.choices{display:flex;gap:16px;flex-wrap:wrap;margin:18px 0}.choices .ui{font-size:30px;padding:12px 22px}.feedback{min-height:66px;font-size:28px;color:#526079;margin:18px 0}.feedback.good{color:#087663}.feedback.bad{color:#b45309}.choices button.selected{background:#e0f2fe;border-color:#2563eb}.result{padding:18px 24px;background:var(--cs);border-radius:16px;margin-top:18px;min-height:90px;font-size:36px}.barrow{display:flex;align-items:center;gap:25px;margin:22px 0}.barrow>span{width:100px;flex-shrink:0}.measure{height:62px;background:#2563eb;color:white;text-align:center;border-radius:10px;transition:width .5s;white-space:nowrap}.measure.pink{background:#c92c70}.whole{display:flex;width:1040px;height:70px;background:#b45309;color:white;border-radius:12px;overflow:hidden}.whole i{font-style:normal;text-align:center;flex:1}.whole i:first-child{background:#2563eb;flex:none}.grid20{display:grid;grid-template-columns:repeat(10,1fr);gap:9px;margin:24px 0}.grid20 span{height:88px;border:2px solid #ccd4df;background:#eef2f7;border-radius:10px;display:grid;place-items:center;font-size:28px}.grid20 .first{background:#c92c70;color:white}.grid20 .second{background:#2563eb;color:white}.agenda p{padding:10px 20px;border-bottom:1px solid #dbe2ea}.agenda b{display:inline-block;width:150px;color:var(--c)}.source{font-size:29px}.source p{margin-bottom:22px}#modeSwitch{position:fixed;right:18px;top:14px;z-index:40;border:1px solid #64748b;color:white;background:#172033;padding:9px 14px;border-radius:9px;cursor:pointer;font:14px system-ui}.answer input{width:170px}.steps p{margin-bottom:16px}.quiz .q{font-family:inherit;font-size:37px}.slide h2{margin-bottom:26px}
/* Student projection: questions and examples only. Teacher tools appear with N. */
#hint,#modeSwitch{display:none}
#notebox.on ~ #modeSwitch{display:block}
#notebox a{color:#075985;text-decoration:underline}
.lead{font-size:48px;margin:36px 0}.think{font-size:34px;margin:24px 0;color:#344054;line-height:1.6}.review p{padding:16px 0;border-bottom:1px solid #e4e7ec;font-size:32px}.review b{color:var(--c)}
.grid20{display:block;margin:24px 0}.bookFirst{display:grid;grid-template-columns:repeat(5,1fr);width:calc((100% - 64px)/3);gap:7px;margin-bottom:26px}.bookRest{display:grid;grid-template-columns:repeat(5,1fr);gap:16px}.bookGroup{display:grid;grid-template-columns:repeat(3,1fr);gap:7px;padding:7px;border:2px solid transparent;border-radius:13px}.bookFirst{padding:9px}.grid20 span{height:74px;font-size:25px}.grid20.grouped .bookGroup{border:2px dashed #94a3b8}.barrow>span{width:115px}.choices .base{font-size:26px}.result{font-size:31px}.slide h2{font-size:50px}.steps p{font-size:36px}.q{font-size:38px}
.bookFirst{width:max-content;grid-template-columns:repeat(5,76px)}.bookRest{grid-template-columns:repeat(5,max-content)}.bookGroup{grid-template-columns:repeat(3,76px)}
.appleModel{margin:24px 0}.appleRow{display:flex;gap:24px;align-items:center;margin:24px 0}.appleRow>b{width:90px}.appleCells{display:flex;gap:7px}.appleCells i{display:block;width:95px;height:66px;border:2px solid #94a3b8;border-radius:8px;background:#eef2f6}.appleCells .taken{background:#2563eb;border-color:#2563eb}.appleRow>span{font-size:28px;color:#475569}.relation{display:flex;align-items:center;gap:28px;margin:40px 0}.relation span{padding:20px 45px;background:var(--cs);border-radius:14px}.relation b{font-size:30px;color:var(--c)}.schoolRow{display:flex;gap:20px;align-items:center;margin:30px 0}.schoolRow>b{width:95px;flex-shrink:0}.schoolCells{display:grid;grid-template-columns:repeat(50,20px);gap:4px}.schoolCells span{height:60px;border:1px solid #a8b4c6;background:#f0f3f8;border-radius:3px}.schoolCells span.five{border-right:3px solid #607189}.schoolCells span.girl{background:#c92c70;border-color:#a7235d}.schoolCells span.boy{background:#2563eb;border-color:#1749ac}.school{font-size:25px!important}