:root{--ink:#18372c;--muted:#63766c;--accent:#2f6c44;--paper:#fff;--bg:#f5f3ed;--line:#dce3da}*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--ink);font:17px/1.55 system-ui,sans-serif}a{color:var(--accent)}button,input,select,textarea{font:inherit}button{cursor:pointer;border:1px solid #b9cbbb;border-radius:11px;background:white;color:var(--ink);padding:10px 16px}button.primary,button[aria-pressed=true]{background:var(--accent);color:white;border-color:var(--accent)}button:disabled{opacity:.55;cursor:wait}button:focus-visible,a:focus-visible{outline:3px solid #dfac49;outline-offset:3px}input,select,textarea{width:100%;padding:11px;border:1px solid #b8c9bc;border-radius:9px;background:white;color:var(--ink)}textarea{min-height:115px;resize:vertical}label{display:block;font-weight:600;margin:16px 0 6px}label small{font-weight:400;color:var(--muted)}.wrap{max-width:1160px;margin:0 auto;padding:26px 20px 80px}.nav{background:white;border-bottom:1px solid var(--line);padding:12px 20px;display:flex;gap:18px;flex-wrap:wrap}.nav a{text-decoration:none;font-weight:650}.top,.actions,.tabs{display:flex;align-items:center;gap:10px;flex-wrap:wrap}.top{justify-content:space-between;margin-bottom:22px}.top h1{margin:0;font-size:32px}.tabs{margin:22px 0}.cards{display:grid;grid-template-columns:repeat(auto-fit,minmax(280px,1fr));gap:18px}.card,.panel{background:white;border:1px solid var(--line);border-radius:18px;padding:24px;margin:16px 0}.card h2,.panel h2{margin-top:0;font-size:24px}.muted{color:var(--muted)}.badge{display:inline-block;background:#e6eee2;padding:4px 10px;border-radius:7px;font-size:14px}.error{color:#962c28;white-space:pre-wrap}.notice{padding:12px 16px;border-radius:10px;background:#e6eee2;margin:12px 0}.danger{color:#962c28;border-color:#ce9b94}.grid{display:grid;grid-template-columns:1fr 1fr;gap:16px}.lesson{padding:16px 0;border-top:1px solid var(--line)}.lesson h3{margin:0 0 10px}.block{border:1px solid var(--line);border-radius:12px;margin:16px 0;padding:18px}.block textarea{min-height:140px}.blockhead{display:flex;justify-content:space-between;gap:10px;align-items:center}.blockhead select{width:auto}.cover{width:100%;height:180px;object-fit:cover;border-radius:12px}.content p{white-space:pre-wrap}.content img,.content video{max-width:100%;width:100%;border-radius:12px}.content audio{width:100%}.content iframe{border:0;width:100%;aspect-ratio:16/9;border-radius:12px}.content h2{margin-top:28px}.content{max-width:820px}.sticky{position:sticky;bottom:0;background:#fffc;padding:14px;border:1px solid var(--line);border-radius:12px;backdrop-filter:blur(8px)}dialog{border:1px solid var(--line);border-radius:18px;padding:28px;width:min(800px,94vw);max-height:90vh;overflow:auto;color:var(--ink)}dialog::backdrop{background:#10281e88}.progress{height:9px;background:#e2e8df;border-radius:10px;overflow:hidden;margin:14px 0}.progress span{display:block;height:100%;background:var(--accent)}.empty{padding:30px;text-align:center;color:var(--muted)}.check{display:flex;gap:10px;align-items:center}.check input{width:auto}.login{max-width:480px;margin:50px auto}.history{white-space:pre-wrap}.fileline{overflow-wrap:anywhere}.split{display:grid;grid-template-columns:280px 1fr;gap:24px}.side button{width:100%;text-align:left;margin-bottom:8px}.small{font-size:14px}#message:empty{display:none}@media(max-width:650px){.wrap{padding:18px 12px 60px}.grid,.split{grid-template-columns:1fr}.card,.panel{padding:18px}.top h1{font-size:27px}.actions button{flex-grow:1}dialog{padding:18px}.blockhead{flex-wrap:wrap}}
@media(max-width:650px){.sticky{position:static;background:var(--paper);backdrop-filter:none;margin-top:20px}}
.cover{height:auto;aspect-ratio:3/2;object-fit:contain;background:#f5efe5}
.content figure{margin:20px 0}