:root{color-scheme:light;--ink:#172033;--muted:#5e7186;--blue:#0b63ce;--deep:#12324a;--green:#168047;--orange:#f97316;--red:#dc2626;--line:#d7e5f0;--paper:#fffaf0;--radius:8px;font-family:"Microsoft YaHei","PingFang SC","Noto Sans CJK SC",Arial,sans-serif}
*{box-sizing:border-box}body{margin:0;background:linear-gradient(180deg,#eef9ff 0,#fff7db 48%,#f5fff1 100%);color:var(--ink);letter-spacing:0}.app{width:min(1180px,100%);margin:auto;padding:14px 14px 76px}.hero{border:1px solid #cfe3f7;border-radius:var(--radius);background:linear-gradient(135deg,#fff 0,#e7f7ff 42%,#fff0bd 100%);box-shadow:0 16px 42px rgba(20,44,70,.13);padding:clamp(18px,4vw,34px);display:grid;grid-template-columns:1fr minmax(300px,.76fr);gap:16px}.eyebrow{display:inline-flex;background:#fff2bd;border:1px solid #f5c542;border-radius:999px;padding:7px 10px;color:#854d0e;font-weight:900;font-size:13px}h1{font-size:clamp(31px,6vw,58px);line-height:1.04;margin:14px 0 10px;color:#0f3b57}.lead{font-size:clamp(16px,2.2vw,20px);line-height:1.7;color:#344256;margin:0}.stats{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:10px;margin-top:16px}.stat{background:rgba(255,255,255,.92);border:1px solid #d7e6f4;border-radius:var(--radius);padding:12px}.stat b{display:block;font-size:28px;color:var(--blue)}.stat span{font-weight:800;color:var(--muted);font-size:13px}.posterHero{position:relative;min-height:260px;border:2px solid #bde4ff;border-radius:var(--radius);background:linear-gradient(180deg,#dff6ff,#fff8d6 60%,#def7df);overflow:hidden}.posterHero:before{content:"";position:absolute;left:24px;right:24px;top:28px;height:112px;background:#fff;border:3px solid #0f3b57;border-radius:var(--radius);box-shadow:8px 8px 0 rgba(15,59,87,.12)}.posterHero b{position:absolute;left:44px;right:38px;top:50px;font-size:22px;line-height:1.25;color:#0f3b57}.avatar{position:absolute;bottom:22px;width:76px;height:120px}.avatar.left{left:38px}.avatar.right{right:38px}.avatar:before{content:"";position:absolute;left:18px;top:0;width:40px;height:40px;border-radius:50%;background:#ffd8ad;border:3px solid #111}.avatar:after{content:"";position:absolute;left:6px;top:48px;width:64px;height:70px;border-radius:24px 24px 8px 8px;background:#2563eb;border:3px solid #111}.avatar.right:after{background:#f97316}.speech{position:absolute;left:26%;right:13%;bottom:42px;background:#fff;border:3px solid #111;border-radius:var(--radius);padding:10px;font-weight:900;line-height:1.45}.controls{margin-top:12px;background:rgba(255,255,255,.94);border:1px solid var(--line);border-radius:var(--radius);padding:12px;display:grid;grid-template-columns:1fr 160px;gap:10px;position:sticky;top:0;z-index:8;backdrop-filter:blur(12px)}input,select{min-height:44px;border:1px solid #c6d7e7;border-radius:var(--radius);padding:0 12px;background:#fff;color:var(--ink);font:inherit}.tabs{display:grid;grid-template-columns:repeat(5,minmax(0,1fr));gap:8px;margin:12px 0}.tab,button{border:0;border-radius:var(--radius);font:inherit;font-weight:900;cursor:pointer}.tab{min-height:48px;background:#fff;border:1px solid #bdd7f0;color:#0f3b57}.tab.active{background:#0f3b57;color:#fff}.view{display:none}.view.active{display:block}.sectionTitle{display:flex;justify-content:space-between;gap:12px;align-items:end;margin:22px 0 12px}.sectionTitle h2{margin:0;font-size:clamp(25px,4vw,38px);color:#102a43}.sectionTitle p{margin:0;color:var(--muted);font-weight:800}.layout{display:grid;grid-template-columns:minmax(0,1fr) minmax(330px,.78fr);gap:12px;align-items:start}.main,.side,.card{background:#fff;border:1px solid #d7e5f0;border-radius:var(--radius);box-shadow:0 10px 30px rgba(15,23,42,.08)}.main{padding:14px}.side{position:sticky;top:82px;overflow:hidden}.meta{display:flex;gap:8px;flex-wrap:wrap;margin-bottom:10px}.pill{display:inline-flex;align-items:center;min-height:28px;border-radius:999px;background:#eef6ff;border:1px solid #cce4f6;color:#0f4f6d;padding:0 9px;font-weight:900;font-size:12px}.lessonTitle{font-size:clamp(23px,4vw,34px);line-height:1.18;margin:0 0 8px;color:#0f172a}.lessonSubtitle{font-weight:800;color:#536173;margin:0 0 12px;line-height:1.5}.panel{border:1px solid #dbe7f2;border-radius:var(--radius);padding:12px;background:#fbfdff}.panel h3{margin:0 0 8px;color:#0f3b57}.panel p{white-space:pre-wrap;margin:0;line-height:1.72}.posterHead{padding:14px;background:linear-gradient(90deg,#dff6ff,#fff);border-bottom:1px solid #d7e5f0;display:flex;justify-content:space-between;gap:10px}.sceneArt{position:relative;min-height:276px;background:linear-gradient(180deg,#fff 0 54%,#e6f7de 54%);overflow:hidden}.sceneBoard{position:absolute;left:18px;right:18px;top:20px;min-height:104px;border:2px solid #8bd3f7;border-radius:var(--radius);background:#f8fdff;padding:12px;font-size:18px;font-weight:900;line-height:1.45}.assetBox{position:absolute;left:50%;bottom:34px;transform:translateX(-50%);width:56%;min-height:92px;background:#fff;border:3px solid #111;border-radius:var(--radius);padding:10px;text-align:center;font-weight:800}.sceneGrid,.qSceneGrid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:8px;padding:12px;background:#f8fafc}.sceneTile,.qSceneTile{background:#fff;border:1px solid #dbe7f2;border-radius:var(--radius);padding:9px;line-height:1.45}.sceneTile b,.qSceneTile b{display:block;color:var(--blue);margin-bottom:4px}.assetImg{width:100%;display:block;border-top:1px solid #d7e5f0;background:#fff;max-height:360px;object-fit:contain;cursor:zoom-in}.toolbar{display:flex;gap:8px;flex-wrap:wrap;margin-top:12px}.primary,.ghost,.small{min-height:40px;padding:0 12px}.primary{background:#0f3b57;color:#fff}.ghost,.small{background:#fff;color:#0f3b57;border:1px solid #bdd7f0}.small{min-height:32px;font-size:13px}.grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:12px}.card{padding:14px}.termCard{border-left:7px solid #16a34a}.termCard strong{font-size:19px;color:#0f3b57}.termCard p{margin:8px 0;color:#344256;line-height:1.65}.videoCard{min-height:180px}.questionList{display:grid;gap:10px}.qCard{border-left:7px solid #0ea5e9}.practiceCard{border-left:7px solid #f97316}.bookCard{border-left:7px solid #16a34a}.qCard h3{font-size:17px;line-height:1.45}.qScene{background:linear-gradient(135deg,#e8f7ff,#fff7d6);border:1px solid #bfe0f4;border-radius:var(--radius);padding:10px;margin:8px 0;display:grid;gap:7px}.qScene b{color:#0f3b57}.options{display:grid;gap:8px}.opt{width:100%;text-align:left;background:#fff;border:2px solid #d6e4f0;border-radius:var(--radius);padding:10px;line-height:1.45}.opt.correct{border-color:#16a34a;background:#ecfdf3}.opt.wrong{border-color:#e11d48;background:#fff1f2}.answerBox{display:none;margin-top:10px;border:1px solid #dbe7f2;background:#f8fcff;border-radius:var(--radius);padding:10px;line-height:1.65}.answerBox.show{display:block}.shot{display:none;margin-top:10px}.shot.show{display:block}.shot img{width:100%;border:1px solid #dbe7f2;border-radius:var(--radius);background:#fff;cursor:zoom-in}.empty{background:#fff;border:1px dashed #bfd2e2;border-radius:var(--radius);padding:24px;text-align:center;color:#64748b;font-weight:900}.footer{font-size:12px;color:#64748b;margin-top:18px;line-height:1.6}.chapterGrid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:12px}.chapterCard{display:block;text-decoration:none;color:var(--ink);border-left:7px solid #0ea5e9}.chapterCard h3{margin:8px 0;font-size:21px;color:#102a43}.studyPath{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:8px;margin:10px 0 12px}.pathStep{border:1px solid #cfe0ee;background:#f8fcff;border-radius:var(--radius);padding:10px;line-height:1.45}.pathStep b{display:block;color:#0f3b57;margin-bottom:4px}.deepGrid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:10px;margin:12px 0}.conceptCard,.formulaCard{border:1px solid #d7e5f0;border-radius:var(--radius);padding:12px;background:#fff}.conceptCard{border-left:7px solid #0ea5e9}.formulaCard{border-left:7px solid #f97316;background:#fffaf3}.conceptCard h4,.formulaCard h4{margin:0 0 8px;font-size:17px;color:#102a43}.formula{display:block;background:#102a43;color:#fff;border-radius:var(--radius);padding:9px 10px;font-weight:900;margin:8px 0}.paragraphs{display:grid;gap:8px}.paragraphs p{border-left:4px solid #d7e5f0;background:#fff;border-radius:0 var(--radius) var(--radius) 0;padding:8px 10px;line-height:1.65}.paragraphs b{color:#0f3b57}.readPanel{background:#fffdf7}.qExplain{border:1px solid #dbe7f2;background:#fffdf5;border-radius:var(--radius);padding:10px;margin-top:10px;line-height:1.65}.imageHint{display:block;text-align:center;color:#0f4f6d;font-weight:900;padding:9px;background:#f8fcff;border-top:1px solid #d7e5f0}.lightbox{position:fixed;inset:0;background:rgba(5,14,25,.84);z-index:40;display:none;place-items:center;padding:14px}.lightbox.show{display:grid}.lightboxInner{width:min(1100px,96vw);max-height:94vh;background:#fff;border-radius:var(--radius);padding:10px;box-shadow:0 30px 80px rgba(0,0,0,.35)}.lightboxTop{display:flex;justify-content:space-between;gap:10px;align-items:center;margin-bottom:8px}.lightboxTitle{font-weight:900;color:#102a43}.lightbox img{width:100%;max-height:82vh;object-fit:contain;background:#fff;border:1px solid #d7e5f0;border-radius:var(--radius)}.segmentStack{display:grid;gap:14px}.segmentCard{border:1px solid #cfe0ee;border-radius:var(--radius);background:#fff;overflow:hidden}.segmentHead{display:flex;justify-content:space-between;gap:10px;align-items:center;padding:10px 12px;background:linear-gradient(90deg,#e7f7ff,#fff7d6);border-bottom:1px solid #d7e5f0}.segmentHead b{color:#0f3b57}.segmentBody{display:grid;gap:10px;padding:12px}.miniGrid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:10px}.miniPanel{border:1px solid #dbe7f2;background:#fbfdff;border-radius:var(--radius);padding:10px}.miniPanel h4{margin:0 0 8px;color:#0f3b57}.miniPanel p{margin:0;line-height:1.68;white-space:pre-wrap}.sentenceList{display:grid;gap:7px}.sentenceRow{border-left:4px solid #f59e0b;background:#fffaf0;border-radius:0 var(--radius) var(--radius) 0;padding:8px 10px;line-height:1.55}.segmentTakeaway{border:1px solid #c8ead5;background:#f0fdf4;border-radius:var(--radius);padding:10px;line-height:1.6}.fullRead{margin-top:12px;border:1px solid #d7e5f0;border-radius:var(--radius);background:#fff}.fullRead summary{padding:12px;font-weight:900;color:#0f3b57;cursor:pointer}.fullReadInner{display:grid;gap:10px;padding:0 12px 12px}
@media(max-width:980px){.hero,.layout{grid-template-columns:1fr}.side{position:static}.stats{grid-template-columns:repeat(2,minmax(0,1fr))}.chapterGrid{grid-template-columns:repeat(2,minmax(0,1fr))}}
@media(max-width:700px){.app{padding:10px 10px 70px}h1{font-size:36px}.hero{padding:14px}.sectionTitle{display:block}.sectionTitle h2{font-size:30px;line-height:1.15}.sectionTitle p{margin-top:6px}.stats,.controls,.grid,.sceneGrid,.qSceneGrid,.chapterGrid,.studyPath,.deepGrid,.miniGrid{grid-template-columns:1fr}.controls{position:static}.tabs{grid-template-columns:repeat(2,minmax(0,1fr))}.posterHero{display:none}.speech{left:18%;right:8%;font-size:14px}.avatar{transform:scale(.78);transform-origin:bottom}.avatar.right{transform:scale(.72)}body[data-page="chapter"] .hero{gap:8px}body[data-page="chapter"] h1{font-size:31px;line-height:1.08;margin:10px 0 6px}body[data-page="chapter"] .lead{font-size:15px;line-height:1.45}body[data-page="chapter"] .stats{grid-template-columns:repeat(3,minmax(0,1fr));gap:6px}body[data-page="chapter"] .stat{padding:8px}body[data-page="chapter"] .stat b{font-size:22px}body[data-page="chapter"] .stat span{font-size:11px}.lightbox{padding:6px}.lightboxInner{width:100%;max-height:96vh}.lightbox img{max-height:84vh}}
.explainSteps{margin:8px 0 0;padding:0;counter-reset:step;display:grid;gap:8px}.explainSteps li{list-style:none;position:relative;border:1px solid #dbe7f2;background:#fff;border-radius:var(--radius);padding:9px 10px 9px 42px;line-height:1.62}.explainSteps li:before{counter-increment:step;content:counter(step);position:absolute;left:10px;top:10px;width:23px;height:23px;border-radius:50%;background:#0b63ce;color:#fff;font-weight:900;display:grid;place-items:center;font-size:13px}.teachBox{border:2px solid #f5c542;background:#fffdf0;border-radius:var(--radius);padding:11px}.teachBox h4{margin:0 0 8px;color:#854d0e}.termLine{display:grid;gap:7px}.termLine div{border-left:5px solid #0ea5e9;background:#f8fcff;border-radius:0 var(--radius) var(--radius) 0;padding:8px 10px;line-height:1.6}.termLine b{color:#102a43}
/* Exam Picker */
.examPicker{display:grid;grid-template-columns:repeat(auto-fill,minmax(260px,1fr));gap:12px;padding:8px 0}
.examBtn{cursor:pointer;text-align:left;border:none;background:var(--card);border-radius:12px;padding:16px;transition:transform .15s,box-shadow .15s}
.examBtn:hover{transform:translateY(-2px);box-shadow:0 4px 12px rgba(0,0,0,.12)}
.examBtn h3{margin:0 0 8px;font-size:1rem;color:var(--text)}
.examBtn .pill{font-size:.8rem}