*{box-sizing:border-box}
body{margin:0;font-family:-apple-system,BlinkMacSystemFont,"PingFang SC","Microsoft YaHei","Noto Sans CJK SC",sans-serif;background:#f5f6f8;color:#1f2329;line-height:1.6}
a{color:#d4380d;text-decoration:none}a:hover{text-decoration:underline}
.wrap{max-width:1180px;margin:0 auto;padding:0 16px}
.topbar{background:#fff;border-bottom:1px solid #e8e8e8;position:sticky;top:0;z-index:10}
.topbar .wrap{display:flex;align-items:center;justify-content:space-between;height:56px}
.brand{font-weight:700;font-size:18px;color:#1f2329}
nav{display:flex;gap:16px;align-items:center}nav a{color:#1f2329}
.inline{display:inline}button.link{background:none;border:0;color:#1f2329;cursor:pointer;font:inherit;padding:0}
.announce{background:#fff7e6;color:#ad4e00;font-size:14px;padding:6px 0}
main{padding:20px 16px 40px}
.card{background:#fff;border-radius:10px;padding:20px 24px;margin-bottom:16px;box-shadow:0 1px 2px rgba(0,0,0,.04)}
.card.narrow{max-width:460px;margin:24px auto}.center{text-align:center}
.hero h1{margin:8px 0 4px}
.muted{color:#86909c}.small{font-size:13px}.mono{font-family:ui-monospace,Menlo,monospace;font-size:13px}
.ok{color:#389e0d}.err{color:#cf1322;background:#fff1f0;padding:8px 12px;border-radius:6px}
.btn{display:inline-block;background:#d4380d;color:#fff;border:0;border-radius:6px;padding:9px 20px;font-size:15px;cursor:pointer;text-decoration:none}
.btn:hover{background:#ad2102;text-decoration:none}.btn[disabled]{background:#bfbfbf;cursor:not-allowed}
.btn-sm{padding:4px 12px;font-size:13px}.btn.block{display:block;width:100%;margin-top:8px}
.btn-ghost{background:#fff;color:#d4380d;border:1px solid #d4380d}.btn-ghost:hover{background:#fff2e8}
.btn-danger{background:#cf1322}
label{display:block;margin:10px 0;font-size:14px;color:#4e5969}
input,select,textarea{width:100%;padding:8px 10px;border:1px solid #d9d9d9;border-radius:6px;font:inherit;margin-top:4px;background:#fff}
input[type=checkbox]{width:auto}
.course-head{display:flex;gap:20px;align-items:flex-start;flex-wrap:wrap}
.cover{width:280px;max-width:100%;aspect-ratio:16/9;object-fit:cover;border-radius:8px;background:#fafafa}
.cover.placeholder{display:flex;align-items:center;justify-content:center;color:#bbb;border:1px dashed #ddd}
.price{color:#d4380d;font-size:22px;font-weight:700}
.prose{white-space:pre-line}
.lesson-list{padding-left:0;list-style:none;margin:0}
.lesson-list li{padding:8px 0;border-bottom:1px dashed #eee;display:flex;gap:8px;align-items:center;flex-wrap:wrap}
.code{display:inline-block;min-width:36px;font-family:ui-monospace,Menlo,monospace;color:#86909c;font-size:13px}
.tag{font-size:12px;background:#e6f4ff;color:#0958d9;border-radius:4px;padding:0 6px}
.badge{display:inline-block;font-size:12px;border-radius:10px;padding:1px 8px;white-space:nowrap}
.st-unwatched{background:#f2f3f5;color:#86909c}.st-partial{background:#fff7e6;color:#d46b08}.st-completed{background:#f6ffed;color:#389e0d}
.os-pending{background:#fff7e6;color:#d46b08}.os-paid{background:#f6ffed;color:#389e0d}.os-closed,.os-refunded{background:#f2f3f5;color:#86909c}
.kv{width:100%;border-collapse:collapse;margin:12px 0}.kv th{text-align:left;color:#86909c;font-weight:400;width:90px;padding:6px 0}.kv td{padding:6px 0}
.table-wrap{overflow-x:auto}
.list{width:100%;border-collapse:collapse;font-size:14px}.list th,.list td{padding:8px;border-bottom:1px solid #f0f0f0;text-align:left;vertical-align:top}.list th{background:#fafafa;white-space:nowrap}
.pay-box{text-align:center;padding:12px 0}.qrcode{width:220px;height:220px}
.progress{height:8px;background:#f2f3f5;border-radius:4px;overflow:hidden;margin:8px 0}.progress .bar{height:100%;background:#52c41a}
.my-course{border-top:1px solid #f0f0f0;padding:16px 0}
.footer{padding:24px 0;color:#4e5969;font-size:14px;text-align:center}
/* 播放页 */
.player-layout{display:grid;grid-template-columns:1fr 340px;gap:16px}
@media (max-width:900px){.player-layout{grid-template-columns:1fr}}
.video-box{position:relative;background:#000;border-radius:10px;overflow:hidden;aspect-ratio:16/9}
.video-box video{width:100%;height:100%;display:block;background:#000}
.watermark{position:absolute;right:12px;top:10px;color:rgba(255,255,255,.35);font-size:13px;pointer-events:none;user-select:none}
.player-msg{position:absolute;left:0;right:0;bottom:50%;text-align:center;color:#fff;font-size:15px;pointer-events:none}
.lesson-bar{background:#fff;border-radius:10px;padding:12px 16px;margin-top:12px}
.lesson-bar h1{font-size:18px;margin:0 0 8px}
.lesson-actions{display:flex;gap:10px;align-items:center;flex-wrap:wrap}.lesson-actions label{margin:0;display:flex;gap:4px;align-items:center}.lesson-actions select{width:auto;margin:0;padding:3px 6px}
.lesson-nav{display:flex;justify-content:space-between;margin-top:10px}
.player-side{background:#fff;border-radius:10px;max-height:calc(100vh - 100px);overflow:auto;position:sticky;top:72px}
.side-head{padding:12px 14px;border-bottom:1px solid #f0f0f0;position:sticky;top:0;background:#fff}
.side-list{list-style:none;margin:0;padding:0}
.side-list li{display:flex;justify-content:space-between;gap:8px;align-items:center;padding:9px 14px;border-bottom:1px solid #f7f7f7;font-size:14px}
.side-list li a,.side-list li .locked{color:#1f2329;flex:1}.side-list li .locked{color:#a0a0a0}
.side-list li.active{background:#fff2e8}.side-list li.active a{color:#d4380d;font-weight:600}
/* 后台 */
.admin-nav{display:flex;gap:14px;flex-wrap:wrap;margin-bottom:16px}.admin-nav a{background:#fff;padding:6px 12px;border-radius:6px;color:#1f2329}
.stats{display:grid;grid-template-columns:repeat(auto-fit,minmax(160px,1fr));gap:12px}.stat{background:#fafafa;border-radius:8px;padding:12px}.stat b{font-size:24px;display:block}
.form-row{display:grid;grid-template-columns:repeat(auto-fit,minmax(160px,1fr));gap:12px}
.lesson-edit td input{margin:0;padding:4px 6px}.lesson-edit td{padding:4px}
.flash{background:#f6ffed;color:#389e0d;padding:8px 12px;border-radius:6px;margin-bottom:12px}
.lang-switch{display:flex;gap:6px;font-size:13px;margin-left:4px}.lang-switch a{color:#8a8f99;padding:2px 4px;border-radius:4px}.lang-switch a.on{color:#1f2329;font-weight:600;background:#f2f3f5}
@media (max-width:640px){.topbar .wrap{height:auto;flex-wrap:wrap;padding:8px 12px}nav{flex-wrap:wrap;gap:10px}}
.pay-options{display:flex;flex-direction:column;gap:8px;margin:12px 0}.pay-options label{display:flex;gap:8px;align-items:center;border:1px solid #e5e6eb;border-radius:8px;padding:10px 12px;cursor:pointer}.pay-options label.on,.pay-options label:has(input:checked){border-color:#1677ff;background:#f0f6ff}.pay-options .amt{margin-left:auto;font-weight:600}
.vietqr{display:flex;justify-content:center;margin:12px 0}.vietqr svg{max-width:100%;height:auto;border:1px solid #eee;border-radius:8px}
.mt-badge{display:inline-block;background:#fff4e5;color:#ad6800;border:1px solid #ffd591;border-radius:4px;padding:0 6px;font-size:12px}
.pay-options label input[type=radio]{width:auto;flex:0 0 auto;margin:0}.pay-options label>span:first-of-type{flex:1;text-align:left}.pay-options .amt{white-space:nowrap}
/* 观看码 */
.pass-qr{display:flex;gap:20px;flex-wrap:wrap;align-items:flex-start}.pass-qr>div:last-child{flex:1;min-width:260px}
.pass-active{background:#f6ffed;color:#389e0d}.pass-expired{background:#fff7e6;color:#d46b08}.pass-revoked{background:#fff1f0;color:#cf1322}
.pass-error .pass-msg{margin:8px 0}.pass-error hr{border:0;border-top:1px solid #eee;margin:16px 0}.nowrap{white-space:nowrap}