:root{--bg:#f3f6fb;--card:#fff;--ink:#142033;--muted:#65758b;--line:#dfe6ef;--brand:#174ea6;--brand2:#2367d1;--danger:#b52b2b;--ok:#168257;--shadow:0 18px 55px rgba(28,49,82,.11);--radius:22px}*{box-sizing:border-box}html,body{margin:0;min-height:100%;font-family:Inter,ui-sans-serif,system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;color:var(--ink);background:radial-gradient(circle at 0 0,#e6efff 0,transparent 35%),var(--bg)}button,input,select,textarea{font:inherit}.hidden{display:none!important}.shell{max-width:1440px;margin:0 auto;padding:28px}.card{background:rgba(255,255,255,.95);border:1px solid rgba(214,225,239,.9);box-shadow:var(--shadow);border-radius:var(--radius)}.brand{display:flex;align-items:center;gap:12px}.brand strong,.brand small{display:block}.brand small{color:var(--muted);font-size:.78rem;margin-top:2px}.brand-mark{display:grid;place-items:center;width:42px;height:42px;border-radius:13px;background:linear-gradient(145deg,var(--brand2),var(--brand));color:#fff;font-weight:800;font-size:1.25rem;box-shadow:0 8px 20px rgba(23,78,166,.25)}.brand.compact .brand-mark{width:36px;height:36px}.gate{width:min(620px,100%);margin:7vh auto;padding:34px}.gate-copy{padding:44px 0 24px}.eyebrow{font-size:.72rem;font-weight:800;letter-spacing:.14em;color:var(--brand)}h1,h2,p{margin-top:0}.gate h1{font-size:clamp(2.05rem,5vw,3.4rem);line-height:1.02;letter-spacing:-.04em;margin:12px 0 18px}.gate-copy p{color:var(--muted);line-height:1.6;max-width:52ch}.stack{display:grid;gap:15px}label{display:grid;gap:7px;font-size:.86rem;font-weight:700;color:#314259}input,select,textarea{width:100%;border:1px solid var(--line);background:#fbfcfe;border-radius:12px;padding:12px 13px;color:var(--ink);outline:none;transition:.18s}input:focus,select:focus,textarea:focus{border-color:#7ba7e8;box-shadow:0 0 0 4px rgba(35,103,209,.10);background:#fff}button{border:0;border-radius:12px;padding:12px 16px;font-weight:800;cursor:pointer;transition:.16s}button:disabled{opacity:.55;cursor:not-allowed}.primary{background:linear-gradient(135deg,var(--brand2),var(--brand));color:#fff;box-shadow:0 8px 20px rgba(23,78,166,.22)}.primary:hover{transform:translateY(-1px)}.secondary{background:#eaf1fb;color:#194c94}.ghost{background:transparent;border:1px solid var(--line);color:#43546a}.danger{color:var(--danger)}.large{min-height:48px}.error{color:var(--danger);font-size:.85rem;min-height:1.2em}.muted{color:var(--muted);line-height:1.5}.mini{font-size:.78rem}.topbar{display:flex;justify-content:space-between;align-items:center;margin-bottom:20px}.session-meta{display:flex;gap:8px;flex-wrap:wrap}.chip{padding:8px 11px;background:#fff;border:1px solid var(--line);border-radius:999px;font-size:.78rem;font-weight:700}.chip.status{color:#7d5d00}.workspace{display:grid;grid-template-columns:340px minmax(0,1fr);gap:20px}.side{padding:24px;display:flex;flex-direction:column;gap:15px;max-height:calc(100vh - 110px);overflow:auto}.side h2{margin:8px 0}.divider{height:1px;background:var(--line);margin:2px 0}.upload{border:1px dashed #94b3de;border-radius:15px;padding:14px;background:#f7faff;color:var(--brand);cursor:pointer}.upload input{display:none}.upload span,.upload small{display:block}.upload small{color:var(--muted);font-weight:500;margin-top:4px}.doc-list{display:grid;gap:7px}.doc{padding:10px 11px;border:1px solid var(--line);border-radius:11px;background:#fbfcfe}.doc strong,.doc small{display:block;overflow:hidden;text-overflow:ellipsis}.doc small{color:var(--muted);margin-top:3px}.check{grid-template-columns:auto 1fr;align-items:start}.check input{width:auto;margin-top:3px}.settings-actions{display:grid;grid-template-columns:1fr 1fr;gap:8px}.conversation{min-height:calc(100vh - 110px);padding:25px;display:grid;grid-template-rows:auto auto minmax(210px,1fr);gap:18px}.teacher-stage{text-align:center;padding:12px 10px 4px}.teacher-stage h1{font-size:1.7rem;margin:10px 0 5px}.teacher-stage p{color:var(--muted);margin-bottom:0}.avatar{width:190px;height:190px;margin:0 auto;position:relative;display:grid;place-items:center}.avatar svg{width:160px;height:160px;position:relative;z-index:2;filter:drop-shadow(0 12px 18px rgba(28,49,82,.16))}.halo{position:absolute;inset:13px;border-radius:50%;background:radial-gradient(circle,#dfeaff,transparent 66%)}.speech-ring{position:absolute;inset:17px;border:2px solid rgba(35,103,209,.15);border-radius:50%}.avatar.speaking .speech-ring{animation:pulse 1.15s infinite}.avatar.speaking{animation:floaty 2.4s ease-in-out infinite}.avatar-bg{fill:#eaf2ff}.face{fill:#f0c6a6}.hair{fill:#293343}.shirt{fill:#174ea6}.eye{fill:#273240}.mouth,.brow{stroke:#5d3a2c;stroke-width:4;fill:none;stroke-linecap:round}.brow{stroke-width:3}.right{opacity:.9}.avatar.speaking .mouth{animation:mouth .36s infinite alternate;transform-origin:center}.teacher-state{display:flex;align-items:center;justify-content:center;gap:7px;font-size:.8rem;color:var(--muted)}.dot{width:8px;height:8px;border-radius:50%;background:#9aa6b3}.dot.active{background:var(--ok);box-shadow:0 0 0 5px rgba(22,130,87,.1)}.controls{display:flex;justify-content:center;gap:10px;flex-wrap:wrap}.transcript-wrap{border:1px solid var(--line);border-radius:16px;overflow:hidden;display:grid;grid-template-rows:auto 1fr;min-height:220px}.transcript-head{display:flex;justify-content:space-between;gap:10px;padding:12px 15px;border-bottom:1px solid var(--line);background:#f9fbfe}.transcript{overflow:auto;padding:16px;display:flex;flex-direction:column;gap:10px}.empty{color:#8795a8;text-align:center;margin:auto}.turn{max-width:82%;padding:10px 12px;border-radius:14px;line-height:1.48;font-size:.92rem}.turn.user{align-self:flex-end;background:#e9f1ff;border-bottom-right-radius:5px}.turn.agent{align-self:flex-start;background:#f0f3f7;border-bottom-left-radius:5px}.turn small{display:block;font-size:.68rem;color:#758398;margin-bottom:4px;font-weight:800;text-transform:uppercase;letter-spacing:.06em}@keyframes pulse{0%{transform:scale(.98);opacity:.3}50%{transform:scale(1.08);opacity:.75}100%{transform:scale(.98);opacity:.3}}@keyframes floaty{50%{transform:translateY(-3px)}}@keyframes mouth{to{transform:scaleY(1.55)}}@media(max-width:900px){.shell{padding:14px}.workspace{grid-template-columns:1fr}.side{max-height:none}.conversation{min-height:720px}.side{order:2}.conversation{order:1}}@media(max-width:520px){.gate{margin:1vh auto;padding:24px}.workspace{gap:14px}.conversation{padding:15px}.side{padding:18px}.avatar{width:150px;height:150px}.avatar svg{width:132px;height:132px}.turn{max-width:94%}.topbar .brand small{display:none}.session-meta .chip:first-child{display:none}}