@import url('https://fonts.googleapis.com/css2?family=Noto+Sans+SC:wght@400;500;600;700&display=swap');
:root{--ink:#183d36;--muted:#788780;--paper:#f5f5ef;--line:#e2e7df;--green:#216b55;--lime:#d9edb7}*{box-sizing:border-box}body{margin:0;background:var(--paper);color:var(--ink);font-family:'Noto Sans SC',system-ui,sans-serif;font-size:14px}button,input,select,textarea{font:inherit}button,a,input,textarea,select{outline-offset:4px}button{cursor:pointer;border:1px solid var(--line);background:white;color:var(--ink);border-radius:9px;padding:10px 15px;transition:background .15s}button:hover{background:#edf3e8}button:disabled{opacity:.55;cursor:wait}.primary{background:var(--green);color:white;border-color:var(--green)}.primary:hover{background:#174f40}a{color:var(--green);text-decoration:none}a:hover{text-decoration:underline}[hidden]{display:none!important}.eyebrow{font-size:10px;letter-spacing:1.6px;font-weight:700;color:var(--muted)}.sidebar{position:fixed;inset:0 auto 0 0;width:225px;background:#fbfcf7;border-right:1px solid var(--line);padding:32px 22px;display:flex;flex-direction:column;gap:25px}.brand{display:flex;align-items:center;gap:12px;font-size:24px;font-weight:700;color:var(--ink)}.brandmark{display:inline-flex;background:var(--ink);color:var(--lime);width:43px;height:43px;align-items:center;justify-content:center;border-radius:13px;font-size:24px}.brand small{display:block;font-size:10px;letter-spacing:2px;font-weight:400;margin-top:3px}.sidebar nav{display:grid;gap:8px}.nav{text-align:left;border:0;background:transparent;padding:14px 12px}.nav.active{background:#e7efdf;color:#264d35;font-weight:700}.goal{margin-top:auto;border-radius:14px;padding:18px;background:#edf1e5;line-height:1.8}.goal strong{display:block}.goal small,.goal span{font-size:11px;color:var(--muted)}.goal p{font-size:12px}.track{height:5px;border-radius:8px;background:#d9e0d1;margin:12px 0;overflow:hidden}.track i{display:block;background:var(--green);height:100%;width:0}.back{font-size:12px}main{margin-left:225px;max-width:1700px;padding:35px 38px}header{display:flex;justify-content:space-between;align-items:center;margin-bottom:24px}h1{font-size:28px;font-weight:600;letter-spacing:-1px;margin:9px 0}h2{font-size:16px;margin:0}h3{font-size:23px;margin:12px 0}.badge{font-size:10px;letter-spacing:1px;background:#e7ecdf;padding:10px 15px;border-radius:20px;white-space:nowrap}#status{min-height:35px;color:var(--muted);font-size:12px}.session-bar{display:flex;justify-content:space-between;align-items:center;gap:20px;margin-bottom:20px}.session-bar strong{display:block;font-size:15px}.session-bar small{display:block;margin-top:6px;color:var(--muted);font-size:11px}.page-controls{display:flex;align-items:center;gap:8px}.page-controls input{width:65px;padding:8px;border:1px solid var(--line);border-radius:6px;background:white}.class-grid{display:grid;grid-template-columns:minmax(260px,.9fr) minmax(330px,1.1fr);gap:22px;align-items:start}.panel{background:#fff;border:1px solid var(--line);border-radius:16px;overflow:hidden}.panel-head{padding:21px 24px;display:flex;justify-content:space-between;align-items:center;border-bottom:1px solid var(--line);gap:10px}.panel-head a,.tiny{font-size:10px;color:var(--muted)}.book-image{background:#e8e9df;padding:20px;min-height:350px}.book-image img{display:block;width:100%;box-shadow:0 5px 22px #213a3020}.book details{padding:18px;font-size:12px}.book summary{cursor:pointer;color:var(--muted)}pre{white-space:pre-wrap;line-height:1.7;max-height:380px;overflow:auto;font-family:Georgia,serif}.teacher-dot{display:inline-block;width:9px;height:9px;background:#6c9d62;border-radius:50%;margin-right:10px}.teacher-intro{padding:25px;background:linear-gradient(110deg,#f1f6e9,#fcfdf8)}.teacher-intro p{color:#718273;line-height:1.9;font-size:12px;max-width:400px}.teacher-intro button{margin-top:8px}.prose{padding:25px;white-space:pre-wrap;line-height:2.1;max-height:540px;overflow:auto;font-size:14px}.placeholder{color:var(--muted);font-size:13px}.source-label{font-size:10px;color:var(--muted);padding:0 25px;margin:0 0 15px}.audio{padding:18px 24px;background:#f6f8f1;border-top:1px solid var(--line);display:flex;flex-wrap:wrap;gap:8px;align-items:center}.audio button{padding:8px 10px;font-size:12px}.audio label{font-size:11px;color:var(--muted)}.audio select{padding:7px;max-width:170px;border:1px solid var(--line);border-radius:5px;background:white}.audio small{width:100%;font-size:10px;color:var(--muted);margin-top:4px}.lesson-actions{padding:18px 24px 10px;display:flex;gap:8px;flex-wrap:wrap}.lesson-actions button{font-size:12px}textarea{display:block;margin:0 24px 20px;width:calc(100% - 48px);min-height:70px;resize:vertical;border:1px solid var(--line);padding:12px;border-radius:8px;font-size:12px}.conversation{margin-top:24px}.quick{display:flex;flex-wrap:wrap;gap:8px;padding:18px 24px}.quick button{border-radius:20px;font-size:11px;background:#f5f7ef}#messages{padding:0 24px;max-height:450px;overflow:auto}.message{white-space:pre-wrap;line-height:1.9;margin:12px 0;padding:15px 18px;border-radius:12px;background:#f5f7f1}.message.user{background:#e7f0e6;margin-left:35px}.message b{display:block;font-size:10px;color:var(--muted);margin-bottom:8px}.message button{display:block;margin-top:10px;font-size:11px}#questionForm{display:flex;gap:8px;padding:12px 24px}#question{flex:1;min-width:0;padding:12px;border:1px solid var(--line);border-radius:8px}#micHint{display:block;margin:0 24px 20px;color:var(--muted);font-size:10px}.section-intro{max-width:680px;margin:15px 0 30px}.section-intro h2{font-size:26px}.section-intro p{line-height:2;color:var(--muted)}.topics{display:grid;grid-template-columns:repeat(3,1fr);gap:16px}.topic{padding:23px}.topic strong{font-size:32px;display:block;margin:10px 0}.topic small{color:var(--muted)}.coverage{padding:24px;margin-top:25px;line-height:2}.coverage h3{font-size:17px}.coverage p{color:var(--muted);font-size:12px}.stats{display:flex;gap:16px}.stats>div{flex:1;background:white;border:1px solid var(--line);border-radius:14px;padding:24px}.stats strong{display:block;font-size:30px}.stats span{font-size:12px;color:var(--muted)}.review-item{display:flex;justify-content:space-between;align-items:center;gap:10px;background:white;border:1px solid var(--line);padding:18px;margin-top:12px;border-radius:12px}.review-item small{display:block;color:var(--muted);margin-top:6px}.review-item button{font-size:11px;margin:3px}footer{font-size:10px;color:var(--muted);display:flex;justify-content:space-between;gap:15px;margin-top:38px;padding:15px 0}.login{min-height:100vh;display:grid;place-items:center;background:radial-gradient(ellipse at top left,#dfeacb,transparent 60%),#f5f5ef}.login-card{width:min(430px,90vw);padding:40px;background:#ffffffd9;border:1px solid white;border-radius:24px;display:grid;gap:17px;box-shadow:0 20px 80px #153e3410}.login-card h1{font-size:31px;line-height:1.5}.login-card p{color:var(--muted);font-size:12px;margin:0;line-height:1.8}.login-card label,.login-card small{font-size:11px;color:var(--muted)}.login-card input{padding:12px;border-radius:8px;border:1px solid var(--line);width:100%}#loginError{color:#a9412f}
@media(min-width:1500px){.book-image{max-height:860px;overflow:auto}}@media(max-width:1100px){.sidebar{width:185px;padding:25px 15px}main{margin-left:185px;padding:25px 22px}.class-grid{grid-template-columns:1fr}.book-image{max-height:480px;overflow:auto}.book-image img{max-width:600px;margin:auto}.topics{grid-template-columns:repeat(2,1fr)}}@media(max-width:800px){.sidebar{position:static;width:100%;padding:15px;border-right:0;border-bottom:1px solid var(--line);display:block}.brand{font-size:20px}.brandmark{height:34px;width:34px;font-size:20px}.sidebar>.eyebrow,.goal,.back{display:none}.sidebar nav{display:flex;margin-top:15px;gap:4px}.nav{flex:1;font-size:12px;text-align:center;padding:10px 4px}.brand small{display:inline;margin-left:10px}main{margin:0;padding:23px 14px}header h1{font-size:22px}.badge{display:none}.session-bar{align-items:start;flex-direction:column;gap:12px}.page-controls{width:100%;justify-content:space-between}.class-grid{gap:15px;grid-template-columns:minmax(0,1fr)}.panel-head{padding:18px}.book-image{max-height:390px;padding:12px}.teacher-intro,.prose{padding:20px}.quick{padding:15px}.conversation .tiny{display:none}.audio{padding:15px}.topics{grid-template-columns:1fr 1fr;gap:10px}.topic{padding:15px}.stats{gap:8px}.stats>div{padding:14px 9px}.stats strong{font-size:23px}.stats span{font-size:10px}#questionForm{padding:12px}#question{font-size:12px}#send{font-size:12px;padding:8px}footer{display:block;line-height:2}footer span{display:block}.review-item{align-items:start;flex-direction:column}}

.book-navigation{margin-bottom:22px}.book-navigation .panel-head button{font-size:11px;padding:8px 12px}.chapter-tools{display:flex;gap:10px;padding:16px 20px}.chapter-tools input{flex:1;min-width:0;border:1px solid var(--line);border-radius:8px;padding:10px}.chapter-list{max-height:420px;overflow:auto;padding:0 20px 16px;display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:9px}.chapter-row{border:1px solid var(--line);border-radius:10px;padding:10px;min-width:0}.chapter-row.current{background:#edf5e6;border-color:#72966e}.chapter-open{text-align:left;display:block;width:100%;border:0;background:transparent;padding:5px}.chapter-open strong{display:block;font-size:13px}.chapter-open small{display:block;font-size:10px;color:var(--muted);margin-top:5px}.chapter-row details{font-size:11px;padding:6px}.chapter-row summary{cursor:pointer;color:var(--green)}.chapter-section{display:block;text-align:left;width:100%;font-size:10px;padding:7px;border:0;border-bottom:1px solid var(--line)}.reading-location{padding:17px 20px;background:#f3f7ed;border-top:1px solid var(--line);display:grid;gap:9px}.reading-location span{font-size:11px;color:var(--muted)}.reading-location button,.reading-location label{font-size:11px;margin-right:7px}.reading-focus .class-grid{grid-template-columns:1fr}.reading-focus .teacher,.reading-focus .conversation{display:none}.reading-focus .book-image{max-height:none;overflow:visible}.reading-focus .book-image img{max-width:900px;margin:auto}.reading-focus .book{max-width:1000px;margin:auto;width:100%}@media(max-width:650px){.chapter-list{grid-template-columns:1fr}.chapter-tools{padding:12px}.chapter-tools button{font-size:11px;padding:8px}.book-navigation .panel-head{gap:7px}.book-navigation h2{font-size:14px}}

/* Readable bilingual chapter navigation, including narrow screens. */
.chapter-open small{font-size:16px;line-height:1.6;color:#415c53;margin-top:8px;overflow-wrap:anywhere}.chapter-open strong{font-size:16px;line-height:1.5}.chapter-section{font-size:15px;line-height:1.6;padding:10px 7px;overflow-wrap:anywhere}.chapter-row summary{font-size:14px;padding:5px 0}.book pre{font-size:18px;line-height:1.8}

.avatar-card{display:flex;align-items:center;gap:28px;padding:22px 28px;margin-bottom:18px;background:linear-gradient(115deg,#f0f5e7,#fffdf6)}.avatar-stage{width:195px;flex-shrink:0}.avatar-stage svg{display:block;width:100%;height:auto}.avatar-copy h2{font-size:22px;line-height:1.5}.avatar-copy p:not(.eyebrow){line-height:1.7;color:#52685b}.avatar-copy small{display:block;color:#748174;font-size:11px;line-height:1.8;margin-top:14px}.avatar-actions{display:flex;flex-wrap:wrap;gap:8px}.avatar-actions button{font-size:13px}.avatar-mouth{display:none;transform-origin:120px 130px}.avatar-stage.speaking .avatar-mouth{display:block;animation:teacher-mouth .3s ease-in-out infinite alternate}.avatar-stage.speaking .avatar-smile{display:none}.avatar-stage.speaking .avatar-head{transform-origin:120px 145px;animation:teacher-nod 2s ease-in-out infinite}.avatar-eyes{transform-origin:120px 99px;animation:teacher-blink 5.7s infinite}@keyframes teacher-mouth{from{transform:scaleY(.25)}to{transform:scaleY(1)}}@keyframes teacher-nod{0%,100%{transform:rotate(-1deg)}50%{transform:rotate(1deg)}}@keyframes teacher-blink{0%,43%,47%,100%{transform:scaleY(1)}45%{transform:scaleY(.08)}}@media(max-width:800px){.avatar-card{gap:14px;padding:16px}.avatar-stage{width:125px}.avatar-copy h2{font-size:18px}.avatar-copy .eyebrow{font-size:8px}.avatar-actions button{font-size:12px;padding:9px}.avatar-copy small{font-size:10px}}@media(max-width:430px){.avatar-card{flex-direction:column;text-align:center}.avatar-stage{width:140px}.avatar-actions{justify-content:center}}@media(prefers-reduced-motion:reduce){.avatar-stage *{animation:none!important}}

.library-panel{margin-bottom:24px}.library-body{padding:22px 24px}.library-body>p{line-height:1.8;color:#52685b;margin-top:0}.import-grid{display:grid;grid-template-columns:1fr 1fr;gap:20px}.import-grid form{display:flex;flex-direction:column;gap:10px;padding:18px;background:#f5f8f0;border-radius:12px}.import-grid label{font-weight:600}.import-grid input{width:100%;min-width:0;border:1px solid var(--line);padding:11px;border-radius:8px;background:#fff}.import-grid small,.library-privacy{color:#65776d;font-size:12px;line-height:1.7}.library-select{display:flex;gap:14px;align-items:center;margin:18px 0}.library-select select{flex:1;min-width:0;padding:12px;border:1px solid var(--line);border-radius:8px;background:#fff}.library-privacy{display:block}#importStatus{margin-top:16px;color:#216b55}#readingText{font-family:inherit;font-size:18px;line-height:1.9;max-height:none;overflow-wrap:anywhere;background:#fffdf6;padding:20px;margin:0}.book-image:has(#readingText:not([hidden])){max-height:720px;overflow:auto}.reading-focus .book-image:has(#readingText:not([hidden])){max-height:none}.chapter-row.current{background:#edf5e6}@media(max-width:650px){.import-grid{grid-template-columns:1fr}.library-body{padding:16px}.library-select{align-items:stretch;flex-direction:column;gap:8px}.library-panel .panel-head h2{font-size:18px}}