/* Shared classroom interface. Lesson colors are accents, not full-page fills. */
:root {
  --ui-bg:#f2f6fc; --ui-ink:#24344a; --ui-muted:#66768d;
  --ui-accent:#2563eb; --ui-soft:#eaf1ff; --ui-dark:#17324d;
  --ui-second:#5e91c6; --ui-line:#dae3ef; --ui-focus:#2563eb;
  --ui-shadow:0 8px 28px rgba(25,47,80,.045);
  --ui-font:'Pretendard','SUIT','Noto Sans KR','Malgun Gothic',system-ui,sans-serif;
}
body[data-lesson="2"] {
  --ui-bg:#f5f7fa; --ui-ink:#172b4d; --ui-muted:#617086;
  --ui-accent:#126f60; --ui-soft:#eaf4f1; --ui-dark:#172b4d;
  --ui-second:#cc715d; --ui-line:#dde4eb; --ui-focus:#168b78;
}
body[data-lesson="3"] {
  --ui-bg:#f4f1eb; --ui-ink:#30343b; --ui-muted:#746c68;
  --ui-accent:#7b4354; --ui-soft:#f2e9ed; --ui-dark:#30343b;
  --ui-second:#557b99; --ui-line:#e2dbd5; --ui-focus:#7b4354;
}
body[data-lesson="4"] {
  --ui-bg:#f5f3fa; --ui-ink:#302d45; --ui-muted:#747085;
  --ui-accent:#695594; --ui-soft:#eee9f7; --ui-dark:#211d3d;
  --ui-second:#387f6f; --ui-line:#e2ddeb; --ui-focus:#695594;
}
html{scroll-padding-top:90px}
body{background:var(--ui-bg);color:var(--ui-ink);font:15px/1.75 var(--ui-font);letter-spacing:-.015em;-webkit-font-smoothing:antialiased}
a,a:hover,a:visited{text-decoration:none;color:var(--ui-accent)}
a,button,input,select{transition:background-color .15s,border-color .15s,box-shadow .15s}
a:hover{color:var(--ui-dark)}
a:focus-visible,button:focus-visible,input:focus-visible,select:focus-visible,summary:focus-visible{outline:3px solid var(--ui-focus);outline-offset:3px}
button,input,select{font:inherit;letter-spacing:inherit;min-height:40px;border:1px solid var(--ui-line);border-radius:9px;background:#fff;color:var(--ui-ink);padding:8px 13px}
button:hover{background:var(--ui-soft);border-color:var(--ui-accent)}
button:disabled{opacity:.4;cursor:default}
input::placeholder{color:#8994a5}
input:focus,select:focus{border-color:var(--ui-accent)}
header{background:var(--ui-dark);padding:12px max(24px,calc((100% - 1432px)/2));gap:8px;align-items:center;min-height:58px;border-bottom:1px solid #ffffff12}
header a,header a:visited{font-size:12px;font-weight:600;color:#dde5f0;padding:6px 10px;border-radius:6px}
header a:hover{background:#ffffff12;color:#fff}
header span{font-size:11px;letter-spacing:.01em;color:#c1c8d3;margin-left:auto}
body[data-lesson]>.hero{max-width:1432px;margin:24px auto 0;padding:24px 28px;background:#fff;color:var(--ui-ink);border:1px solid var(--ui-line);border-left:4px solid var(--ui-accent);border-radius:14px;box-shadow:var(--ui-shadow)}
body[data-lesson]>.hero h1{font-size:25px;line-height:1.4;letter-spacing:-.045em;font-weight:750;margin:0 0 12px}
body[data-lesson]>.hero p{font-size:13px;line-height:1.7;margin:4px 0;color:var(--ui-muted)}
body[data-lesson]>.hero a{display:inline-flex;align-items:center;font-size:12px;font-weight:650;color:var(--ui-accent);padding:5px 10px;margin:12px 4px 0 0;border:1px solid var(--ui-line);border-radius:6px;background:#fff}
body[data-lesson]>.hero a:hover{background:var(--ui-soft);border-color:var(--ui-accent)}
.toolbar{position:sticky;top:8px;max-width:1432px;margin:16px auto 0;padding:12px 18px;border:1px solid var(--ui-line);border-radius:12px;box-shadow:0 5px 20px #20374f08;background:#fffffffa;gap:12px;z-index:3}
.toolbar label{font-size:12px;font-weight:600;color:var(--ui-muted);display:flex;align-items:center;gap:10px}
.toolbar select{font-size:13px;min-width:95px}
.toolbar input{font-size:13px;max-width:240px;width:210px}
.toolbar button{font-size:13px;font-weight:600}
#counter{font-size:13px;font-weight:700;color:var(--ui-accent);min-width:74px;text-align:center;font-variant-numeric:tabular-nums}
#next{background:var(--ui-dark);color:#fff;border-color:var(--ui-dark)}
#next:hover{background:var(--ui-accent);border-color:var(--ui-accent)}
#print{margin-left:auto;font-size:12px;color:var(--ui-muted);background:transparent}
.toc{max-width:1432px;padding:12px 18px;background:#fff;border:1px solid var(--ui-line);border-radius:10px;margin:12px auto}
summary{font-size:13px;font-weight:650;list-style-position:inside;color:var(--ui-ink)}
.toc[open]{max-height:300px;overflow:auto}
.toc a{padding:8px 12px;border-bottom:1px solid var(--ui-line);font-size:13px;color:var(--ui-muted)}
.toc a:hover{background:var(--ui-soft);color:var(--ui-accent);border-radius:5px}
.toc a[hidden]{display:none}
.split-controls{padding:0;max-width:1432px;margin:18px auto 14px;gap:7px}
.split-controls button{font-size:13px;font-weight:650;min-height:39px;padding:9px 16px;background:#fff;color:var(--ui-muted);border:1px solid var(--ui-line);border-radius:9px}
.split-controls button:hover{background:var(--ui-soft);color:var(--ui-accent);border-color:var(--ui-accent)}
.split-controls button[aria-expanded="true"]{color:var(--ui-accent);background:var(--ui-soft);border-color:var(--ui-accent);box-shadow:inset 0 -2px var(--ui-accent)}
.split-controls button[data-open-panel="prompt"]{border-color:var(--ui-second);color:var(--ui-second)}
.split-controls button[data-open-panel="prompt"][aria-expanded="true"]{background:var(--ui-dark);color:#fff;border-color:var(--ui-dark);box-shadow:none}
.split-hint{margin-left:auto;font-size:11px;color:var(--ui-muted)}
.course-workspace{max-width:1480px;margin:0 auto;padding:0 24px;gap:20px}
.split-open .course-workspace{grid-template-columns:minmax(0,calc(100% - var(--panel-width) - 20px)) minmax(0,var(--panel-width))}
.slide-main .slide-card{border:1px solid var(--ui-line);border-radius:14px;padding:18px 20px 16px;background:#fff;box-shadow:var(--ui-shadow)}
body[data-lesson="3"] .slide-card:has(.handoff),body[data-lesson="4"] .slide-card:has(.handoff){border-top:1px solid var(--ui-line)}
.meta{font-size:11px;letter-spacing:.025em;color:var(--ui-muted);font-weight:600}
.slide-main .slide-card>h2{font-size:19px!important;line-height:1.45;letter-spacing:-.025em;font-weight:750;color:var(--ui-ink);margin:8px 0 18px!important}
.actual-slide{border:1px solid var(--ui-line);background:var(--ui-bg);border-radius:9px;margin:12px 0 18px}
.actual-slide a{padding:0;background:none;border:0}
.image-caption{font-size:11px;padding:10px 14px;background:var(--ui-bg);color:var(--ui-muted);border-top:1px solid var(--ui-line)}
.slide-main .connection{font-size:12px;line-height:1.7;padding:12px 0 0;margin:12px 0;color:var(--ui-muted);border-top:1px solid var(--ui-line);border-left:0!important}
.slide-main .pdf{font-size:12px;font-weight:650;color:var(--ui-accent);border:1px solid var(--ui-line);border-radius:7px;background:#fff;padding:7px 12px;margin:0}
.slide-main .pdf:hover{background:var(--ui-soft);border-color:var(--ui-accent)}
.detail-panel{top:83px;border:1px solid var(--ui-line);border-radius:14px;box-shadow:var(--ui-shadow);max-height:calc(100vh - 103px);scrollbar-width:thin;scrollbar-color:var(--ui-line) transparent}
.detail-panel-head{background:var(--ui-soft);color:var(--ui-ink);border-bottom:1px solid var(--ui-line);padding:19px 22px;gap:12px}
.detail-panel-head small{font-size:11px;line-height:1.55;color:var(--ui-muted);max-width:320px}
.detail-panel-head h2{font-size:21px;font-weight:750;letter-spacing:-.035em;color:var(--ui-accent);margin:6px 0 0}
.detail-panel-head button{font-size:11px;color:var(--ui-muted);border:1px solid var(--ui-line);background:#fff;padding:5px 10px;min-height:32px;white-space:nowrap}
.panel-resize{padding:11px 22px;background:#fff;border-color:var(--ui-line);color:var(--ui-muted);font-size:11px}
.panel-resize input{accent-color:var(--ui-accent);min-height:auto;border:0}
#panel-content{padding:22px 24px 28px;font-size:15px;line-height:1.85;color:var(--ui-ink)}
#panel-content h3{font-size:14px;font-weight:750;letter-spacing:-.01em;margin:24px 0 10px;padding:0 0 9px;border-color:var(--ui-line);color:var(--ui-accent)}
#panel-content h3:first-child{margin-top:0}
#panel-content p{margin:12px 0;word-break:keep-all;overflow-wrap:anywhere}
#panel-content a{font-size:12px;font-weight:650}
#panel-content .files{gap:8px}
#panel-content .files a{display:flex;padding:12px 14px;border:1px solid var(--ui-line);border-left:3px solid var(--ui-second);border-radius:8px;background:var(--ui-bg);color:var(--ui-ink);font-size:12px;line-height:1.5}
#panel-content .files a:hover{background:var(--ui-soft);border-color:var(--ui-accent)}
.panel-note,.copy-status{font-size:12px;line-height:1.75;color:var(--ui-muted)}
.copy-prompt{font-size:12px;font-weight:650;background:var(--ui-accent);border-color:var(--ui-accent);color:#fff;padding:8px 14px;min-height:37px;margin-right:8px}
.copy-prompt:hover{background:var(--ui-dark);border-color:var(--ui-dark);color:#fff}
#panel-content .prompt-text{background:var(--ui-dark);color:#f1f2f6;border:0;border-radius:10px;padding:20px;font:13px/1.85 'Cascadia Code',Consolas,monospace;letter-spacing:0;margin:18px 0}
.handoff{max-width:1432px;background:var(--ui-soft);border:1px solid var(--ui-line);border-left:3px solid var(--ui-second);border-radius:10px;padding:20px 24px;color:var(--ui-ink)}
.handoff h2{font-size:18px;margin-top:0}.handoff p{font-size:13px}.handoff a{font-size:13px;font-weight:700}
footer{background:transparent;color:var(--ui-muted);border-top:1px solid var(--ui-line);padding:24px;margin-top:30px;font-size:11px;letter-spacing:.02em}
footer a{color:var(--ui-muted);font-weight:650}footer a:hover{color:var(--ui-accent)}
.hub{max-width:1432px;gap:18px;padding:0}.hub section{border:1px solid var(--ui-line);border-radius:14px;box-shadow:var(--ui-shadow);padding:28px}
.hub section>span{font-size:11px;font-weight:650;color:var(--ui-muted)}.hub h2{font-size:23px;letter-spacing:-.04em;margin:12px 0}.hub p{font-size:13px;color:var(--ui-muted)}
.hub section:nth-child(1){border-top:4px solid #2563eb}.hub section:nth-child(2){border-top:4px solid #168b78}.hub section:nth-child(3){border-top:4px solid #7b4354}.hub section:nth-child(4){border-top:4px solid #695594}
.hub a{display:inline-flex;padding:8px 12px;border:1px solid var(--ui-line);border-radius:7px;font-size:12px;margin:10px 2px 0 0;color:var(--ui-ink)}.hub a:hover{background:var(--ui-soft)}
.v-journey{background:var(--ui-dark);padding-top:35px;padding-bottom:36px}.v-journey h2{font-size:34px;line-height:1.4;font-weight:650}.v-journey .v-flow{margin-bottom:0}
@media(min-width:901px) and (max-width:1500px){body[data-lesson]>.hero,.toolbar,.toc,.split-controls,.handoff,.hub{margin-left:24px;margin-right:24px}.toolbar{max-width:none}.split-controls{max-width:none}.split-hint{display:none}}
@media(max-width:900px){header{padding:10px 16px;gap:2px}header a{font-size:11px;padding:5px 8px}header span{width:100%;margin:5px 8px 0;font-size:10px}body[data-lesson]>.hero{margin:16px;padding:20px}body[data-lesson]>.hero h1{font-size:22px}.toolbar{position:static;margin:12px 16px;padding:12px;gap:9px}.toolbar label{font-size:11px}.toolbar input{width:160px}.toolbar button{font-size:12px;padding:7px 10px}#print{margin-left:0}.toc{margin:12px 16px}.split-controls{margin:16px;padding:0;gap:7px}.split-controls button{font-size:12px;padding:8px 12px}.split-hint{display:none}.course-workspace,.split-open .course-workspace{grid-template-columns:1fr;padding:0 16px;gap:16px}.detail-panel{position:static;max-height:none}.slide-main .slide-card{padding:16px}.slide-main .slide-card>h2{font-size:17px!important}.panel-resize{display:none}#panel-content{padding:20px;font-size:15px}.detail-panel-head{padding:16px 20px}.handoff,.hub{margin:20px 16px}.hub{grid-template-columns:1fr}.v-journey{padding:28px 20px}.v-journey h2{font-size:27px}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}a,button,input,select{transition:none}}
@media print{body{font-size:12px;background:#fff!important;color:#000}.toolbar,.split-controls,.toc,.detail-panel,header,footer{display:none!important}body[data-lesson]>.hero{box-shadow:none;margin:0;padding:10px;border:0;background:#fff}.course-workspace,.split-open .course-workspace{display:block;padding:0}.slide-main .slide-card{box-shadow:none;border:0}.actual-slide{border:0}.handoff{background:#fff;border:1px solid #ccc}.prompt-text{white-space:pre-wrap}.hub{display:block}.hub section{box-shadow:none}}