:root{--bg: #f2f4f9;--card: #ffffff;--line: #e3e8f0;--text: #1c2333;--muted: #7b8598;--primary: #4f6ef7;--primary-dark: #3d5ae0;--danger: #e5484d;--warn: #f76707;--ok: #12b886;--radius: 14px}*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--text);font-family:Segoe UI,Microsoft YaHei,PingFang SC,system-ui,sans-serif;font-size:15px}h1,h2{margin:0;font-weight:700}h2{font-size:18px;margin-bottom:16px}label{display:block;font-weight:600;margin-bottom:6px;font-size:13px;color:#3a4358}input,textarea,select{width:100%;padding:10px 12px;border:1px solid #d4dbe7;border-radius:10px;font:inherit;background:#fff;outline:none;transition:border-color .15s}input:focus,textarea:focus,select:focus{border-color:var(--primary)}textarea{resize:vertical;min-height:72px}.app{min-height:100vh;display:flex;flex-direction:column}.topbar{display:flex;align-items:center;gap:24px;background:var(--card);border-bottom:1px solid var(--line);padding:0 28px;height:58px;position:sticky;top:0;z-index:10}.brand{display:flex;align-items:center;gap:8px;font-weight:800;font-size:17px}.brand .logo{font-size:20px}.brand .tag{font-size:12px;color:var(--primary);background:#eef1fe;padding:2px 8px;border-radius:999px}.topbar nav{display:flex;gap:4px;flex:1}.topbar nav a{text-decoration:none;color:var(--muted);padding:8px 14px;border-radius:10px;font-weight:600}.topbar nav a.router-link-active{color:var(--primary);background:#eef1fe}.whoami{color:var(--muted);font-size:13px;white-space:nowrap}.main{flex:1;padding:24px 28px;width:100%;max-width:1200px;margin:0 auto}.card{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:22px}.page-grid{display:grid;grid-template-columns:minmax(0,1.6fr) minmax(280px,1fr);gap:20px;align-items:start}.page-narrow{max-width:820px;margin:0 auto}.side{display:flex;flex-direction:column;gap:14px}.side-head{display:flex;align-items:center;justify-content:space-between;margin-bottom:4px}.side-head h2{margin:0}@media(max-width:900px){.page-grid{grid-template-columns:1fr}}.field{margin-bottom:18px}.field.row{display:flex;align-items:center;gap:12px}.field.row label{margin:0;white-space:nowrap}.field.row select{width:160px}.row-gap{display:flex;gap:10px;align-items:center}.row-gap select{width:auto}.muted{color:var(--muted);font-size:13px}.center{text-align:center}.ellipsis{overflow:hidden;text-overflow:ellipsis;white-space:nowrap;max-width:180px}.btn{display:inline-flex;align-items:center;justify-content:center;gap:6px;border:1px solid #d4dbe7;background:#fff;color:var(--text);border-radius:10px;padding:9px 16px;font:inherit;font-weight:600;cursor:pointer;transition:all .15s;text-decoration:none}.btn:hover{border-color:var(--primary);color:var(--primary)}.btn:disabled{opacity:.5;cursor:not-allowed}.btn.primary{background:var(--primary);border-color:var(--primary);color:#fff}.btn.primary:hover{background:var(--primary-dark)}.btn.danger{color:var(--danger);border-color:#f3c2c4}.btn.danger:hover{background:#fdf0f0;border-color:var(--danger)}.btn.warn{color:var(--warn);border-color:#f8d3b0}.btn.warn:hover{background:#fff4ec;border-color:var(--warn)}.btn.ghost{border-color:transparent;background:transparent}.btn.ghost:hover{background:#eef1f7}.btn.small{padding:6px 12px;font-size:13px}.btn.big{padding:13px 20px;font-size:16px}.btn.block{width:100%}.icon-btn{border:none;background:#f0f3f9;border-radius:8px;width:28px;height:28px;cursor:pointer;color:var(--muted);font-size:13px}.icon-btn:hover{background:#e4e9f3;color:var(--text)}.icon-btn.danger:hover{background:#fdeaea;color:var(--danger)}.icon-btn:disabled{opacity:.35;cursor:not-allowed}.chips{display:flex;flex-wrap:wrap;gap:8px}.chip{border:1.5px solid #d4dbe7;background:#fff;border-radius:999px;padding:7px 16px;font:inherit;font-weight:600;cursor:pointer;color:var(--muted);transition:all .15s}.chip.on{background:var(--primary);border-color:var(--primary);color:#fff}.items{display:flex;flex-direction:column;gap:12px;margin-bottom:10px}.item{border:1px solid var(--line);border-radius:12px;padding:12px 14px;background:#fbfcfe}.item-head{display:flex;align-items:center;gap:8px;margin-bottom:10px}.item-idx{color:var(--muted);font-size:12px}.spacer{flex:1}.badge{font-size:12px;font-weight:700;padding:2px 10px;border-radius:999px;color:#fff}.badge.text{background:var(--primary)}.badge.image{background:var(--ok)}.badge.audio{background:var(--warn)}.badge.room{background:#5c677d}.uploading{color:var(--muted);padding:8px 0;font-size:13px}.thumb{max-width:100%;max-height:160px;border-radius:10px;display:block;margin-bottom:8px}.audio{width:100%;margin-bottom:8px}.file-row{display:flex;align-items:center;gap:10px}.add-row{display:flex;gap:10px}.status{padding:16px 18px}.status-head{display:flex;align-items:center;justify-content:space-between;margin-bottom:8px}.room-name{font-weight:800}.status-title{font-weight:700;margin-bottom:4px}.status-sum{color:#3a4358;font-size:13px;margin-bottom:6px}.status-meta{color:var(--muted);font-size:12px}.history-item{display:flex;align-items:center;gap:16px;border-top:1px solid var(--line);padding:14px 2px}.history-item:first-of-type{border-top:none}.history-main{flex:1;min-width:0}.history-title{font-weight:700;margin-bottom:4px;display:flex;align-items:center;gap:8px}.login-wrap{min-height:100vh;display:flex;align-items:center;justify-content:center;background:linear-gradient(160deg,#eef1fe,#f2f4f9 45%,#e7fbf4)}.login-card{width:360px;background:var(--card);border:1px solid var(--line);border-radius:18px;padding:36px 32px;text-align:center;box-shadow:0 12px 40px #1c233314}.login-logo{font-size:40px}.login-card h1{font-size:22px;margin:8px 0 2px}.login-card .sub{color:var(--muted);margin:0 0 22px}.login-card input{margin-bottom:10px;text-align:center}.err{color:var(--danger);font-size:13px;margin:4px 0 10px}.toasts{position:fixed;top:70px;left:50%;transform:translate(-50%);display:flex;flex-direction:column;gap:8px;z-index:100;align-items:center}.toast{background:#223;color:#fff;padding:10px 20px;border-radius:999px;font-size:14px;box-shadow:0 6px 24px #0000002e;animation:pop .2s ease-out}.toast.err{background:var(--danger)}.toast.ok{background:#1f2b4d}@keyframes pop{0%{opacity:0;transform:translateY(-8px)}}.pwd-row{display:grid;grid-template-columns:1fr 1fr;gap:12px}.add-teacher{display:grid;grid-template-columns:1fr 1fr;gap:10px;margin-bottom:18px}.add-teacher input{width:100%}.add-teacher .btn{grid-column:1 / -1}.teacher-item{display:flex;align-items:center;gap:14px;border-top:1px solid var(--line);padding:12px 2px}.teacher-main{flex:1;min-width:0}.teacher-name{font-weight:700;display:flex;align-items:center;gap:8px;flex-wrap:wrap}.teacher-actions{display:flex;gap:8px;flex:none}@media(max-width:720px){input,textarea,select{font-size:16px;padding:11px 12px}.topbar{padding:0 12px;gap:8px;height:52px}.brand .name{display:none}.brand .logo{font-size:18px}.topbar nav{gap:2px;flex:1}.topbar nav a{padding:8px 10px;font-size:14px}.whoami{display:none}.topbar .btn.ghost{padding:7px 10px;font-size:13px}.main{padding:14px 12px 28px}.card{padding:16px;border-radius:12px}.page-grid{grid-template-columns:1fr;gap:14px}.page-narrow{padding:0}h2{font-size:17px}.btn{padding:10px 14px}.btn.small{padding:8px 12px}.btn.big{padding:14px 18px;font-size:16px}.add-row .btn{flex:1}.file-row,.item-head{flex-wrap:wrap}.field.row{flex-wrap:wrap;gap:8px}.field.row select{width:100%}.side-head{flex-wrap:wrap;gap:8px}.status{padding:14px}.history-item{flex-direction:column;align-items:stretch;gap:10px}.history-item>.btn{width:100%}.pwd-row,.add-teacher{grid-template-columns:1fr}.teacher-item{flex-wrap:wrap}.teacher-actions{width:100%}.teacher-actions .btn{flex:1}.login-wrap{padding:16px}.login-card{width:100%;max-width:400px;padding:28px 22px}.toasts{top:60px;width:calc(100vw - 24px)}.toast{max-width:100%;font-size:13px;padding:9px 16px}}@media(max-width:720px)and (min-width:481px){.add-teacher{grid-template-columns:1fr 1fr}.add-teacher .btn{grid-column:1 / -1}.pwd-row{grid-template-columns:1fr 1fr}}