:root{--ink:#16211f;--muted:#6b7874;--line:#dce7e2;--paper:#f5f8f6;--card:#fff;--mint:#32b983;--blue:#3f74d8;--orange:#ee8b43}
*{box-sizing:border-box}body{margin:0;background:var(--paper);color:var(--ink);font:15px/1.6 Inter,"Microsoft YaHei",sans-serif}.topbar{height:72px;background:#fff;border-bottom:1px solid var(--line);display:flex;align-items:center;justify-content:space-between;padding:0 clamp(18px,5vw,76px);position:sticky;top:0;z-index:5}.brand{font-weight:800;font-size:20px;color:var(--ink);text-decoration:none;letter-spacing:.2px}.brand small{font-size:11px;color:var(--muted);font-weight:500;margin-left:8px}.brand-mark{color:var(--mint);font-family:monospace;margin-right:8px}.top-actions{display:flex;align-items:center;gap:16px;color:var(--muted);font-size:13px}.btn-ghost{border:1px solid var(--line);color:var(--ink);padding:7px 12px;border-radius:6px;text-decoration:none}.shell{max-width:1240px;margin:0 auto;padding:42px 22px 80px}.hero{display:flex;justify-content:space-between;gap:32px;align-items:end;padding:20px 0 46px}.eyebrow{font-size:11px;letter-spacing:2px;color:var(--mint);font-weight:800;margin:0 0 12px}.hero h1{font-size:clamp(34px,5vw,64px);line-height:1.06;margin:0;letter-spacing:-1px}.hero h1 em{font-style:normal;color:var(--blue)}.hero-copy{color:var(--muted);max-width:630px;margin:20px 0 0;font-size:16px}.hero-stat{background:var(--ink);color:#fff;padding:24px 26px;width:230px;border-radius:8px}.hero-stat strong{display:block;font-size:42px;line-height:1;color:#9debc8}.hero-stat span{display:block;color:#b8c9c3;font-size:12px;margin:8px 0 18px}.progress-line{height:5px;background:#3c4c48;border-radius:10px}.progress-line i{display:block;height:100%;width:0;background:var(--mint);border-radius:10px;transition:.4s}.tabs{display:flex;gap:26px;border-bottom:1px solid var(--line);margin-bottom:36px;overflow:auto}.tab{border:0;background:none;padding:13px 0;color:var(--muted);font-weight:700;white-space:nowrap;border-bottom:2px solid transparent}.tab.active{color:var(--ink);border-color:var(--mint)}.tab b{font-size:11px;background:#e7f4ee;color:#278f68;padding:2px 6px;border-radius:10px;margin-left:5px}.section-head{display:flex;justify-content:space-between;align-items:end;gap:20px;margin-bottom:22px}.section-head h2{font-size:28px;margin:0 0 4px}.muted{color:var(--muted);margin:0}.filter-pills{display:flex;gap:7px}.pill,.select{border:1px solid var(--line);background:#fff;color:var(--muted);padding:7px 13px;border-radius:5px}.pill.active{background:var(--ink);border-color:var(--ink);color:#fff}.grid{display:grid;grid-template-columns:repeat(3,1fr);gap:16px}.cardx{background:var(--card);border:1px solid var(--line);border-radius:8px;padding:22px;min-height:160px;display:flex;flex-direction:column}.cardx:hover{border-color:#acd9c5;box-shadow:0 8px 24px #193d2b0d}.cardx h3{font-size:18px;margin:7px 0}.cardx p{color:var(--muted);margin:0;font-size:13px}.tag{display:inline-block;color:var(--blue);font-size:11px;font-weight:800;letter-spacing:.5px}.card-foot{margin-top:auto;display:flex;justify-content:space-between;align-items:center;color:var(--muted);font-size:12px;padding-top:18px}.meter{height:4px;background:#edf2ef;margin-top:13px}.meter i{display:block;height:100%;background:var(--mint)}.quiz-layout{display:grid;grid-template-columns:285px 1fr;gap:18px}.quiz-list{display:flex;flex-direction:column;gap:6px;max-height:600px;overflow:auto}.q-item{border:1px solid var(--line);background:#fff;text-align:left;padding:11px 13px;border-radius:6px;color:var(--muted)}.q-item.active{border-color:var(--blue);color:var(--ink);box-shadow:0 3px 12px #294eaa12}.q-item small{display:block;color:var(--muted);font-size:10px}.quiz-card{background:#fff;border:1px solid var(--line);border-radius:8px;padding:30px;min-height:380px}.quiz-card h3{font-size:24px;margin:0 0 20px}.question-text{font-size:18px;white-space:pre-wrap}.option{display:block;border:1px solid var(--line);padding:12px 14px;border-radius:6px;margin:10px 0;cursor:pointer}.option:hover{border-color:var(--blue)}.option input{margin-right:10px}.submit-answer{background:var(--ink);color:#fff;border:0;border-radius:5px;padding:10px 18px;margin-top:17px}.feedback{margin-top:18px;padding:14px;border-radius:6px}.feedback.ok{background:#e5f7ee;color:#176c4c}.feedback.no{background:#fff0e7;color:#9a4e1d}.empty{color:var(--muted);padding:80px 20px;text-align:center}.toast{position:fixed;right:24px;bottom:24px;background:var(--ink);color:#fff;padding:12px 18px;border-radius:6px;display:none}.toast.show{display:block}@media(max-width:800px){.hero{display:block}.hero-stat{margin-top:28px;width:100%}.grid{grid-template-columns:1fr 1fr}.quiz-layout{grid-template-columns:1fr}.quiz-list{max-height:220px}.section-head{align-items:start;flex-direction:column}}@media(max-width:520px){.grid{grid-template-columns:1fr}.top-actions span{display:none}.shell{padding-top:25px}}
:root{--auth-dim:#16211f66}.auth-modal{position:fixed;inset:0;background:var(--auth-dim);display:grid;place-items:center;z-index:20}.auth-box{background:#fff;border-radius:8px;padding:30px;width:min(390px,calc(100% - 32px));position:relative;box-shadow:0 24px 80px #16211f33}.auth-box h2{margin:0 0 18px}.auth-box input{display:block;width:100%;border:1px solid var(--line);border-radius:5px;padding:11px 12px;margin:10px 0;font:inherit}.auth-close{position:absolute;right:14px;top:10px;border:0;background:none;font-size:26px;color:var(--muted)}.auth-actions{display:flex;gap:10px;align-items:center;margin-top:16px}.auth-hint{font-size:12px;margin-top:16px}
.filters{display:flex;gap:8px}.code-editor{width:100%;min-height:260px;background:#15231f;color:#e2fff2;border:0;border-radius:6px;padding:16px;font:13px/1.6 "JetBrains Mono",Consolas,monospace;resize:vertical}.code-actions{display:flex;align-items:center;gap:15px;margin-top:12px}.text-answer{width:100%;padding:12px;border:1px solid var(--line);border-radius:5px;font:inherit}.stats-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:12px;margin-bottom:18px}.stat-card{background:#fff;border:1px solid var(--line);border-radius:8px;padding:18px}.stat-card strong{display:block;font-size:28px;color:var(--blue)}.stat-card span{color:var(--muted);font-size:12px}.teacher-panel{background:#fff;border:1px solid var(--line);border-radius:8px;padding:22px}.inline-form{display:flex;gap:10px;margin:12px 0 18px}.inline-form input{flex:1;border:1px solid var(--line);border-radius:5px;padding:10px}.table-list{border-top:1px solid var(--line)}.table-row{display:flex;justify-content:space-between;padding:12px 0;border-bottom:1px solid var(--line)}.small-pad{padding:10px;text-align:center}@media(max-width:800px){.stats-grid{grid-template-columns:repeat(2,1fr)}.filters{width:100%}.filters select{flex:1}}@media(max-width:520px){.inline-form{display:block}.inline-form button{margin-top:10px}}
.lesson-box{background:#fff;border-radius:8px;padding:30px;width:min(760px,calc(100% - 32px));max-height:82vh;overflow:auto;position:relative;box-shadow:0 24px 80px #16211f33}.lesson-item{border-top:1px solid var(--line);padding:16px 0}.lesson-item p{color:var(--muted);margin:7px 0}.lesson-item pre,.import-result{background:#15231f;color:#e2fff2;padding:12px;border-radius:5px;white-space:pre-wrap;font-size:12px}.lesson-item small{color:var(--blue)}.import-result{min-height:25px}
.lesson-meta{font-size:12px;color:var(--muted);margin:8px 0}.lesson-meta code{color:var(--blue);word-break:break-word}