:root{--ink:#263d39;--muted:#6f7b75;--green:#244d46;--paper:#f7f8f2;--line:#e0e5dc;--sage:#e6eddf;--peach:#f6e5d8;--blue:#e2ecf2;--lavender:#ebe6f3}*{box-sizing:border-box}body{margin:0;background:var(--paper);font:16px/1.65 system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;color:var(--ink)}button,input,select{font:inherit}button,a,select,input{ -webkit-tap-highlight-color:transparent}button{cursor:pointer}button:disabled{opacity:.55;cursor:default}a{color:inherit;text-decoration:none}button:focus-visible,a:focus-visible,input:focus-visible,select:focus-visible{outline:3px solid #bd7833;outline-offset:4px}h1,h2,h3,p{margin-top:0}h1{font-size:clamp(28px,3vw,43px);line-height:1.22;letter-spacing:-1px}h2{font-size:25px;line-height:1.35}h3{font-size:19px;line-height:1.4}.sidebar{position:fixed;inset:0 auto 0 0;width:248px;background:#fffef9;border-right:1px solid var(--line);padding:34px 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var(--line);background:white;border-radius:8px;color:var(--ink);font-size:13px}.local-note{font-size:10px;color:var(--muted);margin-top:10px}.workspace{margin-left:248px}.topbar{height:83px;border-bottom:1px solid var(--line);display:flex;justify-content:space-between;align-items:center;padding:0 42px;font-size:12px;background:#fffef988}.divider{margin:0 13px;color:#a3ada6}.pill{font-size:10px;text-transform:uppercase;letter-spacing:1px;padding:5px 11px;border:1px solid #cdd8ca;border-radius:30px;white-space:nowrap}main{padding:36px 42px 45px;max-width:1480px;margin:auto;min-height:80vh}main:focus{outline:none}.eyebrow{font-size:11px;letter-spacing:2px;color:var(--muted);font-weight:650;text-transform:uppercase;margin-bottom:12px}.hero{display:grid;grid-template-columns:1.5fr 1fr;gap:20px;align-items:center;background:#e7eddf;border:1px solid #dce4d3;border-radius:22px;padding:32px 38px;margin-bottom:27px;overflow:hidden}.hero p{font-size:14px;max-width:470px;color:#5c6e60;margin-bottom:23px}.hero h1{margin-bottom:14px}.hero-art{position:relative;height:215px;display:flex;align-items:center;justify-content:center;gap:12px;transform:rotate(-7deg)}.art-card{width:110px;height:145px;border:1px solid #c7cdb9;border-radius:12px;background:#fffdf3;box-shadow:5px 9px 0 #c8d2bd80;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:9px}.art-card:nth-child(2){background:#f1cf99;transform:rotate(16deg) translateY(24px)}.art-card b{font-size:54px;font-weight:500}.art-card span{font-size:10px;letter-spacing:2px}.art-spark{position:absolute;top:0;right:22px;font-size:45px;color:#6d8657}.primary,.secondary,.text-button{border:0;border-radius:9px;padding:12px 19px;font-size:14px;font-weight:600;display:inline-flex;align-items:center;justify-content:center;gap:12px;min-height:46px}.primary{background:var(--green);color:#fff}.primary:hover{background:#316157}.secondary{background:white;border:1px solid var(--line);color:var(--ink)}.text-button{background:transparent;color:var(--green);padding:8px}.stats{display:grid;grid-template-columns:repeat(3,1fr);gap:14px;margin-bottom:32px}.stat{background:#fffef9;border:1px solid var(--line);border-radius:12px;padding:17px 20px;display:flex;gap:16px;align-items:center}.stat b{font-size:28px;font-weight:550}.stat span{font-size:12px;color:var(--muted)}.section-head{display:flex;justify-content:space-between;align-items:center;margin:22px 0 16px}.section-head h2{margin:0;font-size:22px}.section-head p{margin:4px 0;font-size:13px;color:var(--muted)}.unit-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:18px}.unit-card{background:#fffefb;border:1px solid var(--line);border-radius:16px;overflow:hidden;transition:transform .2s}.unit-card:hover{transform:translateY(-3px)}.unit-top{padding:17px 23px;display:flex;align-items:center;justify-content:space-between}.sage{background:var(--sage)}.peach{background:var(--peach)}.blue{background:var(--blue)}.lavender{background:var(--lavender)}.unit-number{font-size:10px;font-weight:700;letter-spacing:2px}.unit-symbol{font-size:38px;line-height:1}.unit-body{padding:21px 23px}.unit-body h3{margin-bottom:5px}.unit-body p{font-size:12px;color:var(--muted);margin-bottom:20px}.unit-meta{display:flex;justify-content:space-between;align-items:center;font-size:11px;color:var(--muted)}progress{appearance:none;width:100%;height:5px;border:0;border-radius:10px;overflow:hidden;margin:15px 0 4px;background:#e8ece4}progress::-webkit-progress-bar{background:#e8ece4}progress::-webkit-progress-value{background:#718e62}progress::-moz-progress-bar{background:#718e62}.bottom-note{display:flex;gap:15px;align-items:center;margin-top:25px;padding:18px 22px;border:1px dashed #ccd5c5;border-radius:12px;font-size:12px;color:var(--muted)}.bottom-note strong{color:var(--ink)}footer{border-top:1px solid var(--line);padding:18px 42px;font-size:10px;color:var(--muted);display:flex;justify-content:space-between;gap:12px}footer button{border:0;background:none;color:var(--green);font-size:11px;cursor:pointer}.back{display:inline-block;font-size:13px;margin-bottom:18px;color:var(--muted)}.unit-banner{border-radius:16px;padding:25px 30px;margin-bottom:24px}.unit-banner h1{font-size:32px;margin:8px 0}.unit-banner p{font-size:14px;margin:0;color:#586960}.lesson-list{display:grid;gap:12px}.lesson-row{display:flex;align-items:center;gap:18px;border:1px solid var(--line);background:#fffefa;padding:19px 22px;border-radius:12px}.lesson-row .index{display:grid;place-items:center;width:43px;height:43px;flex:none;background:var(--sage);border-radius:12px;font-size:14px}.lesson-row div:nth-child(2){flex:1}.lesson-row h3{margin:0 0 5px;font-size:16px}.lesson-row p{font-size:12px;margin:0;color:var(--muted)}.lesson-layout{display:grid;grid-template-columns:minmax(0,1fr) 290px;gap:23px;align-items:start}.panel{background:#fffefa;border:1px solid var(--line);border-radius:15px;padding:25px;margin-bottom:20px}.panel h2{font-size:21px}.step-index{font-size:11px;color:var(--muted);margin-bottom:12px}.lesson-layout p{font-size:15px}.step-controls{display:flex;justify-content:space-between;gap:12px;margin-top:24px}.demo{background:#edf1e7;border-radius:12px;padding:19px;margin:18px 0}.demo label{font-size:12px;display:block;margin-bottom:10px}.demo input[type=range]{width:100%;accent-color:var(--green);min-height:40px}.place-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:7px;margin:15px 0}.place-grid>div{background:#fffefa;border:1px solid #d6dfcc;border-radius:10px;padding:12px 2px;text-align:center}.place-grid b{display:block;font-size:26px}.place-grid span{font-size:10px}.demo output{display:block;font-size:18px;font-weight:600;text-align:center;margin-top:12px}.demo svg{display:block;width:100%;max-height:200px}.question{border-bottom:1px solid var(--line);padding:20px 0}.question:first-of-type{padding-top:5px}.question:last-child{border:0}.question h3{font-size:15px;margin-bottom:12px}.answer-form{display:flex;gap:8px;flex-wrap:wrap}.answer-form input{width:170px;min-height:46px;padding:9px 12px;border:1px solid #bac8b5;border-radius:8px;background:#fff}.choice{border:1px solid #cbd5c4;background:#fff;border-radius:9px;padding:10px 18px;min-height:46px}.choice.selected{background:var(--green);color:white;border-color:var(--green)}.feedback{font-size:13px;margin:12px 0 0;border-radius:8px;padding:10px 12px}.feedback.good{background:#e3efdf;color:#2b5732}.feedback.retry{background:#fff0d7;color:#71501c}.hint{font-size:12px;color:var(--muted)}.lesson-tabs{display:flex;gap:8px;margin-bottom:18px;flex-wrap:wrap}.lesson-tabs button{border:1px solid var(--line);border-radius:9px;padding:10px 16px;background:white;font-size:13px}.lesson-tabs button.active{background:var(--green);color:white}.notebook{position:sticky;top:20px}.notebook h2{font-size:17px}.notebook p{font-size:11px;color:var(--muted)}.notebook canvas{display:block;width:100%;height:310px;background-color:#fffefa;background-image:linear-gradient(#cfdccd65 1px,transparent 1px),linear-gradient(90deg,#cfdccd65 1px,transparent 1px);background-size:20px 20px;border:1px solid #dce2d5;border-radius:10px;touch-action:none}.tools{display:flex;flex-wrap:wrap;gap:6px;margin:10px 0}.tools button{font-size:11px;min-height:40px;padding:6px 10px}.tools .chosen{background:var(--sage);border-color:#739368}.notebook label{font-size:11px;display:flex;gap:5px;align-items:center}.saved{font-size:10px;color:var(--muted);min-height:20px}.notice{background:#fff3df;border:1px solid #e7d7b5;border-radius:12px;padding:16px 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p{font-size:14px}.skip{position:fixed;top:-100px;z-index:20;background:white;padding:15px}.skip:focus{top:0}.sr-only{position:absolute;width:1px;height:1px;overflow:hidden;clip-path:inset(50%)}.reset-row{margin-top:30px;font-size:12px;color:var(--muted)}.reset-row button{margin-left:10px}.chip{font-size:10px;background:var(--sage);border-radius:15px;padding:3px 9px}.quiz-submit{margin-top:22px}.quiz-result{border-top:1px solid var(--line);margin-top:25px;padding-top:22px}.geometry-key{display:flex;gap:12px;font-size:11px;flex-wrap:wrap;color:var(--muted)}
@media(min-width:1450px){.hero{padding:40px 48px}.hero-art{height:240px}.unit-grid{gap:23px}.unit-body{padding:25px}}
@media(max-width:1150px){.sidebar{width:210px;padding:28px 17px}.workspace{margin-left:210px}main{padding:28px 25px}.topbar{padding:0 25px}.hero{padding:25px}.hero-art{gap:8px}.art-card{width:85px;height:120px}.art-card b{font-size:43px}.lesson-layout{grid-template-columns:minmax(0,1fr) 250px}.panel{padding:20px}.stats{gap:10px}.stat{padding:13px;gap:10px}}
@media(max-width:900px){.sidebar{position:static;width:100%;padding:15px 22px;display:grid;grid-template-columns:auto 1fr;gap:14px;align-items:center;border-right:0;border-bottom:1px solid var(--line)}.brand{font-size:28px}.brandmark{width:38px;height:42px;font-size:36px}.brand small{display:none}.class-label,.sidebar-note,.role-label,.local-note{display:none}nav{display:flex;justify-content:flex-end;gap:5px}nav a{padding:9px;font-size:12px;gap:6px}.sidebar select{grid-column:1/-1;max-width:240px;justify-self:end}.workspace{margin:0}.topbar{height:59px}.lesson-layout{grid-template-columns:minmax(0,1fr) 260px}.hero h1{font-size:32px}.hero-art{height:180px}.stat span{font-size:11px}}
@media(max-width:650px){main{padding:23px 16px}.sidebar{padding:12px 16px}.sidebar nav a{font-size:11px;padding:8px 5px}.sidebar nav a span{max-width:75px;line-height:1.3}.topbar{padding:0 16px;font-size:10px}.divider{margin:0 5px}.pill{font-size:8px;padding:4px 7px}.hero{grid-template-columns:1fr;padding:25px}.hero-art{display:none}.stats{grid-template-columns:repeat(3,1fr);gap:7px}.stat{display:block;padding:10px}.stat b{display:block;font-size:23px}.stat span{font-size:10px}.unit-grid{grid-template-columns:1fr}.lesson-layout{grid-template-columns:1fr}.notebook{position:static}.notebook canvas{height:330px}.lesson-row{gap:10px;padding:15px}.lesson-row .index{width:33px;height:36px}.lesson-row h3{font-size:14px}.lesson-row .primary{padding:9px;font-size:11px}.lesson-row p{font-size:11px}.unit-banner{padding:22px}.unit-banner h1{font-size:27px}footer{padding:18px 16px;flex-direction:column}.report{font-size:11px}.section-head{gap:12px}.section-head h2{font-size:20px}}
.account-form{display:grid;gap:16px}.account-form label{display:grid;gap:6px;font-size:13px}.account-form input{min-height:46px;padding:10px 12px;border:1px solid #b7c8b3;border-radius:8px;min-width:0;width:100%}.auth-panel{max-width:580px}.form-status,#account-error{font-size:13px;color:#8c3f24;overflow-wrap:anywhere}#account-area{font-size:12px;max-height:38vh;overflow:auto}#account-area>button{margin-top:10px}#account-area .tools button{font-size:10px;padding:6px 9px}.account-form select{font-size:14px}[hidden]{display:none!important}@media(max-width:900px){#account-area{grid-column:1/-1;max-height:none;display:flex;gap:12px;align-items:center;flex-wrap:wrap}#account-area select{max-width:200px}#account-area .tools{margin:0}}@media(prefers-reduced-motion:reduce){*{scroll-behavior:auto!important;transition:none!important}}
.authenticated .sidebar-note{display:none}.authenticated #account-area{max-height:55vh}.authenticated .role-label{margin-top:auto;padding-top:25px}@media(max-width:900px){.authenticated #account-area{max-height:none}}