.lab-entry{display:flex;align-items:center;gap:14px;width:100%;padding:16px 20px;margin:16px 0 22px;background:#e4f1f8;border:1px solid #c4dfe9;border-radius:18px;text-align:left}.lab-entry strong,.lab-entry small{display:block}.lab-entry .arrow{margin-left:auto}.lab-catalog{display:grid;gap:14px}.lab-item{display:flex;gap:16px;text-align:left;width:100%;align-items:start}.lab-item span{min-width:0}.lab-item p{font-size:12px;margin-top:8px}.lab-item h3{font-size:17px}#laboratory{position:fixed;inset:0;z-index:60;background:var(--bg);overflow:auto}#laboratory[hidden]{display:none}.lab-body{max-width:1400px;margin:auto;padding:20px;display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1fr);gap:20px}.lab-model{position:sticky;top:0;align-self:start}.lab-model h2{font-size:18px}#lab-canvas{display:block;width:100%;height:330px;touch-action:none;border-radius:12px;margin:12px 0}.lab-controls{display:flex;flex-wrap:wrap;align-items:center;gap:10px}.lab-controls label{display:flex;align-items:center;gap:6px}.lab-controls button{background:#e4f1f8;border-radius:8px;padding:4px 12px}#lab-caption{font-size:13px;margin:10px 0}.lab-reading p,.lab-reading li{margin:12px 0}.lab-option{display:flex;gap:8px;margin:10px 0;padding:10px;background:#f1f6f9;border-radius:8px}.lab-reading [data-lab-lesson]{display:block;text-align:left;border-bottom:1px solid var(--line);width:100%}@media(max-width:650px){.lab-body{display:block;padding:10px}.lab-model{position:relative;margin-bottom:14px}#lab-canvas{height:210px}.lab-controls{font-size:12px}.lab-body .card{padding:14px}.lab-entry{padding:12px 16px}.lab-entry strong{font-size:17px}}@media(min-width:651px) and (max-height:500px){.lab-body{padding:8px;gap:10px}#lab-canvas{height:160px}.lab-model{position:relative}.lab-body .card{padding:12px}.lab-controls{font-size:12px}}.hero-line{display:block;white-space:nowrap}.continue>div{min-width:0}.continue h3{max-width:560px}@media(max-width:650px){.continue{flex-wrap:wrap}.continue>div{width:100%}.continue .primary{margin-left:auto;margin-top:3px}.hero{min-height:250px}}:root{--navy:#073e64;--blue:#096bba;--cyan:#20bed1;--orange:#f18a34;--ink:#15354b;--muted:#627b8c;--bg:#f1f6f9;--line:#dfebf1}*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--ink);font:15px/1.55 'Noto Sans CJK SC','Microsoft YaHei',sans-serif}button,input,select{font:inherit}button,a{-webkit-tap-highlight-color:transparent}button{cursor:pointer;border:0;color:inherit;background:none}button:focus-visible,a:focus-visible,input:focus-visible,select:focus-visible{outline:3px solid var(--orange);outline-offset:3px}a{color:inherit;text-decoration:none}button{min-height:44px}#shell{max-width:1100px;margin:auto;padding:0 28px 110px}.topbar{height:88px;display:flex;align-items:center;justify-content:space-between;gap:10px}.brand{display:flex;align-items:center;gap:10px;font-weight:850;font-size:24px;letter-spacing:2px}.brand img{width:45px;height:45px;border-radius:13px}.brand-sub{display:block;font-size:10px;letter-spacing:1px;color:var(--muted);font-weight:500}.offline{font-size:11px;color:#477587;border:1px solid #c9e0e7;border-radius:30px;padding:5px 9px;white-space:nowrap}h1,h2,h3,p{margin:0}h2{font-size:21px;letter-spacing:.5px}small,.muted{color:var(--muted)}.eyebrow{font-size:11px;font-weight:700;letter-spacing:2px}.hero{background:var(--navy);color:white;position:relative;border-radius:26px;padding:34px;overflow:hidden;min-height:265px;display:flex;align-items:center}.hero:before{content:'';position:absolute;width:320px;height:320px;border:1px solid #ffffff18;border-radius:50%;right:-85px;top:-170px;box-shadow:0 0 0 38px #ffffff05,0 0 0 76px #ffffff05}.hero-copy{width:62%;z-index:1}.hero .eyebrow{color:#83e4e9}.hero h1{font-family:'Noto Serif CJK SC','Songti SC',serif;font-size:38px;line-height:1.35;letter-spacing:2px;margin:10px 0}.hero p{color:#c1dde9;font-size:13px}.hero-tag{margin-top:20px;display:inline-block;border-left:3px solid var(--orange);padding-left:10px;font-size:11px}.mascot-card{position:absolute;right:24px;top:32px;width:190px;height:200px;border-radius:50% 50% 22px 22px;background:white;transform:rotate(3deg);box-shadow:0 12px 0 #012f4b55;overflow:hidden}.mascot-card img{width:100%;height:100%;object-fit:contain}.continue{background:white;border:1px solid var(--line);margin-top:-2px;position:relative;border-radius:22px;padding:20px 24px;display:flex;justify-content:space-between;gap:14px;align-items:center;box-shadow:0 8px 20px #244f6410}.continue small{font-size:11px}.continue h3{font-size:20px;margin:4px 0}.primary{background:var(--blue);color:white;border-radius:13px;padding:10px 18px;font-weight:700;white-space:nowrap}.arrow{font-size:24px}.section-head{display:flex;align-items:center;justify-content:space-between;margin:28px 0 13px;gap:10px}.section-head button{color:var(--blue);font-size:12px}.quick-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:12px;margin:20px 0}.quick{background:white;border:1px solid var(--line);border-radius:19px;padding:18px 6px;font-weight:700;font-size:14px;text-align:center}.icon{display:block;width:24px;height:24px;object-fit:contain}.quick .icon{margin:0 auto 10px;width:30px;height:30px;filter:invert(30%) sepia(70%) saturate(1100%) hue-rotate(166deg)}.quick:nth-child(3) .icon{filter:invert(60%) sepia(70%) saturate(750%) hue-rotate(345deg)}.card{border:1px solid var(--line);border-radius:21px;padding:22px;background:white}.check-head{display:flex;align-items:center;justify-content:space-between}.check-head h3{font-size:17px}.badge{background:#e5f6f5;color:#087f82;border-radius:24px;padding:4px 10px;font-size:11px;font-weight:700}.week{display:grid;grid-template-columns:repeat(7,1fr);gap:6px;text-align:center;margin-top:18px}.day{display:flex;align-items:center;flex-direction:column;font-size:11px;color:var(--muted)}.day b{display:grid;place-items:center;width:33px;height:33px;border-radius:50%;background:#f1f5f8;color:#73909f;margin-top:8px;font-family:monospace;font-size:13px}.day.checked b{color:white;background:var(--blue)}.day.today b{outline:2px solid var(--orange);outline-offset:3px}.count{font-size:12px;margin-top:17px;color:var(--muted)}.count strong{color:var(--navy);font-family:monospace;font-size:20px;margin:0 4px}.chapter-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:12px}.chapter{background:white;border:1px solid var(--line);border-radius:19px;padding:19px;text-align:left;width:100%;display:flex;align-items:center;gap:15px}.chapter .num{font-family:monospace;font-size:27px;color:#0d8ca6;min-width:43px;border-right:1px solid var(--line)}.chapter h3{font-size:15px}.chapter small{font-size:11px}.chapter .arrow{margin-left:auto;color:var(--blue)}.books-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:15px}.book{display:flex;align-items:center;gap:17px;background:white;border:1px solid var(--line);border-radius:19px;padding:18px;text-align:left;min-width:0}.cover{width:84px;height:113px;object-fit:cover;box-shadow:2px 4px 9px #173e5025;border-radius:3px}.book h3{font-size:15px}.book small{font-size:11px}.book em{display:block;font-style:normal;color:var(--blue);font-size:12px;margin-top:9px}.bottom{position:fixed;bottom:0;left:50%;transform:translateX(-50%);width:min(100%,1044px);background:#ffffffef;border:1px solid var(--line);border-bottom:0;border-radius:22px 22px 0 0;display:grid;grid-template-columns:repeat(4,1fr);z-index:20;padding:9px 6px max(9px,env(safe-area-inset-bottom));backdrop-filter:blur(12px)}.bottom button{font-size:11px;color:var(--muted);display:flex;flex-direction:column;align-items:center;gap:4px}.bottom .icon{width:21px;height:21px;opacity:.5}.bottom button[aria-current=page]{color:var(--blue);font-weight:800}.bottom button[aria-current=page] .icon{opacity:1;filter:invert(29%) sepia(83%) saturate(1052%) hue-rotate(174deg)}.page-title{margin:15px 0 20px}.page-title h1{font-size:29px}.search{width:100%;background:white;border:1px solid #ccdee8;border-radius:14px;padding:13px;margin-bottom:16px}.lesson-row{width:100%;border-bottom:1px solid var(--line);padding:15px 2px;text-align:left;display:flex;gap:14px;align-items:center}.lesson-row span:first-child{font:14px monospace;color:#5d98b6}.lesson-row strong{font-size:14px}.lesson-row small{display:block;font-size:11px}.lesson-row .arrow{margin-left:auto}.course-group{margin-bottom:20px}.course-group h2{font-size:17px;margin-bottom:7px}.mine-head{display:flex;align-items:center;gap:18px}.mine-head img{width:90px;border-radius:20px}.stack{display:grid;gap:12px;margin:20px 0}.stack button{border:1px solid var(--line);background:white;border-radius:15px;padding:13px 16px;text-align:left}.readerbar{height:58px;background:white;border-bottom:1px solid var(--line);display:flex;align-items:center;justify-content:space-between;gap:8px;padding:6px 12px;flex-shrink:0}.readerbar b{font-size:13px}.readerbar button{color:var(--blue);font-size:13px}#classroom,#reader{position:fixed;inset:0;z-index:40;background:var(--bg);display:flex;flex-direction:column}#classroom[hidden],#reader[hidden]{display:none}iframe{border:0;width:100%;flex:1;min-height:0;background:white}#notice{position:fixed;z-index:100;bottom:100px;left:50%;transform:translateX(-50%);border-radius:13px;background:#062f49;color:white;max-width:90%;padding:12px 18px;font-size:13px;display:none}.tiny-note{font-size:12px;color:var(--muted);line-height:1.8;margin:20px 0}.loading{padding:40px}.progress-line{height:4px;border-radius:4px;background:#e3edf4;margin-top:14px;overflow:hidden}.progress-line i{display:block;background:var(--cyan);height:100%}.home-columns{display:grid;grid-template-columns:1fr 1fr;gap:24px}.home-columns .section-head{margin-top:8px}@media(max-width:650px){#shell{padding:0 18px 100px}.topbar{height:76px}.brand{font-size:21px}.brand img{width:40px;height:40px}.offline{font-size:9px;padding:4px 7px}.hero{min-height:234px;padding:24px 20px;border-radius:23px}.hero h1{font-size:29px;letter-spacing:0;line-height:1.45;max-width:190px}.hero-copy{width:65%}.hero p{font-size:11px;max-width:180px}.hero-tag{font-size:10px;margin-top:17px}.hero .eyebrow{font-size:9px;letter-spacing:1.4px}.mascot-card{width:123px;height:152px;right:13px;top:45px;transform:rotate(4deg)}.continue{padding:17px 16px;gap:7px;border-radius:20px}.continue h3{font-size:17px}.continue small{font-size:10px}.primary{font-size:12px;padding:9px 12px;border-radius:11px}.quick-grid{gap:8px;margin:16px 0 22px}.quick{font-size:11px;padding:14px 3px;border-radius:16px}.quick .icon{width:25px;height:25px;margin-bottom:8px}.card{padding:17px}.section-head{margin:24px 0 12px}.section-head h2{font-size:19px}.chapter-grid{grid-template-columns:1fr}.chapter{padding:17px}.book{gap:12px;padding:14px;align-items:flex-start;flex-direction:column}.cover{width:76px;height:104px}.book h3{font-size:13px}.book small{font-size:10px}.home-columns{display:block}.home-columns .section-head{margin-top:24px}.bottom{border-radius:19px 19px 0 0}.week{gap:3px}.day b{width:30px;height:30px}.count{font-size:11px}.count strong{font-size:19px}.check-head h3{font-size:16px}.badge{font-size:10px}.mine-head h2{font-size:21px}}@media(max-width:350px){#shell{padding-left:13px;padding-right:13px}.hero h1{font-size:26px}.hero{padding:22px 17px}.mascot-card{width:100px;height:140px;right:10px;top:49px}.hero p{max-width:158px}.continue h3{font-size:15px}.continue small{font-size:9px}.quick{font-size:10px}.day b{width:27px;height:27px}}@media(max-height:450px) and (min-width:651px){.topbar{height:66px}.hero{min-height:210px}.readerbar{height:46px}}@media(prefers-reduced-motion:reduce){*{scroll-behavior:auto!important;transition:none!important}}

/* Trusted same-origin course lifecycle gives the observer the entire app area. */
#classroom.model-observing>.readerbar{display:none}
#classroom.model-observing iframe{height:100%;flex:1}

/* Public single-lesson experience: all other features are absent, not hidden. */
[hidden]{display:none!important}.bottom{display:none}#main{padding-bottom:32px}.hero-tag{white-space:normal}.public-note{color:var(--muted);line-height:1.8}.public-links{display:flex;gap:12px;flex-wrap:wrap}.public-links a{display:inline-block;text-decoration:none;padding:14px 22px;border-radius:12px;background:#073e64;color:white;font-weight:700}.readerbar a{color:inherit;text-decoration:none}.lesson-page{max-width:1400px;margin:auto;padding:24px}.lesson-page h1{font-size:clamp(22px,3vw,34px);line-height:1.4}.lesson-grid{display:grid;grid-template-columns:minmax(320px,45%) minmax(0,1fr);gap:24px;align-items:start}.studio{position:sticky;top:16px;background:white;border:1px solid #d8e4ef;border-radius:20px;padding:14px}.studio canvas{display:block;width:100%;height:380px;border-radius:12px}.controls{display:flex;gap:8px;flex-wrap:wrap;margin-top:12px}.controls button{padding:8px 12px}.controls label{display:flex;align-items:center;gap:6px}.reading section{background:white;border-radius:18px;padding:22px;margin-bottom:18px;border:1px solid #d8e4ef}.reading p,.reading li{line-height:1.9}.reading h2{font-size:20px}.option{display:block;padding:10px;margin:8px 0;border:1px solid #d8e4ef;border-radius:10px}.model-overlay{position:fixed;inset:12px;z-index:1000;overflow:auto;top:12px}.model-overlay canvas{height:calc(100dvh - 200px)}.model-observing{overflow:hidden}.model-note{font-size:12px;line-height:1.6;color:#587086}.lesson-title-note{color:#587086;margin-bottom:22px}.feedback{min-height:24px;line-height:1.8}button:focus-visible,a:focus-visible,canvas:focus-visible{outline:3px solid #d45d46;outline-offset:3px}@media(max-width:700px){.lesson-page{padding:14px}.lesson-grid{display:block}.studio{top:0;z-index:2;padding:8px;margin-bottom:16px}.studio canvas{height:180px}.studio:not(.model-overlay) .model-note{font-size:11px;margin:4px 0}.controls{gap:6px;margin-top:6px}.controls button{min-height:36px;padding:4px 8px}.controls label{font-size:12px}.controls input[type=range]{width:90px}.reading section{padding:17px}.model-overlay{inset:6px}.model-overlay canvas{height:calc(100dvh - 200px)}}@media(max-height:450px){.lesson-grid{display:grid;grid-template-columns:42% minmax(0,1fr);gap:12px}.studio canvas{height:140px}.lesson-page h1{font-size:20px}.studio:not(.model-overlay) .model-note{display:none}.model-overlay canvas{height:calc(100dvh - 150px)}}@media(prefers-reduced-motion:reduce){*{transition:none!important;scroll-behavior:auto!important}}
