns:1fr}.lesson-head{display:block}.lesson-number{margin-bottom:10px}
 .expression-list{grid-template-columns:1fr}.mobile-only{display:block}
}
@media(orientation:landscape) and (max-height:600px){
 .student-main{padding:14px 24px;justify-content:flex-start}.student-task{padding:18px 24px}.student-task h1{font-size:28px}.choice-grid{grid-template-columns:repeat(3,1fr);gap:8px;margin:12px 0}.choice-option{padding:12px}
}

/* Server-authoritative progress controls. These remain visible in every classroom view. */
.floating-controls{
 position:fixed;z-index:60;display:flex;align-items:center;gap:8px;
 background:rgba(255,253,247,.72);border:1px solid rgba(217,210,197,.78);
 box-shadow:0 10px 30px rgba(61,53,39,.14);backdrop-filter:blur(16px) saturate(1.1);
 -webkit-backdrop-filter:blur(16px) saturate(1.1);border-radius:22px;padding:8px;
}
.floating-controls button{min-width:44px;min-height:42px;border-radius:15px;background:rgba(255,255,255,.78)}
.floating-controls button:hover{background:#fff}
.teacher-floating{left:50%;bottom:18px;transform:translateX(-50%)}
.student-floating{right:18px;bottom:18px}
.floating-status{display:grid;gap:2px;min-width:150px;padding:0 8px}
.floating-status small{font-size:11px;color:var(--muted);font-weight:700}
.floating-status strong{font-size:13px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis;max-width:260px}
.float-state{color:var(--green-dark)!important}
body.presentation-mode .teacher-floating{display:flex}
body.presentation-mode .teacher-floating .float-state{display:none}

@media(max-width:620px){
 .teacher-floating{left:12px;right:12px;bottom:12px;transform:none;justify-content:center}
 .student-floating{left:12px;right:12px;bottom:12px;justify-content:space-between}
 .floating-status{min-width:0;flex:1}
 .floating-status strong{max-width:52vw}
 .student-main{padding-bottom:92px}
}


/* Sketch-driven lesson pages · 2026-09-19 */
.classroom-join-card{max-width:720px}
.classroom-join-grid{grid-template-columns:1fr}
.password-fill{display:grid;grid-template-columns:1fr auto;gap:10px}
.password-fill button{white-space:nowrap}

.lesson-cover{
 position:relative;min-height:clamp(430px,68vh,720px);overflow:hidden;border-radius:34px;
 display:flex;flex-direction:column;align-items:center;justify-content:center;text-align:center;
 background:linear-gradient(145deg,#fffdf7,#f3f5ea);border:1px solid var(--line);box-shadow:var(--shadow);
}
.lesson-cover p{font-weight:800;letter-spacing:.2em;color:var(--green-dark);margin:0 0 18px}
.lesson-cover h1{position:relative;z-index:2;font-size:clamp(42px,6vw,78px);line-height:1.14;margin:0;letter-spacing:.04em}
.cover-sign{position:relative;z-index:2;margin-top:40px;font-size:clamp(18px,2vw,28px);font-weight:800;color:#665d4f}
.cover-orbit{position:absolute;border:3px solid rgba(82,113,79,.13);border-radius:50%;pointer-events:none}
.cover-orbit.one{width:80%;height:48%;right:-26%;top:-12%;transform:rotate(15deg)}
.cover-orbit.two{width:88%;height:46%;left:-24%;bottom:-19%;transform:rotate(-9deg)}

.story-board{
 min-height:clamp(470px,68vh,720px);border-radius:32px;position:relative;overflow:hidden;cursor:pointer;
 background:linear-gradient(180deg,#eef5ec 0 36%,#e8dfc8 36% 100%);border:1px solid var(--line);box-shadow:var(--shadow);
}
.story-context{
 position:absolute;z-index:5;top:20px;left:50%;transform:translateX(-50%);width:min(840px,88%);
 padding:14px 22px;background:rgba(255,253,247,.9);backdrop-filter:blur(10px);border:1px solid rgba(217,210,197,.9);
 border-radius:18px;text-align:center;font-size:clamp(17px,1.7vw,24px);font-weight:800;box-shadow:0 10px 28px rgba(60,52,40,.10)
}
.story-visual{position:absolute;inset:0;padding-top:92px}
.story-person{position:absolute;bottom:28px;display:grid;justify-items:center;font-weight:900;color:#3b4637}
.story-person span{font-size:clamp(92px,13vw,180px);filter:drop-shadow(0 12px 8px rgba(48,42,33,.13))}
.story-person.girl{left:9%}.story-person.dad{right:10%}
.story-bubbles{position:absolute;inset:105px 22% 75px;display:flex;flex-direction:column;gap:10px;justify-content:center}
.story-bubble{
 max-width:72%;padding:12px 16px;border-radius:18px;background:rgba(255,255,255,.96);box-shadow:0 8px 20px rgba(52,46,35,.11);
 font-size:clamp(17px,1.75vw,25px);font-weight:750;line-height:1.4
}
.story-bubble.left{align-self:flex-start;border-bottom-left-radius:5px}.story-bubble.right{align-self:flex-end;border-bottom-right-radius:5px}
.story-bubble small{display:block;color:var(--green-dark);font-size:.62em;margin-bottom:4px}
.story-hint{position:absolute;z-index:8;right:16px;bottom:14px;padding:7px 12px;border-radius:999px;background:rgba(255,253,247,.8);color:var(--muted);font-size:12px}
.story-hold{cursor:default}
.story-hold .story-hint{background:rgba(52,91,59,.85);color:white}

.age-live{min-height:520px;display:grid;align-content:center;justify-items:center;gap:28px}
.age-stat{font-size:clamp(28px,4vw,52px);font-weight:850;text-align:center}
.age-stat strong{display:inline-grid;place-items:center;min-width:1.6em;padding:0 .2em;color:var(--green-dark);border-bottom:4px solid var(--orange)}
.age-stat span{display:block;font-size:.56em;margin-top:8px;color:#5c5549}
.teacher-age-table{width:min(620px,90%);font-size:clamp(22px,2.8vw,34px)}
.teacher-age-table th,.teacher-age-table td{text-align:center;padding:14px 22px}

.question-reveal{min-height:560px;display:grid;place-items:center;position:relative;cursor:pointer}
.reveal-stack{width:min(1040px,94%);display:grid;gap:22px}
.reveal-question{display:grid;grid-template-columns:82px 1fr;align-items:center;gap:18px;padding:24px 28px;background:#fff;border:1px solid var(--line);border-radius:24px;box-shadow:var(--shadow)}
.reveal-question span{font-size:22px;color:var(--orange);font-weight:900}
.reveal-question b{font-size:clamp(26px,3.2vw,46px);line-height:1.32}
.reveal-placeholder{font-size:clamp(26px,3vw,42px);color:var(--muted);text-align:center}

.expression-teacher,.value-board,.draw-board,.stats-board{
 min-height:520px;background:var(--paper);border:1px solid var(--line);border-radius:30px;padding:clamp(28px,5vw,58px);box-shadow:var(--shadow)
}
.expression-teacher{display:grid;align-content:center;text-align:center}
.expression-teacher h2,.value-board h2,.stats-board h2,.draw-board h2{font-size:clamp(30px,4vw,54px);line-height:1.25}
.expression-teacher>p:not(.eyebrow){font-size:clamp(19px,2vw,28px);line-height:1.6}
.expression-empty{margin:28px auto 0;width:min(720px,90%);min-height:140px;display:grid;place-items:center;border:2px dashed var(--line);border-radius:24px;color:var(--muted);font-size:20px}

.draw-board{text-align:center;display:grid;align-content:center;justify-items:center}
.draw-display{width:min(880px,94%);min-height:210px;border:2px dashed var(--line);border-radius:28px;margin:24px 0;display:grid;place-items:center;align-content:center;gap:8px;background:#fffdf8}
.draw-display small{font-weight:800;color:var(--muted)}.draw-display strong{font-size:clamp(54px,8vw,96px);line-height:1;color:var(--green-dark)}
.draw-display div{font-size:clamp(26px,3vw,44px);font-weight:850;word-break:break-word}
.value-draw div{font-size:clamp(20px,2.4vw,34px)}
.draw-button{font-size:22px!important;padding:16px 30px!important;background:var(--green)!important;color:white!important}

.stats-table-wrap{max-height:52vh;overflow:auto;border:1px solid var(--line);border-radius:18px}
.stats-table{width:100%;border-collapse:collapse;background:white}
.stats-table th{position:sticky;top:0;z-index:2;background:#f1f4e9;text-align:left;padding:14px;font-size:16px}
.stats-table td{padding:13px 14px;border-top:1px solid var(--line);vertical-align:top}
.stats-expression{font:800 clamp(18px,2vw,28px)/1.4 "Cambria Math","Noto Sans SC",sans-serif}
.teacher-question-grid{display:grid;grid-template-columns:1fr 1fr;gap:16px;margin-top:24px}
.teacher-question-grid>div{padding:22px;border:1px solid var(--line);border-radius:18px;background:white;font-size:clamp(21px,2.3vw,32px);font-weight:800}
.question-stats-grid{display:grid;grid-template-columns:1fr 1fr;gap:16px}
.question-stat{border:1px solid var(--line);border-radius:18px;padding:16px;background:white}
.question-stat h3{margin:0 0 12px;font-size:19px}.question-stat-row{display:flex;justify-content:space-between;padding:8px 0;border-top:1px dashed var(--line)}
.metric .metric-text{font-size:20px}

.info-people{display:grid;grid-template-columns:1fr 1fr;gap:18px;margin:22px 0}
.info-person{padding:20px;border:1px solid var(--line);border-radius:22px;background:#fff}
.info-person h2{text-align:center;margin-top:0;font-size:30px}
.info-options{display:grid;gap:12px}
.info-chip{padding:17px!important;font-size:21px!important;border:2px solid var(--line)!important;background:#fff!important}
.info-chip.selected{border-color:var(--green)!important;background:var(--green-soft)!important;color:var(--green-dark)!important;transform:translateY(-1px)}
.selection-summary{min-height:54px;display:grid;place-items:center;border-radius:16px;background:#f7f3e8;font-size:17px;font-weight:800;padding:10px}

.age-entry-scroll{height:min(53vh,520px);overflow:auto;border:1px solid var(--line);border-radius:18px;background:white}
.age-entry-table{width:100%;border-collapse:collapse}
.age-entry-table th{position:sticky;top:0;z-index:3;background:#eef3e8;padding:12px;font-size:17px}
.age-entry-table td{padding:6px;border-top:1px solid var(--line);text-align:center}
.age-entry-table td:first-child{width:58px;color:var(--muted);font-weight:800}
.age-entry-table input{padding:10px;text-align:center;font-size:20px;font-weight:800}
.sticky-submit{position:sticky;bottom:0;background:rgba(255,253,247,.94);backdrop-filter:blur(9px);padding-top:12px}

.expression-workspace{
 height:clamp(280px,48vh,520px);width:100%;display:flex;align-items:center;overflow-x:auto;overflow-y:hidden;
 border:3px solid #cfd6c7;border-radius:26px;background:linear-gradient(180deg,#fff,#fbfaf4);padding:24px;transition:.15s ease
}
.expression-workspace.drag-over{border-color:var(--green);box-shadow:inset 0 0 0 4px rgba(82,113,79,.08)}
.expression-line{display:flex;align-items:center;gap:12px;width:max-content;min-width:100%;justify-content:center;margin:auto;white-space:nowrap}
.expression-placeholder{width:100%;text-align:center;color:var(--muted);font-size:18px}
.placed-token{
 flex:0 0 auto;border:0!important;background:transparent!important;padding:4px!important;
 font:850 clamp(28px,4vw,48px)/1.2 "Cambria Math","Noto Sans SC",sans-serif!important;color:#332f28!important
}
.expression-tools{display:grid;gap:12px;margin-top:16px}
.token-group{display:grid;grid-template-columns:90px 1fr;align-items:center;gap:12px}
.token-group h3{font-size:15px;margin:0;color:var(--muted)}
.token-row{display:flex;flex-wrap:wrap;gap:9px}
.token-chip{height:54px!important;border:2px solid #9ca79a!important;background:#fff!important;color:#343a33!important;box-shadow:none!important;font-size:23px!important;font-weight:850!important}
.square-token{width:54px!important;padding:0!important;border-radius:13px!important}
.word-token{min-width:112px!important;padding:0 14px!important;border-radius:13px!important;font-size:20px!important}
.expression-edit{display:flex;justify-content:flex-end;gap:8px;margin-top:8px}
.token-drag-ghost{
 position:fixed;z-index:120;transform:translate(-50%,-50%);pointer-events:none;
 min-width:54px;height:54px;padding:0 14px;display:grid;place-items:center;
 border:2px solid #9ca79a;border-radius:13px;background:rgba(255,255,255,.94);
 box-shadow:0 12px 28px rgba(46,42,34,.18);font-size:22px;font-weight:850;color:#343a33
}

.question-intro{font-size:clamp(19px,2.5vw,30px)}
.question-set{display:grid;grid-template-columns:1fr 1fr;gap:14px;margin-top:20px}
.question-card{display:grid;gap:12px;padding:18px;border:1px solid var(--line);border-radius:18px;background:white}
.question-card>span{font-size:19px;font-weight:850}
.question-card>div{display:flex;align-items:center;gap:8px}.question-card input{font-size:25px;font-weight:850;text-align:center}.question-card small{white-space:nowrap;color:var(--muted)}

body.presentation-mode .lesson-head{display:none}
body.presentation-mode .metric-grid{display:none}
body.presentation-mode .stage-screen>.task-card{display:none}
body.presentation-mode .stage-screen{padding-bottom:92px}

@media(max-width:760px){
 .story-bubbles{inset:110px 10% 88px}.story-person.girl{left:3%}.story-person.dad{right:3%}.story-person span{font-size:88px}
 .story-bubble{max-width:78%;font-size:16px}
 .info-people,.question-set,.teacher-question-grid,.question-stats-grid{grid-template-columns:1fr}
 .token-group{grid-template-columns:1fr}.expression-workspace{height:42vh;padding:14px}
 .placed-token{font-size:30px!important}.word-token{font-size:17px!important;min-width:100px!important}
 .age-entry-scroll{height:48vh}
}


/* ===== Classroom presentation refinement · 16:9 stage ===== */
.teacher-grid{grid-template-columns:minmax(0,1fr) 360px;align-items:start}
.stage-screen{min-width:0;padding:14px 18px 24px;display:flex;justify-content:center;overflow:hidden}
.lesson-stage{
 container-type:inline-size;
 width:100%;aspect-ratio:16/9;max-height:calc(100vh - 92px);
 background:rgba(255,253,247,.94);border:1px solid var(--line);border-radius:28px;
 box-shadow:0 18px 50px rgba(62,53,40,.10);overflow:hidden;position:relative;
 padding:2.25cqw;box-sizing:border-box;
}
body.presentation-mode .teacher-grid{display:block}
body.presentation-mode .stage-screen{padding:8px 14px 12px;min-height:calc(100vh - 54px);align-items:center}
body.presentation-mode .lesson-stage{
 width:min(calc(100vw - 28px),calc((100vh - 72px)*16/9));
 max-width:none;max-height:calc(100vh - 72px);padding:2.15cqw;border-radius:22px;
}
body.presentation-mode .lesson-stage>.lesson-head{display:none}
body.presentation-mode .lesson-stage>section{height:100%;min-height:0}
body.presentation-mode .teacher-top{min-height:48px;padding:6px 14px}
body.presentation-mode .stage-screen>.task-card{display:none}
body.presentation-mode .control-rail{display:none}
.teacher-top .brand{font-size:15px}
.join-students-btn{background:var(--green)!important;color:#fff!important;font-weight:850!important}
.join-open-wide{width:100%;font-size:16px!important;padding:13px!important}

/* Larger projection typography */
.lesson-stage .relation-banner{font-size:clamp(34px,3.4cqw,66px);padding:1.2cqw 1.6cqw}
.lesson-stage .age-stat{font-size:clamp(36px,4.2cqw,72px);line-height:1.18}
.lesson-stage .age-stat span{font-size:.5em;margin-top:.45em}
.lesson-stage .teacher-age-table{width:min(74cqw,860px);font-size:clamp(28px,2.7cqw,48px)}
.lesson-stage .teacher-age-table th,.lesson-stage .teacher-age-table td{font-size:inherit;padding:.75cqw 1.3cqw}
.lesson-stage .expression-teacher h2,
.lesson-stage .value-board h2,
.lesson-stage .stats-board h2,
.lesson-stage .draw-board h2{font-size:clamp(38px,4.1cqw,70px)}
.lesson-stage .expression-teacher>p:not(.eyebrow){font-size:clamp(24px,2.2cqw,38px)}
.lesson-stage .expression-empty{font-size:clamp(23px,1.9cqw,34px)}
.lesson-stage .draw-display{min-height:15cqw}
.lesson-stage .draw-display strong{font-size:clamp(70px,7.5cqw,120px)}
.lesson-stage .draw-display div{font-size:clamp(36px,3.5cqw,62px);line-height:1.3}
.lesson-stage .value-draw div{font-size:clamp(30px,2.8cqw,50px)}
.lesson-stage .teacher-question-grid>div{font-size:clamp(28px,2.55cqw,46px);padding:1.4cqw}
.lesson-stage .value-note{font-size:clamp(22px,1.8cqw,32px)}
.lesson-stage .stats-lead{font-size:clamp(22px,1.8cqw,32px);line-height:1.45}
.lesson-stage .stats-table th{font-size:clamp(22px,1.55cqw,30px);padding:.8cqw}
.lesson-stage .stats-table td{font-size:clamp(22px,1.55cqw,31px);padding:.8cqw}
.lesson-stage .stats-expression{font-size:clamp(30px,2.35cqw,46px)}
.lesson-stage .stats-count{font-size:clamp(28px,2cqw,40px);font-weight:900}
.lesson-stage .stats-nos{font-size:clamp(20px,1.4cqw,28px)}
.lesson-stage .question-stat h3{font-size:clamp(23px,1.7cqw,32px);line-height:1.25}
.lesson-stage .question-stat-row{font-size:clamp(26px,2.1cqw,40px);padding:.55cqw 0}
.lesson-stage .question-stat-row b{font-size:1em}
.value-stats-board .question-stats-grid{gap:1.05cqw}
.value-stats-board .question-stat{padding:1cqw}

/* Illustrated camping story */
.story-board{height:100%;min-height:0;border-radius:22px;overflow:hidden;background:#e5eee8;position:relative}
.story-art{position:absolute;inset:0;width:100%;height:100%;object-fit:cover}
.story-context{
 top:2.5%;width:68%;padding:1cqw 1.35cqw;border-radius:1.1cqw;
 background:rgba(255,253,247,.9);display:grid;gap:.22cqw;
 font-size:clamp(20px,1.55cqw,30px);line-height:1.38
}
.story-context strong{font-size:1.08em;color:var(--green-dark)}
.story-context span{font-weight:700;color:#4d4a42}
.story-name{position:absolute;bottom:4.5%;font-size:clamp(24px,1.75cqw,34px);font-weight:950;color:#fff;text-shadow:0 2px 8px rgba(0,0,0,.35)}
.story-name.girl{left:29%}.story-name.dad{left:61%}
.story-bubbles{position:absolute;z-index:6;inset:18% 21% 10%;display:flex;flex-direction:column;justify-content:center;gap:.65cqw;pointer-events:none}
.story-bubble{
 max-width:78%;padding:.7cqw 1cqw;border-radius:1.25cqw;
 font-size:clamp(22px,1.75cqw,34px);font-weight:850;line-height:1.32;
 background:rgba(255,255,255,.96);box-shadow:0 10px 28px rgba(48,42,34,.14);
 animation:storyBubbleIn .34s ease both
}
.story-bubble.left{align-self:flex-start;border-bottom-left-radius:.3cqw}
.story-bubble.right{align-self:flex-end;border-bottom-right-radius:.3cqw}
.story-bubble small{font-size:.58em;margin-bottom:.14cqw}
.story-hint{font-size:clamp(13px,.9cqw,18px);padding:.45cqw .8cqw}
@keyframes storyBubbleIn{from{opacity:0;transform:translateY(14px) scale(.96)}to{opacity:1;transform:none}}

/* Reveal question pages */
.question-reveal{height:100%;min-height:0}
.reveal-stack{width:88%;gap:1.25cqw}
.reveal-question{grid-template-columns:5.5cqw 1fr;padding:1.5cqw 1.8cqw;border-radius:1.5cqw}
.reveal-question span{font-size:clamp(24px,1.8cqw,34px)}
.reveal-question b{font-size:clamp(36px,3.25cqw,62px)}
.reveal-placeholder{font-size:clamp(34px,3cqw,58px)}

/* Range page */
.range-board{
 height:100%;position:relative;cursor:pointer;display:grid;grid-template-rows:auto 1fr;align-items:start;
 padding:2cqw 4cqw;border-radius:22px;background:
 radial-gradient(circle at 82% 12%,rgba(237,181,100,.24),transparent 24%),
 linear-gradient(145deg,#f8f5e9,#edf3ea)
}
.range-title{text-align:center;font-size:clamp(38px,3.6cqw,68px);font-weight:950;color:#263b31;margin-bottom:1.8cqw}
.range-questions{display:grid;align-content:center;gap:1.2cqw;width:88%;margin:auto}
.range-question{
 display:grid;grid-template-columns:5.2cqw 1fr;align-items:center;gap:1.3cqw;
 padding:1.3cqw 1.6cqw;background:#fff;border:1px solid #d8d5c8;border-radius:1.4cqw;
 box-shadow:0 12px 28px rgba(58,50,37,.09);animation:rangeQuestionIn .4s ease both
}
.range-question span{font-size:clamp(22px,1.6cqw,32px);font-weight:950;color:#bd7549}
.range-question b{font-size:clamp(36px,3.05cqw,58px)}
.range-summary-overlay{
 position:absolute;inset:8% 7%;z-index:12;display:grid;place-content:center;text-align:center;gap:1.2cqw;
 background:rgba(42,73,57,.96);color:#fff;border-radius:2cqw;box-shadow:0 24px 70px rgba(32,45,36,.28);
 animation:conclusionIn .5s cubic-bezier(.2,.8,.2,1) both
}
.range-summary-overlay small{font-size:clamp(22px,1.7cqw,32px);letter-spacing:.18em}
.range-summary-overlay strong{font-size:clamp(46px,4.3cqw,82px)}
.range-summary-overlay p{font-size:clamp(28px,2.35cqw,44px);line-height:1.5;margin:0 auto;width:78%}
@keyframes rangeQuestionIn{from{opacity:0;transform:translateX(-40px)}to{opacity:1;transform:none}}

/* Relation discussion: moving / replacing / splitting cards */
.relation-discussion{
 height:100%;position:relative;cursor:pointer;padding:2.2cqw 3.4cqw;border-radius:22px;
 background:linear-gradient(145deg,#fffdf7,#edf2e7);overflow:hidden
}
.discussion-question{
 min-height:12%;display:grid;place-items:center;text-align:center;font-size:clamp(34px,3.25cqw,62px);
 font-weight:950;line-height:1.25;color:#26382e
}
.discussion-cards{height:73%;display:grid;place-content:center;grid-template-columns:repeat(2,minmax(0,1fr));gap:1.4cqw 2cqw;width:84%;margin:auto}
.concept-card{
 min-height:8.2cqw;display:grid;place-items:center;text-align:center;padding:1cqw 1.4cqw;
 border:3px solid #d8d3c7;border-radius:1.5cqw;background:#fff;
 font-size:clamp(28px,2.45cqw,47px);font-weight:900;box-shadow:0 10px 25px rgba(53,47,38,.08);
 transition:transform .45s ease,opacity .35s ease,border-color .35s ease,background .35s ease;
 animation:conceptIn .42s ease both
}
.concept-card.correct{border-color:#5e8a6c;background:#eaf3e9;box-shadow:0 0 0 .32cqw rgba(94,138,108,.11)}
.concept-pair{display:grid;align-content:center;gap:.8cqw;animation:pairMove .45s cubic-bezier(.2,.8,.2,1) both}
.follow-prompt,.concept-label{text-align:center;font-size:clamp(22px,1.7cqw,32px);font-weight:850;color:#6f6659}
.concept-card.answer{font-family:"Cambria Math","Noto Sans SC",sans-serif;font-size:clamp(40px,3.8cqw,72px);border-color:#6f9275}
.choice-orbit{grid-column:1/-1;display:flex;align-items:center;justify-content:center;gap:2.4cqw}
.choice-orbit .concept-card{min-width:24cqw}
.or-word{font-size:clamp(24px,2cqw,36px);font-weight:900;color:#817666}
.concept-card.faded{opacity:.3;transform:scale(.9)}
.concept-card.chosen{border-color:#3f7553;background:#e4f0e6;transform:scale(1.07);box-shadow:0 18px 42px rgba(63,117,83,.19)}
.split-expression{grid-column:1/-1;display:flex;align-items:center;justify-content:center;gap:1.6cqw}
.split-expression .concept-card{min-width:17cqw;font-family:"Cambria Math","Noto Sans SC",sans-serif;font-size:clamp(48px,4.3cqw,82px)}
.equals-mark{font-size:clamp(46px,4cqw,74px);font-weight:900;color:#867868}
.split-expression.final-split .emphasized{border-color:#4d845d;background:#e4f2e6;transform:scale(1.08)}
.meaning-conclusion{
 position:absolute;inset:6%;z-index:20;display:grid;grid-template-columns:1fr 1fr;align-content:center;gap:1.8cqw 2.4cqw;
 background:rgba(39,69,54,.97);color:#fff;border-radius:2cqw;padding:3.2cqw;box-shadow:0 26px 80px rgba(33,44,37,.34);
 animation:conclusionIn .5s cubic-bezier(.2,.8,.2,1) both
}
.meaning-conclusion>small{grid-column:1/-1;text-align:center;font-size:clamp(22px,1.6cqw,32px);letter-spacing:.22em}
.meaning-conclusion>div{text-align:center;padding:1.3cqw;border:1px solid rgba(255,255,255,.22);border-radius:1.4cqw;background:rgba(255,255,255,.07)}
.meaning-conclusion strong{display:block;font:900 clamp(44px,4.1cqw,80px)/1.1 "Cambria Math","Noto Sans SC",sans-serif}
.meaning-conclusion p{font-size:clamp(25px,2.1cqw,39px);line-height:1.45;margin:.8cqw 0 0}
@keyframes conceptIn{from{opacity:0;transform:scale(.88)}to{opacity:1;transform:none}}
@keyframes pairMove{from{opacity:.2;transform:translateY(55px)}to{opacity:1;transform:none}}
@keyframes conclusionIn{from{opacity:0;transform:scale(.88)}to{opacity:1;transform:none}}

/* Teacher navigation moved to left edge */
.teacher-floating{
 left:14px!important;right:auto!important;top:50%!important;bottom:auto!important;transform:translateY(-50%)!important;
 flex-direction:column;gap:7px;padding:8px;border-radius:20px
}
.teacher-floating button{width:72px;min-width:72px;height:62px;display:grid;place-items:center;align-content:center;gap:1px;padding:5px!important}
.teacher-floating button>span{font-size:28px;line-height:1}
.teacher-floating button>small{font-size:11px}
.teacher-floating .floating-status{min-width:72px;width:72px;text-align:center;padding:5px 2px}
.teacher-floating .floating-status strong{font-size:13px;max-width:70px}
.teacher-floating .floating-status small{font-size:10px}
body.presentation-mode .teacher-floating .float-state{display:none}

/* Large join QR overlay */
.join-modal[hidden]{display:none!important}
.join-modal{
 position:fixed;inset:0;z-index:220;display:grid;place-items:center;padding:4vh 4vw;
 background:rgba(31,38,32,.68);backdrop-filter:blur(14px)
}
.join-modal-card{
 position:relative;width:min(1460px,94vw);height:min(850px,90vh);display:grid;grid-template-columns:minmax(420px,.9fr) 1.1fr;
 align-items:center;gap:3vw;padding:3vw;background:#fffdf7;border-radius:34px;box-shadow:0 28px 90px rgba(0,0,0,.30)
}
.join-modal-close{position:absolute;right:20px;top:18px;width:52px;height:52px;border-radius:50%!important;font-size:30px!important}
.join-modal-qr{display:grid;place-items:center}
#join-qr-large{width:min(54vmin,570px);height:min(54vmin,570px);background:#fff;padding:18px;border:2px solid #ddd7ca;border-radius:24px;image-rendering:pixelated}
.join-modal-copy h2{font-size:clamp(34px,3vw,58px);line-height:1.2;margin:.4em 0}
.join-modal-copy ol{font-size:clamp(21px,1.55vw,30px);line-height:1.75;padding-left:1.4em}
.join-modal-copy li::marker{font-weight:900;color:#4c785d}
.observer-note{font-size:clamp(18px,1.25vw,25px);padding:14px 18px;border-radius:14px;background:#eef4e9;color:#365442;font-weight:800}

/* Student expression area intentionally constrained so long words feel cumbersome */
.expression-workspace{
 width:min(560px,86vw)!important;height:clamp(150px,23vh,225px)!important;margin:14px auto!important;
 padding:16px!important;border-width:3px!important
}
.expression-line{min-width:100%;width:max-content;gap:12px}
.placed-token{font-size:clamp(34px,4.1vw,48px)!important}
.expression-placeholder{font-size:17px}
.token-tools,.expression-tools{max-width:860px;margin-left:auto;margin-right:auto}
.student-task:has(.expression-workspace){padding-top:24px;padding-bottom:24px}
.student-task:has(.expression-workspace) h1{font-size:clamp(30px,4vw,44px)}
.student-task:has(.expression-workspace) .prompt{font-size:clamp(18px,2.3vw,25px)}

/* Entry role switch */
.join-role-tabs{display:grid;grid-template-columns:1fr 1fr;gap:8px;margin:20px 0}
.join-role-tabs button{font-size:17px;padding:13px}
.join-role-tabs button.active{background:var(--green)!important;color:#fff!important;border-color:var(--green)!important}

/* Metrics can include observer count */
.metric-grid{grid-template-columns:repeat(5,minmax(0,1fr))}
.metric b{font-size:clamp(25px,2vw,34px)}

@media(max-width:1100px){
 .teacher-grid{grid-template-columns:1fr}.control-rail{position:static;max-height:none;border-left:0;border-top:1px solid var(--line)}
 .lesson-stage{max-height:none}
 .metric-grid{grid-template-columns:repeat(3,1fr)}
}
@media(max-width:780px){
 .join-modal-card{grid-template-columns:1fr;height:auto;max-height:94vh;overflow:auto;padding:24px}
 #join-qr-large{width:min(72vw,430px);height:min(72vw,430px)}
 .teacher-floating{left:8px!important}
 .teacher-floating button{width:56px;min-width:56px;height:54px}
 .meaning-conclusion{grid-template-columns:1fr;overflow:auto}
 .discussion-cards{width:92%}
}

body.presentation-mode .lesson-stage>.task-card{display:none}


/* ===== Classroom answer-cycle + stage 4 refinement ===== */
.classroom-activity-bar,
.poll-actions{
 position:absolute;z-index:18;left:50%;bottom:2.1cqw;transform:translateX(-50%);
 display:flex;align-items:center;justify-content:center;gap:1.1cqw;
 min-width:min(70%,760px);padding:.72cqw 1cqw;border-radius:1.1cqw;
 background:rgba(255,253,247,.94);border:2px solid rgba(64,89,72,.16);
 box-shadow:0 12px 34px rgba(49,43,34,.15);backdrop-filter:blur(12px)
}
.classroom-activity-bar>span,.poll-actions>span{
 font-size:clamp(17px,1.15cqw,24px);font-weight:800;color:#5b584f
}
.classroom-activity-bar strong{color:#c4693c;font-size:1.18em}
.classroom-action-btn{
 min-width:9.5cqw!important;padding:.8cqw 1.35cqw!important;border-radius:.9cqw!important;
 font-size:clamp(20px,1.6cqw,31px)!important;font-weight:950!important;
 box-shadow:0 8px 20px rgba(55,50,40,.14)!important;border:2px solid transparent!important
}
.classroom-action-btn.start-action{
 background:linear-gradient(135deg,#32755d,#4b9271)!important;color:#fff!important
}
.classroom-action-btn.result-action{
 background:linear-gradient(135deg,#db7d47,#ee9c5d)!important;color:#fff!important
}
.results-locked{color:#8a5d42!important}

/* 4.1: each arrow step is a complete question view */
.range-single-question{
 width:82%;min-height:52%;margin:auto;display:grid;grid-template-columns:auto 1fr;align-items:center;
 gap:1.7cqw;padding:2.2cqw 2.6cqw;border-radius:2cqw;
 background:linear-gradient(135deg,#fff6df,#fffdf7);border:3px solid #e4bc68;
 box-shadow:0 20px 48px rgba(156,111,46,.15);animation:stageCardIn .36s ease both
}
.range-single-question>span{
 align-self:start;margin-top:.3cqw;padding:.55cqw .8cqw;border-radius:.65cqw;
 background:#cf7148;color:#fff;font-size:clamp(22px,1.55cqw,30px);font-weight:950;white-space:nowrap
}
.range-single-question>b{font-size:clamp(48px,4.4cqw,82px);line-height:1.28;color:#263b31}
.internal-step-hint{
 position:absolute;right:1.2cqw;bottom:.8cqw;padding:.35cqw .7cqw;border-radius:999px;
 background:rgba(255,255,255,.78);font-size:clamp(12px,.82cqw,16px);font-weight:750;color:#72695d
}

/* 4.2: stronger question/answer hierarchy */
.relation-discussion{
 background:
  radial-gradient(circle at 8% 15%,rgba(109,151,193,.16),transparent 26%),
  radial-gradient(circle at 91% 83%,rgba(224,149,93,.17),transparent 28%),
  linear-gradient(145deg,#fffdf7,#edf4ee)
}
.discussion-question{
 display:flex!important;align-items:center;justify-content:center;gap:1.2cqw;flex-wrap:wrap;
 padding:.5cqw 1cqw
}
.discussion-question .question-number{
 flex:0 0 auto;padding:.55cqw .9cqw;border-radius:.75cqw;background:#416f96;color:#fff;
 font-size:clamp(20px,1.45cqw,29px);font-weight:950;box-shadow:0 6px 16px rgba(65,111,150,.18)
}
.discussion-question strong{
 font-size:clamp(34px,3cqw,58px);line-height:1.25;color:#26382e
}
.discussion-cards{height:66%;width:86%;gap:1.25cqw 1.8cqw}

/* Poll cards with count boxes */
.poll-option-card{
 position:relative;min-height:7.6cqw;display:flex;align-items:center;justify-content:center;text-align:center;
 padding:1cqw 4.8cqw 1cqw 1.4cqw;border:3px solid #c8d2d8;border-radius:1.5cqw;
 background:linear-gradient(135deg,#f6fbff,#eef5fa);color:#29445b;
 font-size:clamp(28px,2.35cqw,45px);font-weight:950;
 box-shadow:0 10px 26px rgba(44,70,90,.09);transition:.32s ease
}
.poll-option-card.result-shown{transform:translateY(-2px)}
.poll-count{
 position:absolute;right:.8cqw;top:50%;transform:translateY(-50%);
 min-width:3.2cqw;height:3.2cqw;padding:0 .55cqw;display:grid;place-items:center;
 border-radius:.8cqw;background:#324b60;color:#fff;border:3px solid #fff;
 font-size:clamp(18px,1.25cqw,25px);font-weight:950;
 box-shadow:0 6px 14px rgba(42,61,76,.24);animation:countPop .34s cubic-bezier(.2,.85,.2,1) both
}
.poll-option-card.poll-correct{
 border-color:#3f9567;background:linear-gradient(135deg,#e3f4e7,#f3fbf4);color:#24593b;
 box-shadow:0 0 0 .34cqw rgba(63,149,103,.13),0 14px 34px rgba(45,103,70,.16)
}
.poll-option-card.selected-answer{
 transform:scale(1.08);border-width:5px;background:linear-gradient(135deg,#d8f2df,#f0fff3);
 box-shadow:0 0 0 .55cqw rgba(58,151,99,.16),0 22px 48px rgba(45,110,72,.23)
}
.poll-option-card.selected-answer::before{
 content:"✓ 被选择的关系";position:absolute;left:50%;top:-1.35cqw;transform:translateX(-50%);
 padding:.35cqw .75cqw;border-radius:999px;background:#278657;color:#fff;
 font-size:clamp(14px,.95cqw,19px);white-space:nowrap
}
.relation-choice{min-width:25cqw;font:950 clamp(40px,3.6cqw,68px)/1.1 "Cambria Math","Noto Sans SC",sans-serif}

/* Question components are blue/purple; transformed answers are green/orange */
.question-part{
 padding:1cqw;border-radius:1.6cqw;background:rgba(74,113,159,.08);
 border:2px solid rgba(74,113,159,.22)
}
.question-token{
 border-color:#6488bb!important;background:linear-gradient(135deg,#edf4ff,#f7f2ff)!important;
 color:#324f7f!important;box-shadow:0 12px 28px rgba(75,104,151,.12)!important
}
.question-part .follow-prompt{
 margin-top:.2cqw;padding:.55cqw .8cqw;border-radius:.7cqw;background:#4e6f9d;color:#fff;
 font-size:clamp(23px,1.7cqw,33px);font-weight:950
}
.answer-part{
 padding:1cqw;border-radius:1.6cqw;background:rgba(70,139,91,.07);
 border:2px solid rgba(70,139,91,.20)
}
.answer-part .concept-label{
 color:#4d6c56;font-size:clamp(20px,1.35cqw,27px);font-weight:900
}
.answer-token{
 border-color:#55956a!important;background:linear-gradient(135deg,#e8f6e9,#fff8e9)!important;
 color:#285e3c!important;box-shadow:0 14px 34px rgba(64,121,82,.14)!important
}
.split-expression .answer-token{min-width:18cqw}

/* Bigger final idea appears on the second conclusion step */
.meaning-conclusion{grid-template-rows:auto 1fr auto}
.final-big-idea{
 grid-column:1/-1!important;text-align:center!important;padding:1.15cqw 1.5cqw!important;
 background:linear-gradient(135deg,#f1bc5b,#e88550)!important;color:#1f3027!important;
 border:0!important;box-shadow:0 12px 32px rgba(219,133,68,.28);
 font-size:clamp(30px,2.65cqw,50px)!important;font-weight:950!important;
 animation:bigIdeaIn .45s cubic-bezier(.18,.85,.25,1) both
}

/* Student poll UI */
.multi-choice-grid .choice-option:has(input:checked),
.choice-grid .choice-option:has(input:checked){
 border-color:#3e8460;background:#e9f5eb;box-shadow:0 0 0 3px rgba(62,132,96,.10)
}
.choice-option input{transform:scale(1.35)}
.student-task .choice-grid{gap:14px}
.student-task .choice-option span{font-size:clamp(20px,2.8vw,30px);font-weight:850}

@keyframes countPop{from{opacity:0;transform:translateY(-50%) scale(.55)}to{opacity:1;transform:translateY(-50%) scale(1)}}
@keyframes stageCardIn{from{opacity:0;transform:translateY(18px)}to{opacity:1;transform:none}}
@keyframes bigIdeaIn{from{opacity:0;transform:translateY(28px) scale(.94)}to{opacity:1;transform:none}}

/* Slightly richer but still restrained classroom palette */
.lesson-stage{
 background:
  radial-gradient(circle at 7% 7%,rgba(95,145,183,.08),transparent 24%),
  radial-gradient(circle at 94% 91%,rgba(226,153,90,.09),transparent 26%),
  rgba(255,253,247,.96)
}


/* ===== Story artwork + expression comparison + light summaries · 2026-09-20 ===== */

/* Uploaded camping artwork is the scene; HTML owns all dialogue text. */
.story-photo-board{
 position:relative;height:100%;min-height:0;background:#dff0ef;overflow:hidden
}
.story-photo{
 position:absolute;inset:0;width:100%;height:100%;object-fit:cover;object-position:center center;
 user-select:none;pointer-events:none
}
.story-photo-board::after{
 content:"";position:absolute;inset:0;z-index:1;pointer-events:none;
 background:linear-gradient(90deg,rgba(255,255,255,0) 0 49%,rgba(242,250,249,.08) 58%,rgba(246,250,244,.18) 100%)
}
.story-photo-board .story-context{
 z-index:8;top:2.2%;width:88%;padding:.82cqw 1.35cqw;
 border:3px solid rgba(224,145,62,.78);background:rgba(255,252,241,.94);
 box-shadow:0 10px 28px rgba(78,59,37,.14)
}
.story-photo-board .story-context strong{
 font-size:clamp(21px,1.45cqw,30px);color:#b55731;margin-right:.7em
}
.story-photo-board .story-context span{
 font-size:clamp(21px,1.45cqw,30px);font-weight:850;color:#453b31
}
.story-bubbles-right{
 z-index:7;position:absolute;left:58%;right:2.7%;top:18%;bottom:8%;
 display:flex;flex-direction:column;justify-content:center;gap:.48cqw;pointer-events:none
}
.story-bubbles-right .story-bubble{
 align-self:stretch!important;max-width:none!important;padding:.58cqw .82cqw .64cqw;
 border-radius:1cqw;border-width:3px;border-style:solid;
 font-size:clamp(28px,1.8cqw,38px);font-weight:850;line-height:1.3;
 box-shadow:0 8px 19px rgba(48,44,36,.12);backdrop-filter:blur(7px);
 animation:storyBubbleIn .32s ease both
}
.story-bubbles-right .story-bubble{
 display:flex;align-items:center;gap:.45em
}
.story-bubbles-right .story-bubble small{
 display:inline-block;margin:0;padding:.15em .48em;border-radius:999px;
 font-size:.68em;font-weight:950;vertical-align:.12em;flex:0 0 auto
}
.story-bubbles-right .story-bubble span{display:block;min-width:0}
.story-bubbles-right .story-bubble.xiaohong span{flex:1}
.story-bubbles-right .story-bubble.father span{flex:1;text-align:left}
.story-bubbles-right .story-bubble.father small{margin-left:auto}
.story-bubbles-right .story-bubble.xiaohong{
 border-color:#df5263;background:rgba(255,235,240,.94);color:#8c2c3b
}
.story-bubbles-right .story-bubble.xiaohong small{background:#df5263;color:white}
.story-bubbles-right .story-bubble.father{
 border-color:#1f6d58;background:rgba(231,246,251,.95);color:#174f43
}
.story-bubbles-right .story-bubble.father small{background:#1f6d58;color:white}
.story-photo-board .story-hint{z-index:10}

/* Make the expression area intentionally narrow enough that word expressions feel cumbersome. */
.expression-teacher-zone{
 width:min(31cqw,480px);min-height:9.4cqw;margin:1.5cqw auto 0;padding:1cqw;
 display:grid;place-items:center;align-content:center;gap:.45cqw;overflow:hidden;
 border:3px dashed #a9b6aa;border-radius:1.25cqw;background:#fffdf8;color:#776f62
}
.expression-teacher-zone span{
 padding:.28cqw .65cqw;border-radius:999px;background:#eef1e8;color:#53695a;
 font-size:clamp(15px,1cqw,20px);font-weight:900
}
.expression-teacher-zone strong{
 font-size:clamp(23px,1.8cqw,34px);white-space:nowrap
}
.expression-workspace{
 width:min(390px,72vw)!important;height:clamp(125px,18vh,175px)!important;
 padding:12px!important;border-radius:20px!important
}
.expression-line{min-width:100%;width:max-content!important;justify-content:center!important;white-space:nowrap}
.placed-token{font-size:clamp(34px,4.5vw,48px)!important;white-space:nowrap!important}

.expression-draw-board h2{max-width:78%;margin-left:auto;margin-right:auto}
.expression-draw-display{
 width:min(32cqw,510px)!important;min-height:11cqw!important;margin:1.1cqw 0!important;
 overflow:hidden!important;padding:1cqw!important
}
.draw-student{display:flex!important;align-items:center;justify-content:center;gap:.8cqw}
.draw-student small{font-size:clamp(15px,1cqw,20px)}
.draw-student strong{font-size:clamp(42px,3.8cqw,70px)!important}
.expression-kind{
 padding:.28cqw .65cqw;border-radius:999px;font-size:clamp(14px,.9cqw,18px)!important;
 font-weight:950!important
}
.expression-kind.rose{background:#ffe5eb;color:#a72e46}.expression-kind.blue{background:#e4efff;color:#315f9b}.expression-kind.green{background:#e3f3e7;color:#27704a}
.expression-showcase-line{
 display:block!important;width:100%;overflow-x:auto;overflow-y:hidden;white-space:nowrap;
 padding:.55cqw .25cqw;font:950 clamp(35px,3.05cqw,57px)/1.25 "Cambria Math","Noto Sans SC",sans-serif;
 color:#2e312e;scrollbar-width:thin
}

/* 2.3: three deliberate rows instead of a dense answer table. */
.expression-compare-board{
 height:100%;position:relative;padding:1.4cqw 2.5cqw 2.2cqw;
 background:linear-gradient(145deg,#fffdf8,#f6f9f4);border-radius:22px
}
.expression-compare-head{text-align:center;margin-bottom:1cqw}
.expression-compare-head h2{font-size:clamp(34px,3.2cqw,60px);margin:.1em 0}
.expression-compare-head p{font-size:clamp(18px,1.3cqw,26px);font-weight:750;color:#655e54;margin:.35em 0}
.expression-compare-list{display:grid;gap:.72cqw}
.expression-compare-row{
 display:grid;grid-template-columns:12.5cqw minmax(0,1fr) 11cqw;align-items:center;gap:1cqw;
 min-height:8.1cqw;padding:.75cqw 1cqw;border:3px solid;border-radius:1.25cqw;background:white;
 box-shadow:0 8px 20px rgba(51,45,38,.07)
}
.expression-compare-row.rose{border-color:#e35b72;background:#fff4f6}
.expression-compare-row.blue{border-color:#568ed2;background:#f3f8ff}
.expression-compare-row.green{border-color:#3d9a67;background:#f2fbf5}
.expression-category{display:grid;grid-template-columns:1fr auto;align-items:center;gap:.15cqw .5cqw}
.expression-category span{grid-column:1/-1;font-size:clamp(20px,1.45cqw,29px);font-weight:950}
.expression-category strong{font-size:clamp(36px,3cqw,56px);line-height:1}
.expression-category small{font-size:clamp(13px,.85cqw,17px);font-weight:800;color:#70685d}
.expression-compare-row.rose .expression-category{color:#a72e46}
.expression-compare-row.blue .expression-category{color:#315f9b}
.expression-compare-row.green .expression-category{color:#27704a}
.expression-compare-formula{
 min-width:0;overflow-x:auto;white-space:nowrap;text-align:center;padding:.4cqw .6cqw;
 font:950 clamp(31px,2.6cqw,49px)/1.25 "Cambria Math","Noto Sans SC",sans-serif;
 color:#2d332f
}
.expression-top-count{text-align:center;font-size:clamp(15px,1.05cqw,21px);font-weight:800;color:#676157}
.expression-top-count b{font-size:1.25em;color:#c26138}
.compare-question{
 margin:.85cqw auto 0;text-align:center;font-size:clamp(20px,1.55cqw,30px);font-weight:900;color:#4f463c
}

/* Unified light summary language — high-saturation borders, no dark full-screen panels. */
.expression-summary-scene{height:100%;position:relative;display:grid;place-items:start center;padding-top:10%}
.light-summary-card{
 width:78%;padding:2.2cqw 2.6cqw;text-align:center;border:5px solid #e46c3d;border-radius:2cqw;
 background:linear-gradient(145deg,#fff9ea,#fffdf8);box-shadow:0 20px 55px rgba(191,91,48,.15)
}
.summary-kicker{
 display:inline-block;padding:.38cqw .85cqw;border-radius:999px;background:#e46c3d;color:#fff;
 font-size:clamp(18px,1.25cqw,25px);font-weight:950;letter-spacing:.12em
}
.light-summary-card p{
 margin:1cqw 0 0;font-size:clamp(28px,2.35cqw,45px);font-weight:850;line-height:1.55;color:#7a3f29
}
.light-summary-card p b{font-size:1.18em;color:#266c54}
.summary-formula{
 margin:1cqw auto 0;width:max-content;max-width:90%;padding:.65cqw 1.6cqw;border-radius:1.15cqw;
 border:4px solid #2f8c61;background:#e9f8ed;color:#17603f;
 font:950 clamp(48px,4.5cqw,84px)/1.1 "Cambria Math","Noto Sans SC",sans-serif;
 box-shadow:0 10px 26px rgba(47,140,97,.14)
}
.summary-formula-placeholder{
 margin:1.2cqw auto 0;color:#a87962;font-size:clamp(18px,1.2cqw,24px);font-weight:800
}
.range-summary-overlay{
 inset:9% 7%!important;background:linear-gradient(145deg,#fff9e9,#fffdf8)!important;color:#6e3825!important;
 border:5px solid #e46c3d!important;box-shadow:0 22px 60px rgba(188,91,45,.15)!important
}
.range-summary-overlay small{color:#b14f2b!important;font-weight:950}
.range-summary-overlay strong{color:#b14f2b!important}
.range-summary-overlay p{color:#5b4b3f!important;font-weight:800}

/* 4.2 conclusions: compact and deliberately placed in the upper-middle. */
.relation-discussion.phase-6 .discussion-cards,
.relation-discussion.phase-7 .discussion-cards{
 height:60%;align-content:start;place-content:start center;padding-top:.7cqw
}
.relation-conclusion-compact{
 grid-column:1/-1;width:82%;margin:.2cqw auto 0;display:grid;gap:.8cqw
}
.conclusion-line{
 display:grid;grid-template-columns:8cqw 16cqw 1fr;align-items:center;gap:1cqw;
 padding:.8cqw 1cqw;border:4px solid;border-radius:1.25cqw;background:#fff;
 box-shadow:0 10px 26px rgba(52,46,38,.08)
}
.conclusion-line>span{
 padding:.35cqw .55cqw;border-radius:.65cqw;font-size:clamp(17px,1.05cqw,22px);font-weight:950;text-align:center
}
.conclusion-line>strong{
 font:950 clamp(34px,3cqw,57px)/1.1 "Cambria Math","Noto Sans SC",sans-serif;text-align:center
}
.conclusion-line>p{
 margin:0;font-size:clamp(23px,1.75cqw,34px);font-weight:850;line-height:1.35
}
.conclusion-line.relation{border-color:#4b8fd1;background:#f2f8ff;color:#2d6096}
.conclusion-line.relation>span{background:#4b8fd1;color:#fff}
.conclusion-line.quantity{border-color:#3f9b69;background:#f0faf3;color:#276e49}
.conclusion-line.quantity>span{background:#3f9b69;color:#fff}
.final-principle-card{
 grid-column:1/-1;width:82%;margin:.5cqw auto 0;padding:1.4cqw 2cqw;text-align:center;
 border:5px solid #ed8746;border-radius:1.8cqw;background:linear-gradient(145deg,#fff8df,#fffdf7);
 box-shadow:0 18px 45px rgba(216,118,55,.17)
}
.final-principle-card>span{
 display:inline-block;padding:.35cqw .75cqw;border-radius:999px;background:#ed8746;color:#fff;
 font-size:clamp(17px,1.15cqw,23px);font-weight:950
}
.final-principle-card>strong{
 display:block;margin:.7cqw 0;color:#b94b2b;font-size:clamp(41px,3.75cqw,70px);line-height:1.32
}
.final-principle-card>p{
 width:82%;margin:0 auto;color:#476457;font-size:clamp(20px,1.5cqw,29px);font-weight:800;line-height:1.5
}
.meaning-conclusion{
 background:linear-gradient(145deg,#fff9e8,#fffdf8)!important;color:#4f463c!important;
 border:5px solid #e46c3d!important
}
.final-big-idea{background:#fff1cf!important;color:#b94b2b!important;border:4px solid #ed8746!important}

@media(max-width:780px){
 .story-bubbles-right{left:48%;right:2%;top:19%;bottom:8%}
 .story-bubbles-right .story-bubble{font-size:15px}
 .expression-compare-row{grid-template-columns:1fr;gap:5px}
 .expression-category{grid-template-columns:auto auto;justify-content:center}
 .expression-category span{grid-column:auto}
 .conclusion-line{grid-template-columns:1fr}
 .expression-workspace{width:min(350px,82vw)!important}
}


/* ===== Persistent classroom image slots + final two lesson stages ===== */
.asset-manager-btn{background:#eef4ff!important;border-color:#9db8e8!important;color:#315f9b!important;font-weight:900!important}
.asset-modal{position:fixed;inset:0;z-index:240;display:grid;place-items:center;padding:4vh 4vw;background:rgba(28,35,31,.66);backdrop-filter:blur(12px)}
.asset-modal-card{position:relative;width:min(980px,92vw);max-height:90vh;overflow:auto;padding:34px;background:#fffdf8;border-radius:28px;box-shadow:0 28px 90px rgba(0,0,0,.28)}
.asset-slot-list{display:grid;gap:16px;margin-top:20px}
.asset-slot-card{padding:18px;border:2px solid #d9d5ca;border-radius:20px;background:#faf9f4}
.asset-slot-head{display:flex;align-items:center;justify-content:space-between;gap:14px;margin-bottom:14px}
.asset-slot-head>div{display:grid;gap:4px}.asset-slot-head strong{font-size:19px}.asset-slot-head small{color:var(--muted)}
.asset-state{padding:6px 10px;border-radius:999px;font-size:12px;font-weight:900}.asset-state.ready{background:#e2f4e8;color:#286847}.asset-state.empty{background:#f4eee2;color:#806b4b}
.asset-slot-controls{display:grid;grid-template-columns:180px 1fr;gap:12px;margin-bottom:12px}.asset-slot-controls label{display:grid;gap:6px;font-weight:800}

.classroom-image-region{position:relative;width:100%;height:100%;background:#edf0e8;border:2px dashed #aeb7a9;border-radius:18px;overflow:hidden}
.classroom-image-region.has-image{border-style:solid;border-color:#d4d7cf;background-color:#f2f3ef}
.image-region-placeholder{position:absolute;inset:0;display:grid;place-content:center;text-align:center;gap:7px;padding:24px;color:#6d776f;background:linear-gradient(145deg,#f5f7f2,#edf1eb)}
.image-region-placeholder strong{font-size:clamp(22px,2.1cqw,38px);color:#3e5749}.image-region-placeholder span{font-size:clamp(18px,1.35cqw,27px);font-weight:850}.image-region-placeholder small{font-size:clamp(13px,.9cqw,18px)}

.story-photo-board>.classroom-image-region.story-photo{position:absolute;inset:0;width:100%;height:100%;border:0;border-radius:0;z-index:0}

/* Stage 5: full source problem with inline answer statistics */
.practice-worksheet-board{height:100%;position:relative;padding:1.2cqw 2.1cqw 5.1cqw;overflow:auto;background:linear-gradient(145deg,#fffdf8,#f5f8f3);border-radius:22px}
.worksheet-title{display:flex;align-items:center;justify-content:space-between;gap:1cqw;margin-bottom:.7cqw}.worksheet-title span{font-size:clamp(29px,2.7cqw,48px);font-weight:950;color:#315f9b}.worksheet-title strong{font-size:clamp(17px,1.15cqw,23px);color:#71685d}
.worksheet-section{padding:.9cqw 1.15cqw;margin-bottom:.75cqw;border:2px solid #d8d7cd;border-radius:1.05cqw;background:#fff}
.worksheet-section h3{font-size:clamp(22px,1.55cqw,30px);margin:0 0 .5cqw;color:#34483e}.worksheet-section p{font-size:clamp(18px,1.25cqw,24px);font-weight:750;margin:.3cqw 0 .6cqw}
.worksheet-table{width:70%;margin:.45cqw auto;border-collapse:collapse;font-size:clamp(17px,1.12cqw,23px)}.worksheet-table th{background:#dce9f5;color:#365d82}.worksheet-table th,.worksheet-table td{border:1px solid #aeb8be;text-align:center;padding:.38cqw .55cqw}
.worksheet-line{display:flex;align-items:center;flex-wrap:wrap;gap:.35cqw;margin:.47cqw 0;font-size:clamp(18px,1.3cqw,26px);font-weight:790;line-height:1.45}
.answer-blank{display:inline-block;min-width:8cqw;border-bottom:3px solid #626c65;height:1.25em}
.inline-answer-results{display:inline-flex;flex-wrap:wrap;gap:.35cqw;margin-left:.45cqw}.inline-answer-results>span{display:inline-flex;align-items:center;gap:.35cqw;padding:.25cqw .48cqw;border-radius:.65cqw;background:#eef6ff;border:2px solid #79a5d0;color:#315f87}.inline-answer-results b{font-size:1.08em}.inline-answer-results small{font-weight:900}.inline-answer-results em{color:var(--muted);font-style:normal}

/* Student worksheet mirrors the original problem instead of separating answers. */
.student-worksheet{display:grid;gap:18px}.student-worksheet-section{padding:18px;border:2px solid var(--line);border-radius:20px;background:#fff}.student-worksheet-section h2{font-size:clamp(22px,3.2vw,31px);margin-bottom:10px}.student-worksheet-section>p{font-size:clamp(17px,2.4vw,22px);line-height:1.55}
.student-worksheet-line{display:grid;grid-template-columns:auto minmax(115px,210px) auto;align-items:center;gap:8px;margin:13px 0;font-size:clamp(17px,2.3vw,22px);font-weight:750}.student-worksheet-line input{font-size:21px;font-weight:850;text-align:center;padding:9px}

/* Stage 6: upper 2/3 context image, lower 1/3 expression and draw area. */
.extension-board{height:100%;display:grid;grid-template-rows:minmax(0,2fr) minmax(150px,1fr);gap:.8cqw;padding:.4cqw;background:#fffdf8;border-radius:22px}
.extension-image-wrap{min-height:0}.extension-context-image{border-radius:1.2cqw}
.extension-bottom{display:grid;grid-template-columns:minmax(0,1.25fr) minmax(260px,.8fr) auto;align-items:center;gap:1cqw;padding:.75cqw 1cqw;border:3px solid #e2a35d;border-radius:1.2cqw;background:linear-gradient(135deg,#fff8e9,#fffdf8)}
.extension-prompt{display:grid;gap:.3cqw}.extension-prompt strong{font-size:clamp(24px,1.85cqw,35px);color:#8c4e2e}.extension-prompt span{font-size:clamp(16px,1.05cqw,22px);font-weight:750;color:#5e615a}
.extension-featured{min-width:0;display:grid;gap:.2cqw;padding:.55cqw .8cqw;text-align:center;border:3px solid #4a8c69;border-radius:.9cqw;background:#eff9f1}.extension-featured small{font-size:clamp(13px,.85cqw,17px);font-weight:850;color:#4e6f59}.extension-featured strong{overflow-x:auto;white-space:nowrap;font:950 clamp(30px,2.65cqw,50px)/1.2 "Cambria Math","Noto Sans SC",sans-serif;color:#225f3e}
.extension-board .draw-button{font-size:clamp(18px,1.25cqw,25px)!important;padding:.75cqw 1cqw!important}

.lesson-closing{
 height:100%;display:grid;place-items:center;border-radius:22px;
 background:linear-gradient(145deg,#fffdf8,#f2f6ef);
}
.lesson-closing h1{
 margin:0;font-size:clamp(72px,8.5cqw,150px);font-weight:950;letter-spacing:.08em;
 color:#294c38;line-height:1;text-align:center;
}

.extension-student-task{display:grid!important;grid-template-rows:minmax(260px,2fr) auto auto auto;gap:14px;align-content:stretch}.student-extension-image{height:min(52vh,520px)}.extension-student-wait .student-extension-image{height:min(58vh,560px);margin-bottom:16px}
.free-expression-form input{font:850 clamp(25px,4vw,38px)/1.2 "Cambria Math","Noto Sans SC",sans-serif;text-align:center;padding:15px}

/* Keep generic activity controls clear of the integrated stage-5/6 layouts. */
.practice-worksheet-board+.classroom-activity-bar,.extension-board+.classroom-activity-bar{bottom:1.1cqw}

@media(max-width:780px){
 .asset-slot-controls{grid-template-columns:1fr}
 .worksheet-table{width:100%}
 .student-worksheet-line{grid-template-columns:1fr}.student-worksheet-line input{width:100%}
 .extension-board{grid-template-rows:minmax(0,1.7fr) minmax(210px,1fr)}
 .extension-bottom{grid-template-columns:1fr;overflow:auto}
}


/* ===== Longitudinal classroom data center ===== */
.data-center-btn{background:#edf7f0!important;border-color:#8eb79a!important;color:#2d6842!important;font-weight:900!important}
.data-center-shell{min-height:100vh;background:linear-gradient(145deg,#f8f4ea,#eef4ef)}
.data-center-main{width:min(1500px,94vw);margin:0 auto;padding:34px 0 70px}
.data-center-toolbar{display:grid;grid-template-columns:minmax(0,1fr) minmax(260px,380px);align-items:end;gap:30px;padding:30px 34px;border:1px solid var(--line);border-radius:26px;background:rgba(255,253,248,.93);box-shadow:0 18px 50px rgba(58,70,60,.08)}
.data-center-toolbar h1{font-size:clamp(34px,3vw,54px);margin:4px 0 8px}.data-class-filter select{font-size:17px;font-weight:800}
.data-center-content{display:grid;gap:20px;margin-top:20px}
.data-metric-grid{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:14px}.data-metric-grid .metric{min-height:126px}
.data-export-card,.data-table-card{padding:24px 26px;border:1px solid var(--line);border-radius:22px;background:#fffdf8;box-shadow:0 12px 34px rgba(58,70,60,.06)}
.data-export-card{display:flex;align-items:center;justify-content:space-between;gap:18px}.data-export-card h2,.data-table-card h2{margin:0 0 6px;font-size:25px}
.data-table-wrap{overflow:auto;margin-top:14px;border:1px solid #dedbd1;border-radius:16px;background:white}
.data-table-wrap table{width:100%;min-width:900px;border-collapse:collapse}.data-table-wrap th,.data-table-wrap td{padding:12px 14px;border-bottom:1px solid #ece9e0;text-align:left;vertical-align:middle}.data-table-wrap th{position:sticky;top:0;background:#f1f5ef;color:#40584a;font-size:14px;z-index:1}.data-table-wrap td{font-size:15px}.data-table-wrap tbody tr:hover{background:#faf8f0}

@media(max-width:900px){
 .data-center-toolbar{grid-template-columns:1fr}.data-metric-grid{grid-template-columns:repeat(2,minmax(0,1fr))}
 .data-export-card{align-items:flex-start;flex-direction:column}
}
@media(max-width:560px){.data-metric-grid{grid-template-columns:1fr}.data-center-main{width:96vw}.data-center-toolbar{padding:22px}}


/* ===== Phone-only teacher adaptation =====
   Applied by JS only to narrow portrait phones or short coarse-pointer landscape phones.
   Desktop and tablet layouts intentionally remain unchanged. */
body.phone-classroom{
 min-height:100svh;
 overflow-x:hidden;
}
body.phone-classroom .teacher-shell{
 min-height:100svh;
 grid-template-rows:auto auto;
}
body.phone-classroom .teacher-top{
 position:relative;top:auto;
 display:flex;flex-wrap:wrap;align-items:center;
 gap:8px;padding:10px 12px;
}
body.phone-classroom .teacher-top .brand{
 flex:1 1 auto;min-width:190px;margin-right:0;font-size:15px;
}
body.phone-classroom .teacher-top .session-state{
 margin-left:auto;white-space:nowrap;
}
body.phone-classroom .teacher-top .teacher-hide{
 display:none!important;
}
body.phone-classroom .teacher-top #asset-modal-open,
body.phone-classroom .teacher-top #join-modal-open,
body.phone-classroom .teacher-top #mode-toggle{
 flex:1 1 30%;min-width:104px;min-height:44px;
 padding:9px 10px!important;font-size:14px!important;white-space:nowrap;
}
body.phone-classroom .teacher-grid{
 display:block!important;min-height:0;
}
body.phone-classroom .stage-screen,
body.phone-classroom.presentation-mode .stage-screen{
 display:block;min-height:0!important;height:auto!important;
 padding:10px 12px 92px!important;
 overflow:visible!important;
}
body.phone-classroom .lesson-stage,
body.phone-classroom.presentation-mode .lesson-stage{
 width:720px!important;height:405px!important;
 min-width:720px!important;max-width:none!important;
 min-height:405px!important;max-height:none!important;
 aspect-ratio:auto!important;
 margin:0 auto;
 zoom:var(--phone-stage-zoom,.5);
 padding:16px!important;
 border-radius:22px;
}
/* Keep the virtual 16:9 canvas stable when mobile browser chrome changes height. */
body.phone-classroom.presentation-mode .lesson-stage{
 width:720px!important;
 max-height:none!important;
}
body.phone-classroom .control-rail{
 position:static;top:auto;max-height:none;
 border-left:0;border-top:1px solid var(--line);
}
body.phone-classroom.presentation-mode .control-rail{
 display:none;
}
/* On phones the navigation becomes a bottom toolbar instead of covering the lesson. */
body.phone-classroom .teacher-floating{
 left:12px!important;right:12px!important;
 top:auto!important;bottom:calc(10px + env(safe-area-inset-bottom))!important;
 transform:none!important;
 flex-direction:row!important;justify-content:center!important;
 gap:6px!important;padding:7px!important;border-radius:18px!important;
}
body.phone-classroom .teacher-floating button{
 width:auto!important;min-width:52px!important;height:50px!important;
 display:grid;place-items:center;align-content:center;
 padding:4px 8px!important;
}
body.phone-classroom .teacher-floating button>span{font-size:24px}
body.phone-classroom .teacher-floating button>small{font-size:10px}
body.phone-classroom .teacher-floating .floating-status{
 min-width:0!important;width:auto!important;flex:1;
 text-align:center;padding:3px 5px;
}
body.phone-classroom .teacher-floating .floating-status strong{
 max-width:none!important;font-size:12px;
}
body.phone-classroom .teacher-floating .floating-status small{font-size:9px}
body.phone-classroom .join-modal{
 padding:12px;
}
body.phone-classroom .join-modal-card{
 width:100%;height:auto;max-height:calc(100svh - 24px);
 grid-template-columns:1fr;gap:12px;padding:18px;
 border-radius:22px;overflow:auto;
}
body.phone-classroom #join-qr-large{
 width:min(68vw,300px);height:min(68vw,300px);padding:10px;
}
body.phone-classroom .join-modal-copy h2{font-size:24px}
body.phone-classroom .join-modal-copy ol{font-size:16px;line-height:1.55}
body.phone-classroom .join-modal-close{
 right:10px;top:10px;width:42px;height:42px;font-size:24px!important;
}

/* Portrait phone: keep controls compact and lesson directly under the header. */
@media (max-width:700px){
 body.phone-classroom .teacher-top #asset-modal-open,
 body.phone-classroom .teacher-top #join-modal-open,
 body.phone-classroom .teacher-top #mode-toggle{flex:1 1 calc(33.333% - 8px)}
}
/* Landscape phone: size from width only; never from dynamic vh, preventing address-bar flicker. */
@media (orientation:landscape) and (max-height:500px){
 body.phone-classroom .teacher-top{padding:6px 10px}
 body.phone-classroom .teacher-top .brand{min-width:150px}
 body.phone-classroom .teacher-top #asset-modal-open,
 body.phone-classroom .teacher-top #join-modal-open,
 body.phone-classroom .teacher-top #mode-toggle{
  flex:0 1 auto;min-width:110px;min-height:38px;padding:6px 9px!important;
 }
 body.phone-classroom .stage-screen,
 body.phone-classroom.presentation-mode .stage-screen{padding-top:6px!important}
}


/* ===== Phone landscape refinement + prominent fullscreen ===== */
.teacher-top .fullscreen-btn{
 font-weight:900!important;border-color:#6f907e!important;
 background:#f1f7f3!important;color:#274c3a!important;white-space:nowrap;
}
body.phone-classroom .teacher-top .fullscreen-btn{
 display:inline-flex!important;align-items:center;justify-content:center;
 flex:1 1 30%;min-width:96px;min-height:44px;
 padding:9px 10px!important;font-size:14px!important;
}
body.phone-classroom.phone-landscape .teacher-top{
 flex-wrap:nowrap;gap:7px;padding:6px 10px;
}
body.phone-classroom.phone-landscape .teacher-top .brand{
 flex:0 1 auto;min-width:145px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis;
}
body.phone-classroom.phone-landscape .teacher-top .session-state{
 margin-left:auto;flex:0 0 auto;
}
body.phone-classroom.phone-landscape .teacher-top #asset-modal-open,
body.phone-classroom.phone-landscape .teacher-top #join-modal-open,
body.phone-classroom.phone-landscape .teacher-top #mode-toggle,
body.phone-classroom.phone-landscape .teacher-top .fullscreen-btn{
 flex:0 0 auto;min-width:96px;min-height:38px;
 padding:6px 9px!important;font-size:13px!important;
}
body.phone-classroom.phone-landscape .stage-screen,
body.phone-classroom.phone-landscape.presentation-mode .stage-screen{
 padding:6px 10px 62px!important;
}
body.phone-classroom.phone-landscape .lesson-stage,
body.phone-classroom.phone-landscape.presentation-mode .lesson-stage{
 transform-origin:top center;
}
/* Landscape navigation is deliberately compact so it does not cover the lower half of the slide. */
body.phone-classroom.phone-landscape .teacher-floating{
 left:10px!important;right:10px!important;
 bottom:calc(6px + env(safe-area-inset-bottom))!important;
 padding:5px 7px!important;gap:5px!important;
 background:rgba(255,253,247,.84);
}
body.phone-classroom.phone-landscape .teacher-floating button{
 min-width:48px!important;height:42px!important;padding:2px 7px!important;
}
body.phone-classroom.phone-landscape .teacher-floating button>span{font-size:21px}
body.phone-classroom.phone-landscape .teacher-floating button>small{font-size:9px}
body.phone-classroom.phone-landscape .teacher-floating .floating-status{
 flex:0 1 150px!important;
}
body.phone-classroom.phone-landscape .teacher-floating .floating-status small{display:none}
body.phone-classroom.phone-landscape .teacher-floating .floating-status strong{font-size:11px}


/* ===== Unified phone classroom adaptation v3 ===== */
/* Teacher: landscape navigation returns to the left edge, matching the desktop teaching habit. */
body.phone-classroom.phone-landscape .teacher-floating{
 left:8px!important;right:auto!important;
 top:50%!important;bottom:auto!important;
 transform:translateY(-50%)!important;
 flex-direction:column!important;justify-content:center!important;
 width:58px!important;
 gap:4px!important;padding:5px!important;border-radius:16px!important;
}
body.phone-classroom.phone-landscape .teacher-floating button{
 width:48px!important;min-width:48px!important;height:44px!important;
 padding:2px 4px!important;
}
body.phone-classroom.phone-landscape .teacher-floating .floating-status{
 width:48px!important;min-width:48px!important;flex:0 0 auto!important;
 padding:3px 1px!important;
}
body.phone-classroom.phone-landscape .teacher-floating .floating-status strong{
 max-width:46px!important;font-size:10px!important;white-space:normal;line-height:1.25;
}
body.phone-classroom.phone-landscape .stage-screen,
body.phone-classroom.phone-landscape.presentation-mode .stage-screen{
 padding-left:72px!important;padding-bottom:8px!important;
}

/* Student phone layout: independent from teacher/alice view. */
@media (max-width:700px){
 .student-shell{min-height:100svh;overflow-x:hidden}
 .student-top{
  position:sticky;top:0;z-index:30;display:flex;flex-wrap:wrap;
  gap:8px;padding:10px 12px;background:rgba(255,253,247,.96);
  backdrop-filter:blur(10px);
 }
 .student-brand{font-size:15px;min-width:0;flex:1 1 auto}
 .student-id{max-width:58vw;font-size:12px;text-align:right}
 .student-main{
  width:100%;padding:12px 12px calc(84px + env(safe-area-inset-bottom));
  justify-content:flex-start;
 }
 .student-stage-tag{font-size:12px;padding:6px 10px;margin-bottom:10px}
 .student-task{
  width:100%;padding:18px 14px;border-radius:18px;overflow:hidden;
 }
 .student-task h1{font-size:clamp(24px,7vw,32px);line-height:1.25}
 .student-task .prompt{font-size:17px;line-height:1.55}
 .choice-grid{gap:10px;margin:16px 0}
 .choice-option{min-height:50px;padding:13px 14px;font-size:16px}
 .submit-row{align-items:stretch;flex-direction:column}
 .submit-row button{width:100%;min-width:0;min-height:48px}
 .number-entry{width:100%;max-width:none;margin:16px auto}
 .number-entry input{font-size:28px;padding:14px}
 .builder-row{grid-template-columns:1fr!important}
 .builder-row>.field:nth-child(3),.builder-row>.field:nth-child(4){grid-column:auto!important}
 .symbol-pick{grid-template-columns:repeat(2,minmax(0,1fr))}
 .quantity-grid,.symbol-grid,.scenario-grid{grid-template-columns:1fr 1fr}
 .formula-preview{font-size:clamp(24px,7vw,34px);overflow-wrap:anywhere}
 .expression-workspace{
  width:100%!important;max-width:100%!important;height:34svh!important;
  min-height:150px!important;margin:12px 0!important;padding:12px!important;
  overflow:auto!important;
 }
 .token-tools,.expression-tools{width:100%;max-width:100%;overflow-x:auto}
 .word-token{min-width:88px!important}
 .age-entry-scroll{height:44svh;min-height:220px}
 .student-floating{
  left:10px;right:10px;bottom:calc(8px + env(safe-area-inset-bottom));
  border-radius:16px;padding:6px;
 }
 .student-floating button{min-height:44px}
}
/* Student landscape phones: preserve usable height and avoid dynamic-vh page jumps. */
@media (orientation:landscape) and (max-height:500px) and (pointer:coarse){
 .student-top{position:relative;padding:6px 10px}
 .student-main{padding:8px 12px 66px;justify-content:flex-start}
 .student-task{padding:12px 14px;border-radius:16px}
 .student-task h1{font-size:24px;margin:.25em 0}
 .student-task .prompt{font-size:15px}
 .choice-grid{grid-template-columns:repeat(2,minmax(0,1fr));gap:7px;margin:8px 0}
 .choice-option{min-height:42px;padding:8px 10px;font-size:14px}
 .expression-workspace{height:42vh!important;min-height:150px!important}
 .student-floating{bottom:6px}
}


/* ===== Classroom lifecycle + analysis visualizations ===== */
#state-actions{display:flex;flex-wrap:wrap;gap:8px;align-items:center}
.reset-classroom-btn{
 border-color:#c69a5e!important;background:#fff8ea!important;color:#775121!important;font-weight:900!important
}
.classroom-lifecycle-help{
 flex:1 1 100%;display:grid;gap:4px;margin-top:4px;padding:11px 12px;
 border:1px solid #ddd8ca;border-radius:13px;background:#faf8f1;color:#4d514b
}
.classroom-lifecycle-help strong{font-size:14px;color:var(--green-dark)}
.classroom-lifecycle-help span{font-size:13px;line-height:1.5}
.classroom-lifecycle-help small{font-size:11px;line-height:1.5;color:var(--muted)}

.data-viz-grid{display:grid;grid-template-columns:1fr 1fr;gap:20px}
.data-chart-card{
 padding:24px 26px;border:1px solid var(--line);border-radius:22px;background:#fffdf8;
 box-shadow:0 12px 34px rgba(58,70,60,.06);min-width:0
}
.data-chart-head{display:flex;align-items:flex-end;justify-content:space-between;gap:18px;margin-bottom:18px}
.data-chart-head h2{margin:2px 0 0;font-size:25px}
.data-chart-head .field{min-width:220px}.data-chart-head select{font-size:14px;font-weight:800}
.data-pie-layout{display:grid;grid-template-columns:minmax(190px,270px) minmax(0,1fr);gap:24px;align-items:center}
.data-pie{
 width:min(24vw,250px);aspect-ratio:1;border-radius:50%;margin:auto;position:relative;
 display:grid;place-items:center;box-shadow:inset 0 0 0 1px rgba(0,0,0,.04)
}
.data-pie:after{
 content:"";position:absolute;inset:24%;border-radius:50%;background:#fffdf8;
 box-shadow:0 0 0 1px rgba(0,0,0,.04)
}
.data-pie>div{position:relative;z-index:2;display:grid;text-align:center}
.data-pie strong{font-size:30px;color:var(--green-dark)}.data-pie span{font-size:12px;color:var(--muted)}
.data-chart-legend{display:grid;gap:9px;min-width:0}
.data-chart-legend>div{display:grid;grid-template-columns:12px minmax(0,1fr) auto;gap:8px;align-items:center}
.data-chart-legend i{width:10px;height:10px;border-radius:50%}
.data-chart-legend span{overflow:hidden;text-overflow:ellipsis;white-space:nowrap;font-size:13px}
.data-chart-legend b{font-size:12px;color:#59645c;white-space:nowrap}
.data-bars{display:grid;gap:13px;padding-top:4px}
.data-bar-row{display:grid;grid-template-columns:minmax(120px,180px) minmax(0,1fr) 48px;gap:12px;align-items:center}
.data-bar-label{display:grid;min-width:0}.data-bar-label strong{font-size:14px}.data-bar-label small{font-size:10px;color:var(--muted);overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.data-bar-track{height:20px;border-radius:999px;background:#eef0e9;overflow:hidden;border:1px solid #dde2d9}
.data-bar-track span{display:block;height:100%;border-radius:inherit;background:linear-gradient(90deg,#6f9278,#355f49)}
.data-bar-row>b{text-align:right;font-size:14px}
.data-empty-chart{min-height:230px;display:grid;place-items:center;color:var(--muted);font-weight:800}

@media(max-width:1000px){
 .data-viz-grid{grid-template-columns:1fr}
}
@media(max-width:620px){
 .data-chart-card{padding:18px 15px}
 .data-chart-head{display:grid;gap:10px}.data-chart-head .field{min-width:0}
 .data-pie-layout{grid-template-columns:1fr}.data-pie{width:min(70vw,240px)}
 .data-bar-row{grid-template-columns:92px minmax(0,1fr) 42px;gap:8px}
 .data-bar-label small{display:none}
}


/* ===== Textbook P56 practice ===== */
.textbook-practice-board{
 display:grid;grid-template-rows:auto auto minmax(0,1fr);gap:.62cqw;
}
.textbook-practice-board .worksheet-title{margin-bottom:0}
.textbook-practice-board .worksheet-section{margin-bottom:0}
.textbook-charity{padding:.72cqw 1.1cqw}
.textbook-charity h3,.textbook-route h3{letter-spacing:.01em}
.textbook-charity .worksheet-line{margin:.34cqw 0}
.textbook-route{padding:.62cqw 1.1cqw .72cqw;min-height:0}
.practice-route-diagram{
 width:100%;max-width:900px;margin:.05cqw auto .25cqw;color:#e8653d;
}
.practice-route-diagram svg{display:block;width:100%;height:auto;overflow:visible}
.practice-route-diagram .route-base{stroke:#4c5558;stroke-width:3;fill:none}
.practice-route-diagram .route-measure{stroke:currentColor;stroke-width:3;fill:none}
.practice-route-diagram text{text-anchor:middle;font-family:"Microsoft YaHei","Noto Sans SC",sans-serif}
.practice-route-diagram .route-values text{
 fill:#273033;font-size:27px;font-weight:850;font-style:italic
}
.practice-route-diagram .route-values text:first-child{font-style:normal}
.practice-route-diagram .route-places text{
 fill:#283134;font-size:22px;font-weight:800
}
.textbook-route .worksheet-line{margin:.31cqw 0}
.textbook-route .answer-blank{min-width:10cqw}
.student-worksheet-section .practice-route-diagram{
 max-width:820px;margin:10px auto 14px
}
.student-worksheet-section .practice-route-diagram .route-values text{font-size:29px}
.student-worksheet-section .practice-route-diagram .route-places text{font-size:23px}

@media(max-width:780px){
 .textbook-practice-board{display:block}
 .textbook-practice-board .worksheet-section{margin-bottom:10px}
 .practice-route-diagram{overflow-x:auto}
 .practice-route-diagram svg{min-width:620px}
 .student-worksheet-section .practice-route-diagram{overflow-x:auto;-webkit-overflow-scrolling:touch}
 .student-worksheet-section .practice-route-diagram svg{min-width:600px}
}


/* ===== Classroom input refinement · 2026-09-20 ===== */
.token-group.group-shapes{
 padding:10px 12px;border-radius:16px;background:#eef5ff;border:1px solid #c7daf4
}
.token-group.group-shapes h3{color:#315f9b}
.token-group.group-letters{
 padding:10px 12px;border-radius:16px;background:#eef8ef;border:1px solid #c7e2ce
}
.token-group.group-letters h3{color:#2f7048}
.token-group.group-shapes .token-chip{background:#f8fbff!important;border-color:#88aeda!important}
.token-group.group-letters .token-chip{background:#f7fcf8!important;border-color:#83b894!important}

.answer-blank{
 min-width:8cqw;height:1.15em;border-bottom:3px solid #626c65;
 color:transparent;line-height:1
}

.student-worksheet-line input{
 border:0!important;border-bottom:2px solid #6b746e!important;border-radius:0!important;
 background:transparent!important;box-shadow:none!important;padding:7px 5px!important;
 min-width:120px
}
.student-worksheet-line input.keypad-active,
.free-expression-form input.keypad-active{
 border-color:#3d7f58!important;box-shadow:0 3px 0 rgba(61,127,88,.12)!important
}

.math-keypad{
 display:grid;gap:10px;margin:18px 0 4px;padding:14px;
 border:2px solid #d7ddd4;border-radius:18px;background:#f8faf6
}
.math-keypad-group{display:grid;grid-template-columns:78px 1fr;align-items:center;gap:10px}
.math-keypad-group>span{font-size:14px;font-weight:900;color:#667066}
.math-keypad-group>div{display:flex;flex-wrap:wrap;gap:8px}
.math-keypad-group button,.math-keypad-edit button{
 min-width:46px;height:46px;padding:0 10px!important;border-radius:12px!important;
 font:850 20px/1 "Cambria Math","Microsoft YaHei",sans-serif!important;
 border:1px solid #aeb9ae!important;background:white!important;color:#303731!important
}
.math-keypad-group.letters{padding:8px;border-radius:13px;background:#edf7ef}
.math-keypad-group.letters>span{color:#2f7048}
.math-keypad-group.digits{padding:8px;border-radius:13px;background:#f7f3ea}
.math-keypad-group.operators{padding:8px;border-radius:13px;background:#eef4fb}
.math-keypad-edit{display:flex;justify-content:flex-end;gap:8px;border-top:1px solid #dde3dc;padding-top:10px}
.math-keypad-edit button{font-size:15px!important;min-width:72px}

.worksheet-item-feedback{
 grid-column:1/-1;display:none;font-size:15px;font-weight:900;margin-top:-4px
}
.worksheet-item-feedback.correct,.worksheet-item-feedback.wrong{display:block}
.worksheet-item-feedback.correct{color:#2e7a48}
.worksheet-item-feedback.wrong{color:#b34c3f}
.student-worksheet-line.answer-correct input{border-bottom-color:#4d9a67!important}
.student-worksheet-line.answer-wrong input{border-bottom-color:#c55b4d!important}

.value-draw-board{align-content:start!important;padding-top:.3cqw!important}
.value-draw-context{width:min(78cqw,1120px);margin:0 auto .65cqw;text-align:center}
.value-draw-context h2{font-size:clamp(28px,2.65cqw,46px)!important;margin:.1em 0 .35em}
.value-draw-context .relation-banner{width:min(34cqw,520px);margin:0 auto;padding:.55cqw 1cqw!important;font-size:clamp(30px,3cqw,54px)!important}
.value-draw-board .draw-display{min-height:10.5cqw!important;margin:.55cqw 0!important}

.free-expression-form input{
 caret-color:transparent;
 border:2px solid #aab6aa!important;
 background:#fff!important
}

@media(max-width:780px){
 .math-keypad-group{grid-template-columns:1fr}
 .math-keypad-group>div{gap:6px}
 .math-keypad-group button{min-width:42px;height:44px;font-size:19px!important}
 .student-worksheet-line input{width:100%!important}
}


/* ===== Live rehearsal refinements · 2026-09-20 ===== */
.timed-answer-bar{
 position:fixed!important;z-index:92;left:50%!important;top:72px!important;bottom:auto!important;
 transform:translateX(-50%)!important;width:min(82vw,980px);min-width:0!important;margin:0!important;
 justify-content:flex-start!important;padding:.52cqw .72cqw!important;
 border:3px solid #ef8b45!important;border-radius:18px!important;
 background:linear-gradient(135deg,rgba(255,240,216,.96),rgba(255,248,233,.96))!important;
 box-shadow:0 12px 32px rgba(110,62,31,.24)!important;backdrop-filter:blur(12px)
}
.timed-answer-bar .classroom-action-btn{flex:0 0 auto}
.timed-answer-bar .start-action{
 background:linear-gradient(135deg,#f06432,#ff963f)!important;
 border-color:#d95428!important;color:#fff!important
}
.timed-answer-bar .result-action{
 background:linear-gradient(135deg,#d94f36,#f27643)!important;
 border-color:#bc3d2b!important;color:#fff!important
}
.answer-bar-main{display:grid;gap:.08cqw;min-width:0;flex:1}
.answer-bar-main strong{font-size:clamp(18px,1.25cqw,25px);color:#8e3f24!important}
.answer-bar-main span{font-size:clamp(14px,.95cqw,19px);font-weight:800;color:#685447}
.answer-countdown{
 flex:0 0 auto;min-width:8.5cqw;padding:.42cqw .72cqw;text-align:center;
 border-radius:.85cqw;background:#fff;border:3px solid #ef8b45
}
.answer-countdown small{display:block;font-size:clamp(11px,.72cqw,15px);font-weight:850;color:#8b6a57}
.answer-countdown b{display:block;font:950 clamp(24px,2.1cqw,39px)/1.05 "Cambria Math","Microsoft YaHei",sans-serif;color:#d6532d}
.timed-answer-bar.is-finished{border-color:#cfc8bb!important;background:rgba(255,253,247,.96)!important}
.timed-answer-bar.is-finished .answer-countdown{border-color:#cfc8bb}
.timed-answer-bar.is-finished .answer-countdown b{color:#6f6a60}

/* 2.3 shows the actual first three drawn submissions; color is the only category cue. */
.draw-history-board{padding-top:1cqw}
.draw-history-grid{
 width:88%;margin:1.2cqw auto;display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:1.15cqw
}
.draw-history-card{
 min-width:0;min-height:12cqw;padding:1cqw;display:grid;align-content:center;gap:.55cqw;text-align:center;
 border:4px solid;border-radius:1.35cqw;box-shadow:0 12px 28px rgba(45,42,36,.09)
}
.draw-history-card small{font-size:clamp(14px,.95cqw,19px);font-weight:850;color:#756e65}
.draw-history-card strong{
 overflow-x:auto;white-space:nowrap;font:950 clamp(30px,2.75cqw,52px)/1.2 "Cambria Math","Noto Sans SC",sans-serif;color:#2f342f
}
.draw-history-card.rose{border-color:#df7183;background:#fff1f4}
.draw-history-card.blue{border-color:#6b9bd4;background:#eff6ff}
.draw-history-card.green{border-color:#5b9e72;background:#eef9f1}
.draw-history-card.neutral{border-color:#c8c7bf;background:#faf9f4}

/* 3.2: question and its statistics alternate one step at a time. */
.value-step-stats{height:100%;position:relative;display:grid;grid-template-rows:auto auto minmax(0,1fr);gap:.7cqw}
.value-step-stats .value-draw-context{margin:0 auto}
.value-stat-question{
 width:82%;margin:0 auto;padding:.9cqw 1.25cqw;display:flex;align-items:center;gap:1cqw;
 border:3px solid #d5c194;border-radius:1.2cqw;background:#fff9e9
}
.value-stat-question>span{
 flex:0 0 auto;padding:.42cqw .72cqw;border-radius:.65cqw;background:#d87547;color:#fff;
 font-size:clamp(18px,1.25cqw,25px);font-weight:950
}
.value-stat-question>strong{font-size:clamp(26px,2.15cqw,42px);line-height:1.3;color:#2d3a32}
.value-stat-wait{
 width:72%;margin:1.1cqw auto 0;align-self:start;padding:1.3cqw;text-align:center;
 border:3px dashed #c9b99b;border-radius:1.25cqw;color:#756858;
 font-size:clamp(20px,1.45cqw,29px);font-weight:850;background:rgba(255,253,247,.8)
}
.value-answer-stat-grid{
 width:82%;margin:.2cqw auto 0;align-self:start;display:flex;flex-wrap:wrap;justify-content:center;gap:.8cqw
}
.value-answer-stat{
 min-width:12cqw;padding:.8cqw 1cqw;display:grid;grid-template-columns:1fr auto;align-items:center;gap:.25cqw .8cqw;
 border:3px solid #b8c5ce;border-radius:1.1cqw;background:#f5f9fc;color:#334d60
}
.value-answer-stat strong{font:950 clamp(27px,2.35cqw,45px)/1.1 "Cambria Math","Noto Sans SC",sans-serif}
.value-answer-stat span{font-size:clamp(20px,1.4cqw,28px);font-weight:950}
.value-answer-stat small{grid-column:1/-1;font-size:clamp(13px,.9cqw,18px);font-weight:900}
.value-answer-stat.correct{
 border:6px solid #30955d;background:linear-gradient(135deg,#dcf3e3,#f2fff5);color:#175b37;
 box-shadow:0 0 0 .28cqw rgba(48,149,93,.13),0 12px 30px rgba(38,112,68,.15)
}

/* Student submit is always visible on the right and visually distinct. */
.student-shell .submit-row:has(button){
 position:fixed!important;z-index:95;right:20px;bottom:94px;margin:0!important;padding:10px!important;
 border-radius:18px;background:rgba(255,246,232,.94);border:2px solid #ef8a45;
 box-shadow:0 12px 34px rgba(110,62,31,.22);backdrop-filter:blur(12px)
}
.student-shell .submit-row:has(button) button{
 min-width:150px!important;min-height:56px!important;
 background:linear-gradient(135deg,#ef6232,#ff983f)!important;color:#fff!important;
 border:2px solid #d65028!important;box-shadow:0 8px 20px rgba(204,79,37,.22)!important;
 font-size:18px!important;font-weight:950!important
}
.student-main{padding-bottom:150px!important}

@media(max-width:780px){
 .timed-answer-bar{width:100%;gap:8px!important;padding:8px!important}
 .answer-countdown{min-width:94px}
 .draw-history-grid{width:96%;grid-template-columns:1fr;gap:8px;overflow:auto;max-height:58%}
 .draw-history-card{min-height:92px}
 .value-stat-question,.value-answer-stat-grid{width:94%}
 .student-shell .submit-row:has(button){right:12px;bottom:88px}
 .student-shell .submit-row:has(button) button{min-width:132px!important}
}


/* ===== Rehearsal round 2 · floating answer tools ===== */
.value-cumulative-stats{
 height:100%;display:grid;grid-template-rows:auto minmax(0,1fr) auto;gap:.45cqw;
}
.value-cumulative-stats .value-draw-context{
 width:min(68cqw,1020px);margin:0 auto .15cqw
}
.value-cumulative-stats .value-draw-context h2{
 font-size:clamp(21px,1.55cqw,31px)!important;margin:.02em 0 .18em!important
}
.value-cumulative-stats .value-draw-context .relation-banner{
 width:min(24cqw,390px);padding:.28cqw .65cqw!important;
 font-size:clamp(24px,2cqw,38px)!important
}
.value-cumulative-list{
 width:94%;margin:0 auto;min-height:0;overflow:auto;
 display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:.58cqw;
 align-content:start;padding:.08cqw .2cqw .45cqw
}
.value-cumulative-item{
 min-width:0;padding:.5cqw;border:2px solid #ded6c4;border-radius:.9cqw;
 background:rgba(255,253,247,.92);box-shadow:0 6px 16px rgba(65,57,44,.06)
}
.value-cumulative-item .value-stat-question{
 width:100%;margin:0;padding:.48cqw .65cqw;gap:.55cqw;border-width:2px;border-radius:.72cqw
}
.value-cumulative-item .value-stat-question>span{
 padding:.26cqw .46cqw;font-size:clamp(14px,.86cqw,18px)
}
.value-cumulative-item .value-stat-question>strong{
 font-size:clamp(17px,1.08cqw,23px);line-height:1.22
}
.value-cumulative-item .value-answer-stat-grid{
 width:100%;margin:.38cqw 0 0;gap:.38cqw;justify-content:flex-start
}
.value-cumulative-item .value-answer-stat{
 min-width:8.5cqw;padding:.42cqw .55cqw;border-width:2px;border-radius:.72cqw;
 grid-template-columns:1fr auto;gap:.12cqw .42cqw
}
.value-cumulative-item .value-answer-stat strong{
 font-size:clamp(20px,1.5cqw,30px)
}
.value-cumulative-item .value-answer-stat span{
 font-size:clamp(14px,.9cqw,18px)
}
.value-cumulative-item .value-answer-stat small{
 font-size:clamp(11px,.68cqw,14px)
}
.value-cumulative-item .value-answer-stat.correct{
 border-width:5px!important
}
.value-cumulative-item .value-stat-wait{
 width:100%;margin:.38cqw 0 0;padding:.52cqw;
 font-size:clamp(14px,.88cqw,18px);border-width:2px;border-radius:.72cqw
}

/* 5.1 keypad: draggable, resizable and translucent so the worksheet stays visible. */
.floating-math-keypad{
 position:fixed!important;z-index:97;right:18px;bottom:170px;
 width:min(560px,66vw);min-width:360px;min-height:210px;
 max-width:calc(100vw - 28px);max-height:72vh;
 margin:0!important;overflow:auto;resize:both;
 background:rgba(248,250,246,.90)!important;
 border:2px solid rgba(117,136,119,.70)!important;border-radius:20px!important;
 box-shadow:0 18px 46px rgba(47,61,49,.24)!important;
 backdrop-filter:blur(16px);-webkit-backdrop-filter:blur(16px)
}
.math-keypad-head{
 position:sticky;top:0;z-index:2;display:grid;grid-template-columns:auto 1fr auto;
 align-items:center;gap:10px;margin:-14px -14px 8px;padding:10px 12px;
 background:rgba(238,244,236,.94);border-bottom:1px solid rgba(120,139,121,.36);
 cursor:move;touch-action:none
}
.math-keypad-head strong{font-size:15px;color:#314638}
.math-keypad-active-label{
 min-width:0;overflow:hidden;text-overflow:ellipsis;white-space:nowrap;
 font-size:12px;font-weight:800;color:#6d786f
}
.math-keypad-toggle{
 min-width:58px!important;height:34px!important;padding:0 10px!important;
 border-radius:10px!important;font-size:13px!important;font-weight:900!important
}
.floating-math-keypad.is-collapsed{
 width:300px!important;min-width:260px!important;min-height:0!important;height:auto!important;
 resize:none;overflow:hidden
}
.floating-math-keypad.is-collapsed .math-keypad-group,
.floating-math-keypad.is-collapsed .math-keypad-edit{display:none}
.floating-math-keypad.is-collapsed .math-keypad-head{margin:-14px}

/* Keep the floating submit button visually separate from the input pad. */
.student-worksheet .submit-row:has(button){z-index:98!important}

@media(max-width:900px){
 .timed-answer-bar{top:64px!important;width:min(94vw,900px)}
 .value-cumulative-list{width:96%;grid-template-columns:1fr 1fr}
 .floating-math-keypad{
  right:10px;bottom:158px;width:min(600px,88vw);min-width:320px;max-height:66vh
 }
}
@media(max-width:620px){
 .timed-answer-bar{
  top:58px!important;width:96vw!important;padding:8px!important;gap:7px!important
 }
 .timed-answer-bar .answer-bar-main span{display:none}
 .value-cumulative-list{grid-template-columns:1fr;gap:8px}
 .value-cumulative-stats .value-draw-context{width:94%}
 .floating-math-keypad{
  left:8px!important;right:8px!important;bottom:150px;width:auto!important;min-width:0!important;
  max-width:none!important;max-height:58vh;resize:vertical
 }
 .math-keypad-head{grid-template-columns:auto 1fr auto}
}


/* ===== Rehearsal round 3 · cumulative stats + popup keypad polish ===== */
.value-cumulative-list{
 overflow:hidden!important;
 grid-template-rows:repeat(2,minmax(0,1fr));
}
.value-cumulative-item{
 display:grid;grid-template-rows:auto minmax(0,1fr);overflow:hidden;
 transition:border-color .18s ease,box-shadow .18s ease,background .18s ease
}
.value-cumulative-item.current-question{
 border-color:#e79655;background:rgba(255,248,234,.97);
 box-shadow:0 0 0 3px rgba(231,150,85,.12),0 8px 20px rgba(65,57,44,.08)
}
.value-cumulative-item .value-answer-stat-grid{
 min-height:0;max-height:100%;overflow:auto;align-content:start
}
.value-stat-pending{
 align-self:center;justify-self:center;padding:.34cqw .72cqw;border-radius:999px;
 border:2px dashed #d6cec0;color:#9b9386;background:rgba(250,248,242,.75);
 font-size:clamp(12px,.75cqw,15px);font-weight:850
}
.floating-math-keypad{
 transition:box-shadow .18s ease,background .18s ease,opacity .18s ease
}
.floating-math-keypad:not(.is-collapsed){
 background:rgba(248,250,246,.86)!important;
 box-shadow:0 20px 54px rgba(47,61,49,.28)!important
}
.floating-math-keypad.is-collapsed{
 background:rgba(255,248,235,.94)!important;border-color:#e99054!important;
 box-shadow:0 10px 28px rgba(160,91,43,.22)!important
}
.floating-math-keypad.is-collapsed .math-keypad-head{
 background:transparent!important;border-bottom:0!important;cursor:default
}
.floating-math-keypad.is-collapsed .math-keypad-head strong{color:#9b4f29}
.floating-math-keypad.is-collapsed .math-keypad-active-label{color:#8e796b}

@media(max-width:900px){
 .value-cumulative-list{grid-template-columns:repeat(2,minmax(0,1fr))!important;grid-template-rows:repeat(2,minmax(0,1fr))}
}
@media(max-width:620px){
 .value-cumulative-list{
  overflow:auto!important;grid-template-columns:1fr!important;grid-template-rows:none!important
 }
}


/* ===== Rehearsal round 4 · compact floating controls ===== */
.timed-answer-bar{
 left:auto!important;right:clamp(72px,6vw,112px)!important;top:72px!important;
 transform:none!important;width:min(660px,70vw)!important;
}
.math-keypad-resize{
 position:absolute;right:8px;bottom:8px;z-index:4;
 width:38px!important;height:38px!important;min-width:38px!important;padding:0!important;
 display:grid;place-items:center;border-radius:11px!important;
 border:1px solid rgba(93,116,96,.55)!important;background:rgba(255,255,255,.82)!important;
 color:#4b6651!important;font:900 20px/1 "Microsoft YaHei",sans-serif!important;
 cursor:nwse-resize;touch-action:none;box-shadow:0 4px 12px rgba(47,61,49,.12)
}
.floating-math-keypad.is-collapsed .math-keypad-resize{display:none}

@media(max-width:900px){
 .timed-answer-bar{
  left:50%!important;right:auto!important;transform:translateX(-50%)!important;
  width:min(94vw,760px)!important
 }
}


/* ===== Letter lesson revision · 2026-09-22 ===== */
.story-context.story-context-brief{
 top:16px;left:50%;right:auto;transform:translateX(-50%);
 width:min(90%,1120px);padding:10px 20px;border-radius:18px;
 background:rgba(255,253,247,.92);text-align:center
}
.story-context.story-context-brief span{
 display:block;font-size:clamp(24px,2.25vw,38px);font-weight:900;line-height:1.3;color:#34473a
}

.age-entry-open{width:min(900px,100%);margin:0 auto}
.age-entry-open .age-entry-table{width:100%}
.age-entry-open .age-entry-table input[readonly]{
 background:#f0f4ed!important;color:#315b3d!important;font-weight:950
}
.age-entry-decide{
 display:flex;justify-content:center;gap:14px;flex-wrap:wrap;
 padding:16px 8px 4px
}
.age-entry-decide button{
 min-width:190px;min-height:54px;border-radius:16px!important;font-size:18px!important;font-weight:900!important
}
.age-entry-decide .age-more{background:#fff!important;border:2px solid #77907b!important;color:#36533e!important}
.age-entry-decide .age-found{background:#f39a56!important;border-color:#f39a56!important;color:white!important}
.age-pattern-ready{
 padding:13px 20px;border-radius:16px;background:#eef7ee;border:1px solid #b8d6bd;
 font-size:17px;font-weight:850;color:#356044
}
.student-task .age-entry-open + .submit-row[hidden]{display:none!important}

.expression-tools{
 display:grid!important;
 grid-template-columns:minmax(0,1.25fr) minmax(0,.9fr) minmax(0,1fr)!important;
 grid-template-areas:
   "words words operators"
   "numbers shapes letters"!important;
 gap:10px!important;align-items:stretch
}
.expression-tools .token-group{margin:0!important;padding:10px!important;border-radius:16px!important;border:1px solid rgba(83,104,88,.16)!important}
.expression-tools .token-group h3{display:none!important}
.expression-tools .group-words{grid-area:words;background:#fff5ea!important}
.expression-tools .group-operators{grid-area:operators;background:#eef4fb!important}
.expression-tools .group-numbers{grid-area:numbers;background:#f7f3ea!important}
.expression-tools .group-shapes{grid-area:shapes;background:#eef5ff!important}
.expression-tools .group-letters{grid-area:letters;background:#eef8ef!important}
.expression-tools .token-row{display:flex!important;flex-wrap:wrap!important;align-content:center;justify-content:center;gap:8px!important}
.expression-tools .token-chip{min-height:48px!important;min-width:48px!important;font-size:20px!important}

.representative-board{
 min-height:520px;display:grid;align-content:center;gap:18px;padding:24px 36px;
 background:var(--paper);border:1px solid var(--line);border-radius:30px;box-shadow:var(--shadow)
}
.representative-head{text-align:center}
.representative-head h2{margin:.1em 0;font-size:clamp(32px,3.6vw,54px);color:#30463a}
.representative-head p{margin:.3em 0;font-size:clamp(17px,1.45vw,23px);color:var(--muted)}
.representative-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:18px}
.representative-card{
 position:relative;min-height:190px;padding:20px 18px 36px;border-radius:24px;border:3px solid transparent;
 display:grid;align-content:center;justify-items:center;gap:13px;text-align:center;overflow:hidden
}
.representative-card.rose{background:#fff0ef;border-color:#f0c3bf}
.representative-card.blue{background:#eef5ff;border-color:#bed3ee}
.representative-card.green{background:#eef8ef;border-color:#bfdcc5}
.representative-card small{font-size:15px;font-weight:900;color:#657067}
.representative-card strong{font-size:clamp(25px,2.6vw,42px);line-height:1.25;word-break:break-word}
.representative-votes{
 position:absolute;right:13px;bottom:11px;padding:6px 11px;border-radius:999px;
 background:#fff;color:#31523c;font-size:18px;font-weight:950;box-shadow:0 4px 12px rgba(44,63,48,.1)
}
.representative-actions{display:flex;justify-content:center;gap:14px}
.vote-start-button{
 font-size:21px!important;padding:15px 28px!important;background:#ef8b45!important;color:white!important;border-color:#ef8b45!important
}
.vote-question-live,.vote-discussion-prompt{
 text-align:center;font-size:clamp(18px,1.6vw,25px);font-weight:800;color:#4a594d
}
.vote-question-live{display:grid;gap:4px}.vote-question-live strong{font-size:1.15em;color:#d36f37}
.representative-grid.is-drawing .representative-card strong{animation:representativeShuffle .18s linear infinite alternate;filter:blur(1px)}
@keyframes representativeShuffle{from{transform:translateY(-3px);opacity:.5}to{transform:translateY(3px);opacity:1}}

.our-discovery-board{
 min-height:520px;display:grid;align-content:center;justify-items:center;gap:28px;
 padding:30px;background:#fffdf8;border:1px solid var(--line);border-radius:30px;box-shadow:var(--shadow)
}
.our-discovery-board>h2{
 margin:0;color:#e47f3d;font-size:clamp(44px,5vw,72px);letter-spacing:.04em
}
.discovery-lines{width:min(760px,88%);display:grid;gap:20px}
.discovery-line{
 min-height:74px;display:flex;align-items:center;gap:18px;padding:12px 24px;
 border-radius:20px;background:#f8f5ec;font-size:clamp(28px,3vw,44px);font-weight:850
}
.discovery-line strong{font:950 clamp(42px,4.8vw,70px)/1 "Cambria Math","Microsoft YaHei",sans-serif;color:#315f42}
.discovery-equation{justify-content:center;background:#eef7ee}
.discovery-equation span{font-size:clamp(38px,4vw,58px);font-weight:900}

.student-vote-countdown{
 display:flex;justify-content:center;align-items:center;gap:16px;margin:0 auto 16px;
 padding:10px 16px;border-radius:16px;background:#fff0df;color:#884720;font-weight:850
}
.student-vote-countdown strong{font-size:28px}
.student-representative-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:12px}
.student-representative-card{
 position:relative;min-height:180px;border:2px solid #d8ddd5;border-radius:20px;padding:16px;
 display:grid;align-content:center;gap:12px;text-align:center;background:#fff
}
.student-representative-card.text{background:#fff2ef}
.student-representative-card.symbol{background:#eef5ff}
.student-representative-card.letter{background:#eef8ef}
.student-representative-card input{position:absolute;opacity:0;pointer-events:none}
.student-representative-card:has(input:checked){border-color:#ec873e;box-shadow:0 0 0 4px rgba(236,135,62,.16)}
.student-representative-card .vote-card-title{font-size:15px;font-weight:900;color:#657067}
.student-representative-card strong{font-size:clamp(24px,5vw,38px);line-height:1.2}
.student-vote-status{text-align:center;margin-top:12px;color:#68746a;font-weight:800}

.meaning-connection-teacher{
 min-height:520px;display:grid;grid-template-rows:auto 1fr auto;gap:18px;
 padding:26px 44px;background:#fffdf8;border:1px solid var(--line);border-radius:30px;box-shadow:var(--shadow)
}
.meaning-title{text-align:center}.meaning-title h2{margin:0;color:#31563d;font-size:clamp(38px,4.2vw,62px)}
.meaning-title p{margin:7px 0 0;font-size:clamp(21px,2vw,30px);font-weight:850}
.meaning-columns{display:grid;grid-template-columns:1fr 1fr;gap:min(18vw,260px);align-content:center}
.meaning-column{display:grid;gap:14px;align-content:center}
.meaning-node{
 min-height:66px;padding:12px 18px;display:grid;place-items:center;border-radius:18px;background:#f7f4eb;
 border:2px solid #d7d1c3;font-size:clamp(22px,2.2vw,34px);font-weight:850;text-align:center
}
.meaning-node.math{background:#eef7ee;border-color:#bfd6c3;font:950 clamp(30px,3vw,48px)/1.1 "Cambria Math","Microsoft YaHei",sans-serif}
.meaning-teacher-status{text-align:center;color:#6b746d;font-weight:800}

.connection-form{display:grid;gap:14px}
.rope-board{
 position:relative;min-height:430px;display:grid;grid-template-columns:minmax(0,1.15fr) minmax(0,.85fr);
 gap:clamp(80px,18vw,240px);padding:20px;border-radius:24px;background:#fbfaf5;border:1px solid #dcd9cf;overflow:hidden
}
.rope-layer{position:absolute;inset:0;width:100%;height:100%;z-index:1;overflow:visible;pointer-events:none}
.rope-path{
 fill:none;stroke:#e28745;stroke-width:7;stroke-linecap:round;opacity:.9;
 pointer-events:stroke;cursor:pointer;filter:drop-shadow(0 3px 3px rgba(119,76,37,.12))
}
.rope-path.draft{stroke:#77907b;stroke-dasharray:10 9;opacity:.75;pointer-events:none}
.rope-column{position:relative;z-index:2;display:grid;align-content:space-evenly;gap:14px}
.rope-target,.rope-source{
 position:relative;min-height:68px;border-radius:18px;display:grid;place-items:center;
 background:white;border:2px solid #cfd6cd;font-size:clamp(18px,4vw,28px);font-weight:900;text-align:center;padding:10px 18px
}
.rope-target .rope-port{
 position:absolute;right:-12px;top:50%;width:24px;height:24px;transform:translateY(-50%);
 border-radius:50%;background:#829d86;border:5px solid #eff5ef
}
.rope-target.snap-candidate{
 border-color:#e28745;box-shadow:0 0 0 5px rgba(226,135,69,.14);transform:translateX(3px)
}
.rope-target.snap-candidate .rope-port{background:#e28745;transform:translateY(-50%) scale(1.12)}
.rope-source{background:#eef7ee;font:950 clamp(26px,6vw,38px)/1.1 "Cambria Math","Microsoft YaHei",sans-serif}
.rope-handle{
 position:absolute!important;left:-15px!important;top:50%!important;transform:translateY(-50%)!important;
 width:30px!important;height:30px!important;min-width:30px!important;padding:0!important;border-radius:50%!important;
 border:5px solid #fff!important;background:#e28745!important;box-shadow:0 0 0 2px #c96e34!important;
 touch-action:none;cursor:grab
}
.rope-handle:active{cursor:grabbing;transform:translateY(-50%) scale(1.08)!important}
.connection-actions{display:flex;justify-content:center;align-items:center;gap:10px;flex-wrap:wrap}
.connection-hint{font-size:13px;color:#798078}

.learning-summary-board{
 min-height:520px;display:grid;align-content:center;justify-items:center;gap:24px;
 padding:30px;background:#fffdf8;border:1px solid var(--line);border-radius:30px;box-shadow:var(--shadow)
}
.learning-summary-board>h2{margin:0;color:#e47f3d;font-size:clamp(44px,5vw,70px)}
.learning-summary-content{width:min(900px,90%);display:grid;gap:14px}
.summary-quantity,.summary-relation{
 min-height:64px;padding:10px 22px;border-radius:18px;background:#f6f3ea;
 display:flex;align-items:center;justify-content:center;gap:12px;font-size:clamp(25px,2.7vw,40px);font-weight:850
}
.summary-quantity strong,.summary-relation strong{font:950 clamp(34px,3.7vw,56px)/1 "Cambria Math","Microsoft YaHei",sans-serif;color:#315f42}
.summary-quantity.added strong em{font-style:normal;color:#e47f3d;font-weight:950}
.summary-relation{background:#eef7ee}.summary-relation strong{font-size:clamp(40px,4.5vw,66px)}
.summary-conclusion{
 margin:2px 0 6px;padding:10px 18px;text-align:center;border-left:5px solid #e7a067;
 background:#fff8ee;border-radius:12px;font-size:clamp(19px,1.75vw,27px);font-weight:850;color:#4c554c
}
.summary-conclusion.final{border-left-color:#6a9a73;background:#f0f8f1}

@media(max-width:780px){
 .expression-tools{
  grid-template-columns:1fr 1fr!important;
  grid-template-areas:"words operators" "numbers shapes" "letters letters"!important
 }
 .representative-grid,.student-representative-grid{grid-template-columns:1fr}
 .representative-card{min-height:120px}
 .meaning-connection-teacher{padding:18px}
 .meaning-columns{gap:48px}
 .rope-board{min-height:400px;gap:54px;padding:12px}
 .rope-target,.rope-source{min-height:60px;padding:8px 10px}
 .connection-actions{padding-bottom:70px}
}


/* ===== Rehearsal polish · 2026-09-22 round 2 ===== */

/* 2.1 student expression tools: compact tablet layout, no tall single-column token stacks. */
.student-task .expression-workspace{
 height:clamp(150px,22vh,210px)!important;min-height:150px!important;padding:14px 16px!important
}
.student-task .expression-tools{
 grid-template-columns:1.35fr .75fr 1fr 1fr!important;
 grid-template-areas:
  "words words operators operators"
  "numbers shapes shapes letters"!important;
 gap:10px!important;margin-top:12px!important
}
.student-task .expression-tools .token-group{
 min-width:0!important;padding:10px 12px!important;align-content:center!important
}
.student-task .expression-tools .token-row{
 display:grid!important;align-items:center!important;justify-content:stretch!important;gap:7px!important
}
.student-task .expression-tools .group-words .token-row{grid-template-columns:repeat(2,minmax(0,1fr))!important}
.student-task .expression-tools .group-operators .token-row{grid-template-columns:repeat(5,minmax(0,1fr))!important}
.student-task .expression-tools .group-numbers .token-row{grid-template-columns:repeat(5,minmax(0,1fr))!important}
.student-task .expression-tools .group-shapes .token-row{grid-template-columns:repeat(4,minmax(0,1fr))!important}
.student-task .expression-tools .group-letters .token-row{grid-template-columns:repeat(4,minmax(0,1fr))!important}
.student-task .expression-tools .token-chip{
 width:100%!important;min-width:0!important;height:44px!important;min-height:44px!important;
 padding:0 6px!important;font-size:19px!important
}
.student-task .expression-tools .word-token{font-size:17px!important;padding:0 8px!important}
.student-task .expression-edit{margin-top:8px!important}

/* 2.1 teacher: selected work appears in the original answer area. */
.expression-teacher-live{height:100%;display:grid;grid-template-rows:auto auto auto minmax(0,1fr) auto;align-content:start}
.expression-share-zone{
 min-height:17cqw!important;position:relative;display:grid!important;place-items:center!important;
 padding:2.2cqw 3cqw!important
}
.expression-share-zone>span{position:absolute;left:1.4cqw;top:1cqw}
.expression-share-student{
 position:absolute;left:1.4cqw;bottom:1cqw;display:flex;align-items:center;gap:.7cqw;
 font-size:clamp(15px,1cqw,20px)
}
.expression-share-student small{color:#776d60;font-weight:800}
.expression-share-student b{padding:.35cqw .62cqw;border-radius:999px;background:#f2eee3;color:#33483b}
.expression-share-student em{font-style:normal;font-weight:900;padding:.3cqw .55cqw;border-radius:999px}
.expression-share-answer{
 font:950 clamp(42px,4.8cqw,82px)/1.2 "Cambria Math","Microsoft YaHei",sans-serif!important;
 color:#2c4135!important;text-align:center
}
.expression-share-placeholder{font-size:clamp(24px,2cqw,36px)!important;color:#887f72!important}
.expression-share-actions{display:flex;justify-content:center;align-items:center;gap:1cqw;margin-top:.7cqw}
.expression-share-actions span{font-size:clamp(15px,1cqw,20px);font-weight:800;color:#746d62}

/* 2.3 1/7: balance text and symbolic expressions. */
.representative-card[data-representative-kind="text"] strong{
 font-size:clamp(24px,2.05cqw,38px)!important;line-height:1.25!important
}
.representative-card[data-representative-kind="symbol"] strong,
.representative-card[data-representative-kind="letter"] strong{
 font:950 clamp(46px,4.4cqw,76px)/1.08 "Cambria Math","Microsoft YaHei",sans-serif!important;
 letter-spacing:.02em
}
.representative-card small{font-size:clamp(16px,1.1cqw,21px)!important}

/* 2.3 2/7–7/7: fixed rows and reserved father-age answer slots. */
.discovery-lines-fixed{
 width:min(820px,90%)!important;grid-template-rows:repeat(3,minmax(82px,1fr));gap:16px!important
}
.discovery-lines-fixed .discovery-line{
 visibility:hidden;opacity:0;min-height:82px!important;
 grid-template-columns:minmax(250px,.9fr) minmax(360px,1.1fr);
 justify-content:stretch!important
}
.discovery-lines-fixed .discovery-line.is-visible{
 visibility:visible;opacity:1;animation:discoveryFadeIn .42s ease both
}
.discovery-answer-slots{
 min-width:0;display:grid;grid-template-columns:1fr 1fr;gap:18px;align-items:center
}
.discovery-answer-slots strong{
 min-height:58px;display:grid;place-items:center;border-radius:16px;
 background:#eef5ed;border:2px solid #c8d9c8
}
.discovery-answer-slots .slot-ghost{visibility:hidden!important}
.discovery-reveal{visibility:hidden;opacity:0}
.discovery-reveal.is-visible{
 visibility:visible;opacity:1;animation:discoveryFadeIn .5s ease both
}
.discovery-answer-slots .secondary-answer{background:#fff4e7;border-color:#efc08f;color:#b76832!important}
.discovery-answer-slots .secondary-answer.is-visible{animation-delay:.55s}
.discovery-equation{
 grid-template-columns:auto auto!important;justify-content:center!important;gap:18px!important
}
.equation-reveal{display:flex;align-items:center;gap:14px}
@keyframes discoveryFadeIn{
 from{opacity:0;transform:translateY(9px) scale(.97)}
 to{opacity:1;transform:none}
}

/* 2.4 teacher answer reveal and student correctness feedback. */
.meaning-connection-teacher.show-answer{grid-template-rows:auto minmax(0,1fr) auto}
.meaning-answer-blackboard{
 width:min(82%,980px);margin:auto;padding:1.5cqw 2cqw;border-radius:1.5cqw;
 background:#234735;color:#fff;border:8px solid #8a6748;
 box-shadow:inset 0 0 0 2px rgba(255,255,255,.12),0 14px 34px rgba(45,48,40,.16)
}
.meaning-answer-blackboard>small{
 display:block;text-align:center;margin-bottom:1cqw;font-size:clamp(18px,1.3cqw,25px);
 font-weight:900;letter-spacing:.12em;color:#f7e8bd
}
.meaning-answer-blackboard>div{display:grid;grid-template-columns:1fr 1fr;gap:.85cqw 1.3cqw}
.meaning-answer-blackboard span{
 display:grid;grid-template-columns:minmax(90px,.55fr) auto minmax(180px,1fr);
 align-items:center;gap:.55cqw;padding:.8cqw 1cqw;border:1px solid rgba(255,255,255,.18);
 border-radius:.9cqw;background:rgba(255,255,255,.06);font-size:clamp(20px,1.6cqw,30px)
}
.meaning-answer-blackboard b{
 font:950 clamp(28px,2.25cqw,43px)/1 "Cambria Math","Microsoft YaHei",sans-serif;color:#fff4b4
}
.meaning-answer-blackboard i{font-style:normal;color:#efc58a;font-size:1.2em}
.meaning-answer-blackboard strong{font-weight:900}
.rope-review-board{margin-top:10px}
.rope-review-board .rope-path{pointer-events:none}
.rope-review-board .rope-path.correct-edge{stroke:#4c9a65!important}
.rope-review-board .rope-path.wrong-edge{stroke:#d84e46!important;stroke-width:8!important}
.rope-review-port{
 position:absolute;left:-11px;top:50%;width:22px;height:22px;transform:translateY(-50%);
 border-radius:50%;background:#d28a4b;border:4px solid #fff
}
.connection-review h1{margin-bottom:4px}
.connection-correct-list{
 display:grid;grid-template-columns:auto repeat(2,minmax(0,1fr));gap:8px 10px;align-items:center;
 margin-top:12px;padding:12px;border-radius:16px;background:#eef6ef
}
.connection-correct-list>strong{grid-row:1/3;color:#31583c;padding:0 6px}
.connection-correct-list span{
 padding:8px 10px;border-radius:10px;background:white;border:1px solid #cbdcca;
 font-size:15px;font-weight:800
}
.connection-correct-list b{font-family:"Cambria Math","Microsoft YaHei",sans-serif;font-size:19px;color:#31583c}

/* 2.5: fixed 3-row × 2-column knowledge-summary board. */
.learning-summary-board{align-content:stretch!important;grid-template-rows:auto minmax(0,1fr) auto!important}
.learning-summary-board>h2{align-self:end}
.learning-summary-grid{
 width:min(1120px,94%);height:100%;margin:auto;display:grid;
 grid-template-columns:.9fr 1.35fr;grid-template-rows:repeat(3,minmax(0,1fr));
 gap:14px 18px;align-content:center
}
.summary-module{
 min-width:0;min-height:0;padding:16px 22px;border-radius:20px;border:2px solid #ded8ca;
 background:#f7f3e9;display:grid;place-items:center;text-align:center;
 visibility:hidden;opacity:0
}
.summary-module.is-visible{visibility:visible;opacity:1;animation:summaryModuleIn .42s ease both}
.summary-module-1{align-content:center;gap:8px}
.summary-module-1>div{display:flex;justify-content:center;align-items:center;gap:12px;font-size:clamp(23px,2cqw,34px);font-weight:850}
.summary-module-1 strong,
.summary-module-3 strong,
.summary-module-5 strong{font:950 clamp(38px,3.5cqw,60px)/1 "Cambria Math","Microsoft YaHei",sans-serif;color:#315e41}
.summary-module-3{display:flex;align-items:center;justify-content:center;gap:12px;font-size:clamp(24px,2.1cqw,36px);font-weight:850}
.summary-module-3 em{font-style:normal;color:#e47f3d}
.summary-module-5{background:#edf6ee;border-color:#bad5c0}
.summary-module-5 strong{font-size:clamp(42px,4cqw,68px)}
.summary-module.knowledge{
 padding:18px 26px;background:#fffaf0;border-color:#ecc994;
 color:#413d35;font-size:clamp(22px,1.85cqw,32px);font-weight:900;line-height:1.42
}
.summary-module-2{font-size:clamp(30px,2.7cqw,46px)!important;color:#315b3e!important}
.summary-highlight{
 display:inline-block;margin:0 .2em;padding:.05em .28em;border-radius:.4em;
 background:#f3a45f;color:white;font-weight:950
}
@keyframes summaryModuleIn{from{opacity:0;transform:translateY(8px)}to{opacity:1;transform:none}}

/* 3.2: reduce empty space and enlarge projection text/answers. */
.value-cumulative-stats .value-draw-context{width:min(78cqw,1160px)!important;margin-bottom:.45cqw!important}
.value-cumulative-stats .value-draw-context h2{
 font-size:clamp(28px,2.05cqw,40px)!important;line-height:1.2!important
}
.value-cumulative-stats .value-draw-context .relation-banner{
 width:min(29cqw,440px)!important;font-size:clamp(30px,2.45cqw,46px)!important
}
.value-cumulative-list{
 width:92%!important;grid-template-rows:repeat(2,auto)!important;align-content:center!important;gap:.8cqw!important
}
.value-cumulative-item{min-height:9.2cqw!important;padding:.72cqw!important}
.value-cumulative-item .value-stat-question>span{font-size:clamp(16px,1.02cqw,21px)!important}
.value-cumulative-item .value-stat-question>strong{font-size:clamp(22px,1.48cqw,30px)!important;line-height:1.25!important}
.value-cumulative-item .value-answer-stat-grid{align-content:center!important}
.value-cumulative-item .value-answer-stat{
 min-width:9.4cqw!important;padding:.55cqw .7cqw!important
}
.value-cumulative-item .value-answer-stat strong{font-size:clamp(28px,1.95cqw,40px)!important}
.value-cumulative-item .value-answer-stat span{font-size:clamp(16px,1.05cqw,21px)!important}
.value-stat-pending{font-size:clamp(16px,1.05cqw,21px)!important}

/* 4.1 4/4: keep the title visible above the conclusion card. */
.range-summary-overlay{
 inset:22% 12% 10%!important;border-radius:1.6cqw!important;gap:.8cqw!important;padding:1.5cqw 2.2cqw!important
}
.range-summary-overlay small{font-size:clamp(18px,1.35cqw,26px)!important}
.range-summary-overlay strong{font-size:clamp(34px,3.1cqw,58px)!important}
.range-summary-overlay p{font-size:clamp(22px,1.8cqw,34px)!important;line-height:1.4!important;width:84%!important}

@media(max-width:720px){
 .student-task .expression-tools{
  grid-template-columns:1fr 1fr!important;
  grid-template-areas:"words operators" "numbers shapes" "letters letters"!important
 }
 .student-task .expression-tools .group-words .token-row{grid-template-columns:1fr!important}
 .student-task .expression-tools .group-letters .token-row{grid-template-columns:repeat(6,minmax(0,1fr))!important}
 .learning-summary-grid{grid-template-columns:1fr 1.25fr;gap:9px}
 .summary-module{padding:10px 12px}
 .meaning-answer-blackboard>div{grid-template-columns:1fr}
 .connection-correct-list{grid-template-columns:1fr}
 .connection-correct-list>strong{grid-row:auto}
}


/* ===== Rehearsal polish · 2026-09-22 round 3 ===== */

/* 2.1 student: keep all five tool families in a compact two-row tablet board. */
@media (max-width:720px){
 .student-task:has(.expression-workspace){padding-top:14px!important}
 .student-task:has(.expression-workspace) h1{font-size:clamp(27px,6vw,38px)!important;margin:.18em 0!important}
 .student-task:has(.expression-workspace) .prompt{font-size:clamp(16px,3.6vw,21px)!important;line-height:1.45!important;margin:.35em 0 .55em!important}
 .student-task .expression-workspace{
  width:min(520px,92vw)!important;height:clamp(132px,18vh,175px)!important;min-height:132px!important;
  margin:8px auto!important
 }
 .student-task .expression-tools{
  width:min(620px,96vw)!important;max-width:none!important;
  grid-template-columns:1.25fr .8fr 1fr!important;
  grid-template-areas:
   "words words operators"
   "numbers shapes letters"!important;
  gap:8px!important;margin-top:8px!important
 }
 .student-task .expression-tools .token-group{padding:8px!important;border-radius:13px!important}
 .student-task .expression-tools .group-words .token-row{grid-template-columns:repeat(2,minmax(0,1fr))!important}
 .student-task .expression-tools .group-operators .token-row{grid-template-columns:repeat(3,minmax(0,1fr))!important}
 .student-task .expression-tools .group-numbers .token-row{grid-template-columns:repeat(5,minmax(0,1fr))!important}
 .student-task .expression-tools .group-shapes .token-row{grid-template-columns:repeat(2,minmax(0,1fr))!important}
 .student-task .expression-tools .group-letters .token-row{grid-template-columns:repeat(4,minmax(0,1fr))!important}
 .student-task .expression-tools .token-chip{
  height:40px!important;min-height:40px!important;font-size:17px!important;padding:0 4px!important
 }
 .student-task .expression-tools .word-token{font-size:15px!important}
 .student-task .expression-edit{margin-top:4px!important}
}
@media (max-width:480px){
 .student-task .expression-tools{
  grid-template-columns:1fr 1fr!important;
  grid-template-areas:"words operators" "numbers shapes" "letters letters"!important
 }
 .student-task .expression-tools .group-words .token-row{grid-template-columns:1fr!important}
 .student-task .expression-tools .group-letters .token-row{grid-template-columns:repeat(6,minmax(0,1fr))!important}
}

/* 2.3 1/7: prose stays readable but symbolic expressions are visually dominant. */
.representative-card[data-representative-kind="text"] strong{
 font-size:clamp(22px,1.8cqw,34px)!important;line-height:1.3!important;font-weight:850!important
}
.representative-card[data-representative-kind="symbol"] strong,
.representative-card[data-representative-kind="letter"] strong{
 font-size:clamp(54px,5cqw,88px)!important;line-height:1.02!important
}
.student-representative-card.text strong{font-size:clamp(19px,4.4vw,29px)!important;line-height:1.3!important}
.student-representative-card.symbol strong,
.student-representative-card.letter strong{font-size:clamp(34px,7vw,52px)!important}

/* 2.3 discovery: reserve the two father-age answer slots and fade every symbolic reveal in. */
.discovery-reveal.is-visible,
.discovery-line.is-visible{will-change:opacity,transform}
.discovery-answer-slots.father-slots{grid-template-columns:minmax(130px,.72fr) minmax(190px,1.28fr)!important}
.discovery-answer-slots.father-slots .discovery-reveal:first-child{justify-self:stretch}
.discovery-answer-slots.father-slots .secondary-answer{justify-self:stretch}
.equation-reveal.discovery-reveal.is-visible,
.discovery-equation>.discovery-reveal.is-visible{animation:discoveryFadeIn .55s ease both!important}

/* 3.2: denser four-card board with larger question and answer typography. */
.value-cumulative-stats .value-draw-context{width:min(84cqw,1240px)!important;margin-bottom:.18cqw!important}
.value-cumulative-stats .value-draw-context h2{
 font-size:clamp(34px,2.5cqw,48px)!important;line-height:1.15!important;margin:.02em 0 .12em!important
}
.value-cumulative-stats .value-draw-context .relation-banner{
 width:min(30cqw,470px)!important;padding:.3cqw .7cqw!important;
 font-size:clamp(36px,2.85cqw,52px)!important
}
.value-cumulative-list{width:94%!important;gap:.6cqw!important;align-content:center!important}
.value-cumulative-item{min-height:7.7cqw!important;padding:.55cqw!important}
.value-cumulative-item .value-stat-question{padding:.5cqw .7cqw!important}
.value-cumulative-item .value-stat-question>span{font-size:clamp(18px,1.15cqw,24px)!important}
.value-cumulative-item .value-stat-question>strong{font-size:clamp(28px,1.9cqw,38px)!important;line-height:1.2!important}
.value-cumulative-item .value-answer-stat{min-width:9cqw!important;padding:.45cqw .65cqw!important}
.value-cumulative-item .value-answer-stat strong{font-size:clamp(34px,2.35cqw,48px)!important}
.value-cumulative-item .value-answer-stat span{font-size:clamp(18px,1.2cqw,24px)!important}
.value-cumulative-item .value-answer-stat small{font-size:clamp(12px,.78cqw,16px)!important}
.value-stat-pending{font-size:clamp(18px,1.15cqw,24px)!important;padding:.55cqw!important}

/* 4.1 4/4: compact conclusion card sits clearly below the title. */
.range-summary-overlay{
 inset:27% 16% 13%!important;padding:1.2cqw 1.8cqw!important;border-width:4px!important;
 border-radius:1.4cqw!important;gap:.6cqw!important
}
.range-summary-overlay small{font-size:clamp(17px,1.15cqw,23px)!important}
.range-summary-overlay strong{font-size:clamp(30px,2.65cqw,50px)!important}
.range-summary-overlay p{font-size:clamp(20px,1.55cqw,29px)!important;line-height:1.35!important;width:88%!important}

/* ===== Rehearsal correction · round 4 ===== */

/* Keep the complete teacher/student rehearsal inside one fixed 16:9 canvas. */
body.dual-screen-mode{overflow:hidden!important}
.dual-screen-mode.presentation-mode .teacher-grid{height:calc(100vh - 54px);display:grid!important;place-items:center;overflow:hidden}
.dual-screen-mode.presentation-mode .stage-screen{
 width:min(100vw,calc((100vh - 54px)*16/9))!important;
 height:min(calc(100vh - 54px),56.25vw)!important;aspect-ratio:16/9!important;
 min-height:0!important;max-height:calc(100vh - 54px)!important;
 padding:.6%!important;overflow:hidden!important;display:flex!important;flex-direction:column;
 justify-content:space-between;align-items:center;background:#e7eee9
}
.dual-screen-mode.presentation-mode .lesson-stage{
 flex:0 0 auto!important;width:66%!important;height:auto!important;aspect-ratio:16/9!important;
 min-height:0!important;margin:0 auto!important;overflow:hidden!important
}
.dual-screen-mode .dual-student-preview{
 flex:0 0 auto!important;width:32%!important;height:auto!important;aspect-ratio:16/9!important;
 margin:0 auto!important;border-radius:10px!important
}
.dual-screen-mode .dual-student-preview iframe{width:200%!important;height:200%!important;transform:scale(.5)!important;transform-origin:0 0!important}
.dual-screen-mode .dual-preview-label{font-size:10px;top:4px;left:6px;padding:3px 7px}

/* 2.1 teacher answer area: stable 16:10 board, centered answer, invisible horizontal scrollbar. */
.expression-teacher-live{justify-items:center}
.expression-teacher-live>h2,.expression-teacher-live>p,.expression-teacher-live>.eyebrow{justify-self:stretch}
.expression-share-zone{
 width:auto!important;height:min(18cqw,300px)!important;min-height:0!important;max-width:76cqw!important;aspect-ratio:16/10!important;
 justify-self:center!important;overflow-x:auto!important;overflow-y:hidden!important;scrollbar-width:none
}
.expression-share-zone::-webkit-scrollbar{display:none}
.expression-share-answer{display:block!important;min-width:max-content;max-width:none!important;margin:auto!important;white-space:nowrap!important;padding:0 5cqw}
body.presentation-mode{overflow:hidden!important}

/* 2.1 student tools: every ordinary token is square; two five-character labels are 5:1. */
.student-task .expression-tools{
 width:min(820px,97vw)!important;grid-template-columns:repeat(20,minmax(0,1fr))!important;
 grid-template-areas:none!important;grid-template-rows:auto auto!important;gap:8px!important
}
.student-task .expression-tools .group-words{grid-area:auto!important;grid-column:1/13;grid-row:1}
.student-task .expression-tools .group-operators{grid-area:auto!important;grid-column:13/21;grid-row:1}
.student-task .expression-tools .group-numbers{grid-area:auto!important;grid-column:1/8;grid-row:2}
.student-task .expression-tools .group-shapes{grid-area:auto!important;grid-column:8/13;grid-row:2}
.student-task .expression-tools .group-letters{grid-area:auto!important;grid-column:13/21;grid-row:2}
.student-task .expression-tools .token-row{justify-items:center!important;align-content:center!important}
.student-task .expression-tools .group-words .token-row{grid-template-columns:repeat(2,minmax(0,1fr))!important}
.student-task .expression-tools .group-operators .token-row{grid-template-columns:repeat(5,minmax(0,1fr))!important}
.student-task .expression-tools .group-numbers .token-row{grid-template-columns:repeat(5,minmax(0,1fr))!important}
.student-task .expression-tools .group-shapes .token-row{grid-template-columns:repeat(2,minmax(0,1fr))!important}
.student-task .expression-tools .group-letters .token-row{grid-template-columns:repeat(4,minmax(0,1fr))!important}
.student-task .expression-tools .token-chip{
 width:min(100%,46px)!important;height:auto!important;min-width:0!important;min-height:0!important;
 aspect-ratio:1!important;padding:0!important;display:grid!important;place-items:center!important;line-height:1!important
}
.student-task .expression-tools .word-token{
 width:100%!important;max-width:190px!important;aspect-ratio:5/1!important;white-space:nowrap!important;
 font-size:clamp(14px,2.1vw,18px)!important;padding:0 8px!important
}

/* 2.3: move the question and cards upward and animate only the newly revealed item. */
.representative-board{align-content:start!important;padding-top:16px!important;gap:12px!important}
.representative-head h2{font-size:clamp(42px,4.4cqw,68px)!important;line-height:1.08!important}
.representative-head p{font-size:clamp(20px,1.55cqw,27px)!important}
.representative-grid{margin-top:2px}
.discovery-line.is-visible,.discovery-reveal.is-visible{animation:none!important;will-change:auto!important}
.discovery-line.just-revealed,.discovery-reveal.just-revealed{animation:discoveryFadeIn .24s ease-out both!important}
.discovery-answer-slots .secondary-answer.is-visible{animation-delay:0s!important}

/* 2.4: draw the four correct links directly on the original question. */
.meaning-connection-teacher{position:relative}
.meaning-connection-teacher.show-answer .meaning-columns{opacity:1!important}
.meaning-connection-teacher.show-answer .meaning-answer-blackboard{display:none!important}
.meaning-columns{position:relative}
.meaning-correct-lines{position:absolute;inset:0;width:100%;height:100%;z-index:3;pointer-events:none;overflow:visible}
.meaning-correct-path{fill:none;stroke:#16834b;stroke-width:7;stroke-linecap:round;filter:drop-shadow(0 2px 2px rgba(20,75,45,.2))}
.meaning-connection-teacher.show-answer .meaning-node{background:#fff!important;color:#28372f!important;border-color:#9bbda4!important}

/* 2.5: wider fixed cells, no orphaned Chinese characters or punctuation. */
.learning-summary-grid{width:min(1260px,98%)!important;grid-template-columns:1.08fr 1.42fr!important;gap:12px 14px!important}
.summary-module{padding:14px 18px!important;overflow:hidden}
.summary-module-1>div,.summary-module-3{white-space:nowrap!important}
.summary-module-1>div{font-size:clamp(21px,1.75cqw,31px)!important}
.summary-module-3{font-size:clamp(22px,1.82cqw,32px)!important}
.summary-module.knowledge{font-size:clamp(20px,1.62cqw,29px)!important;line-height:1.3!important;text-wrap:balance}
.summary-highlight{background:#d95f18!important;color:#fff!important;box-shadow:0 3px 0 #9f3d09;font-size:1.12em;white-space:nowrap!important}

/* 3.2: reserve all four card and answer areas before any statistic appears. */
.value-cumulative-list{
 height:24cqw!important;max-height:390px!important;grid-template-columns:repeat(2,minmax(0,1fr))!important;
 grid-template-rows:repeat(2,minmax(0,1fr))!important;align-items:stretch!important
}
.value-cumulative-item{height:100%!important;min-height:0!important;display:grid!important;grid-template-rows:4.2cqw minmax(0,1fr)!important;overflow:hidden!important}
.value-cumulative-item .value-stat-question{height:4.2cqw!important;min-height:58px!important;overflow:hidden!important}
.value-cumulative-item .value-answer-stat-grid,.value-stat-pending{height:100%!important;min-height:0!important;overflow:auto!important;align-content:center!important}
.value-cumulative-item.question-only .value-stat-pending{visibility:hidden!important}

@media(max-width:720px){
 .student-task .expression-tools{width:98vw!important;gap:6px!important}
 .student-task .expression-tools .token-group{padding:6px!important}
 .student-task .expression-tools .token-chip{width:min(100%,40px)!important}
 .student-task .expression-tools .word-token{width:100%!important;max-width:none!important}
}

/* Final 2.1 tool geometry: explicit placement wins over all earlier named grid areas. */
.student-task .expression-tools .group-words{grid-area:auto!important;grid-column:1/13!important;grid-row:1!important}
.student-task .expression-tools .group-operators{grid-area:auto!important;grid-column:13/21!important;grid-row:1!important}
.student-task .expression-tools .group-numbers{grid-area:auto!important;grid-column:1/8!important;grid-row:2!important}
.student-task .expression-tools .group-shapes{grid-area:auto!important;grid-column:8/13!important;grid-row:2!important}
.student-task .expression-tools .group-letters{grid-area:auto!important;grid-column:13/21!important;grid-row:2!important}
.student-task .expression-tools .token-group{grid-template-columns:1fr!important;grid-template-rows:1fr!important}
.student-task .expression-tools .token-row{display:grid!important;align-items:center!important;justify-content:center!important;gap:6px!important}
.student-task .expression-tools .group-words .token-row{grid-template-columns:repeat(2,minmax(0,1fr))!important}
.student-task .expression-tools .group-operators .token-row{grid-template-columns:repeat(5,minmax(0,1fr))!important}
.student-task .expression-tools .group-numbers .token-row{grid-template-columns:repeat(5,minmax(0,1fr))!important}
.student-task .expression-tools .group-shapes .token-row{grid-template-columns:repeat(4,minmax(0,1fr))!important}
.student-task .expression-tools .group-letters .token-row{grid-template-columns:repeat(6,minmax(0,1fr))!important}
.student-task .expression-tools .token-chip{
 width:100%!important;max-width:52px!important;height:auto!important;min-width:0!important;min-height:0!important;
 aspect-ratio:1!important;padding:0!important;display:grid!important;place-items:center!important;line-height:1!important
}
.student-task .expression-tools .word-token{
 width:100%!important;max-width:none!important;height:auto!important;aspect-ratio:5/1!important;
 white-space:nowrap!important;font-size:clamp(14px,2.1vw,18px)!important;padding:0 8px!important
}

/* Revision 5: larger 3.2 answer panels, ninth-step conclusion, and centered 2.1 work. */
.value-cumulative-list{height:29cqw!important;max-height:480px!important}
.value-cumulative-item{grid-template-rows:4.2cqw minmax(0,1fr)!important}
.value-cumulative-item .value-answer-stat-grid{
 overflow:hidden!important;align-content:flex-start!important;align-items:stretch!important;padding-bottom:.35cqw!important
}
.value-cumulative-item .value-answer-stat{min-height:4.3cqw!important;align-content:center!important}
.value-range-conclusion{
 width:92%;margin:.35cqw auto 0;padding:.7cqw 1.3cqw;border:3px solid #d76d27;border-radius:1cqw;
 background:#fff3df;text-align:center;color:#29382f;box-shadow:0 8px 20px rgba(108,63,27,.12)
}
.value-range-conclusion strong{display:block;font-size:clamp(24px,1.9cqw,38px);color:#a64618}
.value-range-conclusion p{margin:.25em 0 0;font-size:clamp(17px,1.15cqw,23px);font-weight:800}
.expression-share-answer{
 display:flex!important;align-items:center!important;justify-content:center!important;
 width:max-content!important;min-width:100%!important;height:100%!important;margin:0!important;padding:0 3cqw!important;
 font-size:clamp(30px,3.5cqw,60px)!important;text-align:center!important
}

/* New 4.2 exploration replaces the former eight-page discussion. */
.c-exploration-board{height:100%;display:grid;grid-template-rows:auto minmax(0,1fr) auto auto;gap:1cqw;align-items:center;padding:1cqw 3cqw}
.c-given{padding:1cqw 1.4cqw;border-radius:1cqw;background:#eef5ee;border:2px solid #afc8b4;text-align:center}
.c-given span{display:block;color:#397158;font-weight:900;font-size:clamp(15px,1cqw,20px)}
.c-given strong{display:block;margin-top:.2em;font-size:clamp(22px,1.65cqw,33px)}
.c-expression-stage{display:grid;place-items:center;align-content:center;gap:1.2cqw}
.c-symbol{font:950 clamp(86px,9cqw,150px)/1 "Cambria Math",serif;color:#2d654c}
.c-formula{font:950 clamp(58px,6cqw,105px)/1.1 "Cambria Math",serif;color:#243a30;animation:discoveryFade .24s ease-out both}
.c-formula i{display:inline-block;min-width:1.3em;border-bottom:.08em solid #d46f2b;font-style:normal}
.c-instruction{text-align:center;font-size:clamp(20px,1.4cqw,28px);font-weight:850;color:#85502c}
.c-statistics{width:92%;display:grid;grid-template-columns:1fr 1fr;gap:1cqw;margin:auto}
.c-statistics>div{min-height:10cqw;padding:1cqw;border:2px solid #d9c8aa;border-radius:1cqw;background:#fffaf0}
.c-statistics h3{text-align:center;font-size:clamp(20px,1.4cqw,28px);margin:0 0 .7cqw}
.c-statistics span{display:inline-flex;gap:.4em;margin:.3cqw;padding:.45cqw .7cqw;border-radius:999px;background:#e8f1e9;font-size:clamp(16px,1.05cqw,21px)}
.student-worksheet-line select{min-width:180px;padding:12px 14px;border:2px solid #9db1a3;border-radius:12px;background:#fff;font:800 18px/1.2 inherit;color:#26382f}


/* ===== Rehearsal correction · round 5 ===== */

/* 2.1: when a long sampled answer overflows, keep its initial viewport centered. */
.expression-share-zone{scroll-behavior:smooth}
.expression-share-answer{flex:0 0 auto!important}

/* 4.1 teacher: enlarge the known-condition card and reveal one horizontal expression from left to right. */
.c-given{
 width:min(92%,1180px)!important;margin:0 auto!important;
 padding:1.35cqw 1.8cqw!important;border-width:3px!important;border-radius:1.25cqw!important
}
.c-given span{font-size:clamp(22px,1.45cqw,29px)!important;letter-spacing:.08em}
.c-given strong{font-size:clamp(31px,2.35cqw,46px)!important;line-height:1.3!important}
.c-expression-stage{min-height:20cqw!important}
.c-formula-flow{
 min-width:60%;display:flex;align-items:center;justify-content:center;gap:1.35cqw;
 white-space:nowrap;font-family:"Cambria Math","Microsoft YaHei",sans-serif;color:#243a30
}
.c-flow-c,.c-flow-equals,.c-flow-tail{
 display:inline-flex;align-items:center;justify-content:center;
 font:950 clamp(82px,8.2cqw,142px)/1 "Cambria Math","Microsoft YaHei",sans-serif
}
.c-flow-equals{animation:cFlowReveal .26s ease-out both}
.c-flow-tail{animation:cFlowReveal .32s .18s ease-out both}
.c-flow-tail i{
 display:inline-block;width:1.25em;height:.78em;margin:0 .08em;
 border-bottom:.075em solid #d46f2b
}
@keyframes cFlowReveal{from{opacity:0;transform:translateX(-14px)}to{opacity:1;transform:none}}
.c-instruction{font-size:clamp(24px,1.75cqw,34px)!important}

/* 4.1 student: larger answer typography and compact parentheses around the selected letter. */
.c-identity-student>h1{font-size:clamp(38px,5.6vw,58px)!important}
.c-identity-student>.prompt{font-size:clamp(24px,3.2vw,34px)!important;line-height:1.5!important}
.c-identity-student .student-worksheet-section{padding:24px 28px!important}
.c-identity-student .student-worksheet-section h2{font-size:clamp(30px,4vw,42px)!important}
.c-identity-student .student-worksheet-line{
 font-size:clamp(25px,3.2vw,34px)!important;font-weight:900!important;
 justify-content:start!important;gap:4px!important
}
.c-identity-student .student-worksheet-line select{
 font-size:clamp(23px,3vw,31px)!important;font-weight:900!important;
 padding:10px 12px!important;min-height:58px
}
.c-identity-student .worksheet-item-base_letter{
 grid-template-columns:max-content 128px max-content!important;column-gap:3px!important
}
.c-identity-student .worksheet-item-base_letter select{
 width:128px!important;min-width:128px!important;max-width:128px!important
}
.c-identity-student .worksheet-item-identity{
 grid-template-columns:max-content minmax(230px,300px) max-content!important;column-gap:10px!important
}
.c-identity-student .worksheet-item-identity select{width:100%!important;min-width:230px!important}

/* 4.1 3/3: make grouped answer statistics readable from the projection screen. */
.c-statistics{width:96%!important;gap:1.4cqw!important}
.c-statistics>div{min-height:12cqw!important;padding:1.25cqw 1.4cqw!important;border-width:3px!important}
.c-statistics h3{font-size:clamp(27px,2cqw,39px)!important;margin:0 0 .9cqw!important}
.c-statistics span{
 margin:.38cqw!important;padding:.58cqw .9cqw!important;
 font-size:clamp(22px,1.55cqw,31px)!important;font-weight:850!important
}
.c-statistics span b{font-size:1.08em}


/* ===== Rehearsal correction · round 6 ===== */

/* Activity-wide school logo: transparent PNG sits on a white circular plate above the lesson UI. */
.school-logo-overlay{
 position:fixed;left:18px;top:66px;z-index:70;
 width:clamp(86px,7.2vw,128px);height:clamp(86px,7.2vw,128px);
 display:grid;place-items:center;padding:10px;box-sizing:border-box;
 border-radius:50%;background:#fff;
 border:1px solid rgba(49,80,63,.12);
 box-shadow:0 12px 34px rgba(44,66,54,.16);
 pointer-events:none;overflow:hidden
}
.school-logo-overlay img{
 display:block;width:100%;height:100%;object-fit:contain;object-position:center
}
body.presentation-mode .school-logo-overlay{top:62px}
body.phone-classroom .school-logo-overlay{
 left:8px;top:58px;width:64px;height:64px;padding:6px
}


/* ===== Rehearsal correction · round 7 ===== */
.representative-card.is-empty{min-height:10.5cqw}
.representative-card.is-empty::before,.representative-card.is-empty::after{content:none!important}

.c-transform-teacher{width:94%;margin:1.1cqw auto 0;text-align:center}
.c-transform-teacher>h2,.c-transform-results>h2{font-size:clamp(30px,2.35cqw,46px)!important;margin:0 0 1.2cqw}
.c-transform-branches{display:grid;grid-template-columns:1fr 1fr;gap:1.4cqw}
.c-transform-branches>div{min-height:12cqw;padding:1.25cqw 1.5cqw;border:3px solid rgba(65,105,87,.16);border-radius:1.3cqw;background:rgba(255,255,255,.92);display:grid;align-content:center;gap:.7cqw}
.c-transform-branches small{font-size:clamp(20px,1.35cqw,27px);font-weight:850;color:#6a786f}
.c-transform-branches strong{font:950 clamp(43px,3.8cqw,70px)/1 "Cambria Math","Microsoft YaHei",sans-serif;color:#274e3c}
.c-transform-branches p{font-size:clamp(25px,1.8cqw,35px)!important;font-weight:850;margin:0}
.c-transform-results{width:96%;margin:0 auto}
.c-transform-student{max-width:1050px!important}
.c-transform-student-context{display:grid;gap:18px;margin:6px 0 24px}
.c-transform-known{padding:20px 24px;border:2px solid rgba(65,105,87,.18);border-radius:22px;background:#fffdf7}
.c-transform-known>strong{display:block;font-size:22px;color:#416957;margin-bottom:8px}
.c-transform-known p{font-size:clamp(24px,3vw,34px)!important;line-height:1.55!important;font-weight:760;margin:0}
.c-transform-given{text-align:center;font:950 clamp(56px,8vw,92px)/1.05 "Cambria Math","Microsoft YaHei",sans-serif;color:#274e3c;padding:12px 0}
.c-transform-student-context h2{text-align:center;font-size:clamp(30px,4vw,44px)!important;margin:0}
.c-transform-form{display:grid;gap:18px}
.c-transform-answer{display:flex;align-items:center;justify-content:center;gap:3px;font:950 clamp(44px,6vw,72px)/1 "Cambria Math","Microsoft YaHei",sans-serif}
.c-transform-answer input{width:min(42vw,330px)!important;min-width:210px;font-size:clamp(30px,4vw,48px)!important;text-align:center;font-weight:900;padding:12px 14px!important;border-radius:16px}

/* Stable teacher header across control/presentation modes. */
.teacher-top{
 min-height:58px!important;padding:8px 14px!important;gap:8px!important;flex-wrap:nowrap!important;
 overflow-x:auto;scrollbar-width:none
}
.teacher-top::-webkit-scrollbar{display:none}
.teacher-top .brand{flex:0 0 auto;white-space:nowrap}
.teacher-top button,.teacher-top .btn,.teacher-top a.btn{
 min-height:38px!important;padding:8px 11px!important;border-radius:10px!important;white-space:nowrap!important
}
body.presentation-mode .teacher-top{min-height:58px!important}
@media(max-width:720px){
 .teacher-top{min-height:52px!important;padding:6px 8px!important}
 .teacher-top button,.teacher-top .btn,.teacher-top a.btn{min-height:34px!important;padding:6px 9px!important;font-size:12px!important}
}

/* ===== Classroom V8 blue-white runtime ===== */
body.classroom-entry-page{background:radial-gradient(circle at 8% 10%,rgba(73,174,226,.13),transparent 28rem),radial-gradient(circle at 92% 88%,rgba(76,189,176,.10),transparent 28rem),#f4faff!important}
.classroom-runtime-brand{display:inline-flex;align-items:center;gap:9px;margin-right:auto;text-decoration:none;color:#164c6a}
.classroom-runtime-brand img{width:40px;height:40px;border-radius:11px;object-fit:cover;box-shadow:0 6px 18px rgba(21,91,130,.12)}
.classroom-runtime-brand span{font-family:"WML Source Han Sans","Source Han Sans SC",sans-serif;font-weight:650;font-size:15px}
.teacher-top,.student-top{background:rgba(248,252,255,.96)!important;border-bottom-color:#d3e6f1!important}
.control-rail{background:#f8fcff!important;border-left-color:#d3e6f1!important}
.task-card,.result-box,.character-card,.metric,.expression-card,.student-task{background:#fff!important;border-color:#d3e6f1!important}
.stage-tab.active,.relation-banner{background:#168fd3!important;border-color:#168fd3!important}
.join-students-btn{background:#168fd3!important;border-color:#168fd3!important}
.student-brand img{width:38px;height:38px;border-radius:10px;object-fit:cover}.student-brand span{font-weight:650;color:#164c6a}