.replayer-wrapper{position:relative}.replayer-mouse{position:absolute;width:20px;height:20px;transition:left .05s linear,top .05s linear;background-size:contain;background-position:center center;background-repeat:no-repeat;background-image:url(data:image/svg+xml;base64,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);border-color:transparent}.replayer-mouse:after{content:"";display:inline-block;width:20px;height:20px;background:#4950f6;border-radius:100%;transform:translate(-50%,-50%);opacity:.3}.replayer-mouse.active:after{animation:click .2s ease-in-out 1}.replayer-mouse.touch-device{background-image:none;width:70px;height:70px;border-width:4px;border-style:solid;border-radius:100%;margin-left:-37px;margin-top:-37px;border-color:#4950f600;transition:left 0s linear,top 0s linear,border-color .2s ease-in-out}.replayer-mouse.touch-device.touch-active{border-color:#4950f6;transition:left .25s linear,top .25s linear,border-color .2s ease-in-out}.replayer-mouse.touch-device:after{opacity:0}.replayer-mouse.touch-device.active:after{animation:touch-click .2s ease-in-out 1}.replayer-mouse-tail{position:absolute;pointer-events:none}@keyframes click{0%{opacity:.3;width:20px;height:20px}50%{opacity:.5;width:10px;height:10px}}@keyframes touch-click{0%{opacity:0;width:20px;height:20px}50%{opacity:.5;width:10px;height:10px}}:root{--bg: #f4f5fb;--panel: #ffffff;--line: #e1e4f0;--text: #1d2140;--muted: #6b7191;--accent: #ff9f1c;--accent-text: #2b1d00;--primary: #3b4ccf;--primary-text: #fff;--danger: #e0475b;--ok: #1fa971;--radius: 14px;--shadow: 0 6px 24px rgba(29, 33, 64, .08);--canvas-bg: #e9ebf3}*{box-sizing:border-box}html,body{margin:0;background:var(--bg);color:var(--text);font-family:Nunito,Segoe UI,Roboto,Arial,sans-serif;font-size:15px}a{color:var(--primary);text-decoration:none}button,input,select,textarea{font:inherit;color:inherit}h1,h2,h3{margin:0 0 12px;font-weight:800}h1{font-size:28px}h2{font-size:22px}h3{font-size:17px}p{margin:0 0 12px;line-height:1.5}.muted{color:var(--muted)}.small{font-size:13px}.topbar{display:flex;align-items:center;gap:18px;padding:10px 22px;background:var(--panel);border-bottom:1px solid var(--line);position:sticky;top:0;z-index:10}.topbar .brand{font-weight:900;font-size:20px;color:var(--text);letter-spacing:-.3px}.topbar .brand span{color:var(--accent)}.topbar nav{display:flex;gap:14px}.topbar nav a{color:var(--muted);font-weight:700;padding:6px 8px;border-radius:8px}.topbar nav a.active,.topbar nav a:hover{color:var(--text);background:var(--bg)}.topbar .spacer{flex:1}.page{max-width:1180px;margin:0 auto;padding:24px 22px 60px}.btn{display:inline-flex;align-items:center;gap:8px;border:1px solid var(--line);background:var(--panel);border-radius:999px;padding:8px 15px;font-weight:800;cursor:pointer;white-space:nowrap;transition:transform .06s,box-shadow .12s}.btn:hover{box-shadow:var(--shadow)}.btn:active{transform:translateY(1px)}.btn:disabled{opacity:.5;cursor:default;box-shadow:none}.btn.primary{background:var(--primary);color:var(--primary-text);border-color:var(--primary)}.btn.accent{background:var(--accent);color:var(--accent-text);border-color:var(--accent)}.btn.danger{color:var(--danger)}.btn.sm{padding:6px 12px;font-size:13px}.row{display:flex;gap:10px;align-items:center;flex-wrap:wrap}.row.between{justify-content:space-between}.stack{display:flex;flex-direction:column;gap:10px}.field{display:flex;flex-direction:column;gap:6px;margin-bottom:12px}.field label{font-weight:700;font-size:14px}.input,textarea.input,select.input{border:1px solid var(--line);border-radius:10px;padding:8px 12px;background:#fff;outline:none}.input:focus{border-color:var(--primary);box-shadow:0 0 0 3px #3b4ccf1f}.error{color:var(--danger);font-weight:700}.notice{background:#fff7e6;border:1px solid #ffe0a3;border-radius:10px;padding:10px 14px}.card{background:var(--panel);border:1px solid var(--line);border-radius:var(--radius);padding:18px}.grid{display:grid;gap:16px;grid-template-columns:repeat(auto-fill,minmax(240px,1fr))}.tpl-card{display:flex;flex-direction:column;gap:8px;cursor:pointer;transition:box-shadow .12s,transform .12s}.tpl-card:hover{box-shadow:var(--shadow);transform:translateY(-2px)}.fmt-preview{display:grid;place-items:center;height:110px;background:var(--bg);border-radius:10px}.fmt-preview>div{background:#fff;border:1px solid var(--line);box-shadow:0 2px 8px #00000014}.tag{display:inline-block;padding:2px 8px;border-radius:999px;background:var(--bg);color:var(--muted);font-size:12px;font-weight:700}.res-card{display:flex;flex-direction:column;gap:10px}.res-card .title{font-weight:800;font-size:16px}.res-card .actions{display:flex;gap:6px;flex-wrap:wrap}.thumb{width:100%;background:var(--bg);border-radius:10px;overflow:hidden;display:grid;place-items:center;border:1px solid var(--line)}.thumb img{width:100%;height:100%;object-fit:contain;display:block}.thumb-empty{color:var(--muted);font-size:13px;font-weight:700}.hero{padding:60px 0 30px;text-align:center}.hero h1{font-size:40px;line-height:1.15}.hero p{font-size:18px;color:var(--muted);max-width:640px;margin:0 auto 22px}.feats{display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:14px;margin-top:30px}.auth{max-width:420px;margin:40px auto}.modal-bg{position:fixed;inset:0;background:#1d214080;display:grid;place-items:center;z-index:50;padding:20px}.modal{background:var(--panel);border-radius:16px;padding:22px;width:min(720px,100%);max-height:90vh;overflow:auto;box-shadow:var(--shadow)}.code{font-family:ui-monospace,SFMono-Regular,Menlo,monospace;font-size:12px;background:var(--bg);border-radius:8px;padding:10px;white-space:pre-wrap;word-break:break-all}.iconbtn{border:0;background:transparent;color:var(--muted);cursor:pointer;border-radius:8px;width:34px;height:34px;font-size:18px}.iconbtn:hover{background:var(--bg);color:var(--text)}.list{display:flex;flex-direction:column;gap:12px}.title{font-weight:800;font-size:17px}.lesson-row{display:flex;gap:16px;justify-content:space-between;align-items:flex-start;flex-wrap:wrap}.lesson-main{flex:1;min-width:280px;display:flex;flex-direction:column;gap:6px}.link-row{display:flex;gap:8px;align-items:center;flex-wrap:wrap}.code.inline{display:inline-block;padding:4px 8px}.personal{display:flex;gap:6px;flex-wrap:wrap;align-items:center;padding:8px;background:var(--bg);border-radius:10px}.actions{display:flex;gap:6px;flex-wrap:wrap;align-items:center}.drop{border:2px dashed var(--line);border-radius:var(--radius);padding:26px 18px;text-align:center;cursor:pointer;background:var(--panel);margin-bottom:18px}.drop.over{border-color:var(--primary);background:#eef0ff}.history{margin-top:12px;border-top:1px solid var(--line);padding-top:10px}.table{width:100%;border-collapse:collapse;font-size:14px}.table th,.table td{text-align:left;padding:6px 8px;border-bottom:1px solid var(--line)}.table th{color:var(--muted);font-size:12px}.ellipsis{white-space:nowrap;overflow:hidden;text-overflow:ellipsis}.dot{width:9px;height:9px;border-radius:50%;background:#c9cddc;display:inline-block;flex:none}.dot.open{background:var(--ok)}.dot.connecting{background:var(--accent)}.dot.closed{background:var(--danger)}.brand{font-weight:900;font-size:20px;color:var(--text);letter-spacing:-.3px}.brand span{color:var(--accent)}.brand.small{font-size:15px}.join{min-height:100vh;display:grid;place-items:center;padding:20px}.join .auth{margin:0;width:min(440px,100%)}.shell{position:fixed;inset:0;display:grid;grid-template-rows:40px 1fr;background:#fff}.shell-bar{display:flex;align-items:center;gap:12px;padding:0 12px;background:var(--panel);border-bottom:1px solid var(--line)}.shell-title{font-weight:800;white-space:nowrap;overflow:hidden;text-overflow:ellipsis;max-width:40vw}.shell-frame{width:100%;height:100%;border:0;display:block;background:#fff}.room{position:fixed;inset:0;display:grid;grid-template-rows:48px 1fr;grid-template-columns:260px 1fr 320px;background:var(--bg)}.room-top{grid-column:1 / -1;display:flex;align-items:center;gap:10px;padding:0 12px;background:var(--panel);border-bottom:1px solid var(--line)}.room-title{font-size:16px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis;max-width:40vw}.room-list,.room-feed{background:var(--panel);overflow:auto;display:flex;flex-direction:column;min-height:0}.room-list{border-right:1px solid var(--line)}.room-feed{border-left:1px solid var(--line)}.room-list-head{padding:10px 12px;font-weight:800;border-bottom:1px solid var(--line);display:flex;gap:8px;align-items:center;justify-content:space-between;position:sticky;top:0;background:var(--panel)}.stu{text-align:left;border:0;border-bottom:1px solid var(--line);background:transparent;padding:10px 12px;cursor:pointer;display:flex;flex-direction:column;gap:3px}.stu:hover{background:var(--bg)}.stu.on{background:#eef0ff;box-shadow:inset 3px 0 0 var(--primary)}.stu:not(.online) b{color:var(--muted)}.room.nofeed{grid-template-columns:260px 1fr}.room.full{grid-template-rows:1fr;grid-template-columns:1fr}.room.full .room-top,.room.full .room-list,.room-feed.hidden{display:none}.room.full .room-feed{position:fixed;right:0;top:42px;bottom:0;width:340px;z-index:20;box-shadow:var(--shadow)}.room.full .mirror{background:#111}.room-main{display:grid;grid-template-rows:42px 1fr;min-width:0;min-height:0}.room-tools{display:flex;align-items:center;gap:8px;padding:0 12px;background:var(--panel);border-bottom:1px solid var(--line);overflow-x:auto;white-space:nowrap}.room-tools>span:first-child{flex:none}.seg{display:inline-flex;border:1px solid var(--line);border-radius:999px;overflow:hidden}.seg button{border:0;background:transparent;padding:6px 12px;font-weight:700;cursor:pointer;font-size:13px}.seg button.on{background:var(--primary);color:#fff}.mirror{position:relative;overflow:auto;min-height:0;background:var(--canvas-bg);padding:8px}.mirror-stage{position:relative;margin:0 auto;background:#fff;box-shadow:0 8px 30px #1d21402e}.mirror-viewport{position:absolute;left:0;right:0;border:2px dashed rgba(59,76,207,.55);pointer-events:none;box-sizing:border-box}.mirror-viewport span{position:absolute;right:6px;top:4px;background:#3b4ccfd9;color:#fff;font-size:11px;font-weight:700;padding:2px 7px;border-radius:999px}.mirror-host{position:absolute;left:0;top:0}.mirror-host .replayer-wrapper{position:relative}.mirror-host iframe{border:0}.mirror-overlay{position:absolute;inset:0}.mirror-overlay.point{cursor:crosshair}.mirror-overlay.highlight,.mirror-overlay.control{cursor:pointer}.mirror-edit{position:absolute;z-index:5;display:flex;gap:6px;align-items:flex-start;background:var(--panel);border:2px solid var(--primary);border-radius:10px;padding:6px;box-shadow:var(--shadow);min-width:220px}.mirror-edit .input{flex:1;min-width:160px}.mirror-edit textarea.input{min-height:70px}.act-teacher{background:#eef0ff}.mirror-ghost{position:absolute;border:2px solid var(--primary);background:#3b4ccf26;border-radius:6px;pointer-events:none;z-index:4}.mirror-ripple{position:absolute;width:28px;height:28px;margin:-14px 0 0 -14px;border-radius:50%;border:3px solid var(--primary);pointer-events:none;z-index:6;animation:cf-ripple .45s ease-out forwards}@keyframes cf-ripple{0%{transform:scale(.4);opacity:.9}to{transform:scale(1.6);opacity:0}}.mirror-ghost.card.settled{transform:none;opacity:.95;transition:none}.mirror-ghost.card{border:0;background:transparent;border-radius:0;overflow:visible;opacity:.92;filter:drop-shadow(0 10px 22px rgba(29,33,64,.35));transform:rotate(1.5deg)}.mirror-hl{position:absolute;border:3px solid var(--accent);border-radius:8px;pointer-events:none;box-shadow:0 0 0 4px #ff9f1c40}.mirror-empty{position:sticky;height:100%;inset:0;display:grid;place-items:center;color:var(--muted);font-weight:700;pointer-events:none;text-align:center;padding:20px}.feed{flex:1;overflow:auto;padding:6px 0}.act{display:grid;grid-template-columns:42px 22px 1fr;gap:4px;padding:5px 10px;font-size:13px;line-height:1.35;border-bottom:1px solid #f0f1f6}.act .time{color:var(--muted);font-size:11px;padding-top:2px}.act-feedback{background:#fff9e8}.act-report{background:#eafff3}.act-section{color:var(--muted)}@media (max-width: 900px){.room{grid-template-columns:1fr;grid-template-rows:48px auto 1fr auto}.room-list,.room-feed{max-height:30vh}}