:root{--bg:#0e0f13;--panel:#16181f;--border:#262932;--text:#e7e9ee;--muted:#9aa0ad;--accent:#4f8cff;--user:#1d2230}*{box-sizing:border-box}body,html{margin:0;height:100%;background:var(--bg);color:var(--text);font-family:ui-sans-serif,system-ui,-apple-system,Segoe UI,Roboto,sans-serif;font-size:15px}.app{display:grid;grid-template-columns:260px 1fr;height:100vh}.sidebar{border-right:1px solid var(--border);background:var(--panel);display:flex;flex-direction:column;overflow:hidden}.sidebar header{padding:16px;border-bottom:1px solid var(--border);font-weight:600}.new-btn{margin:12px;padding:9px 12px;border-radius:8px;cursor:pointer;background:var(--accent);color:#fff;border:none;font-weight:600}.admin-link{margin:0 12px 8px;font-size:13px;color:var(--muted);text-decoration:none;display:inline-block}.admin-link:hover{color:var(--accent)}.session-list{overflow-y:auto;flex:1 1;padding:0 8px 8px}.session{padding:9px 10px;border-radius:7px;cursor:pointer;color:var(--muted);white-space:nowrap;overflow:hidden;text-overflow:ellipsis;font-size:14px}.session:hover{background:#1b1e27;color:var(--text)}.session.active{background:#222634;color:var(--text)}.main{display:flex;flex-direction:column;overflow:hidden}.thread{flex:1 1;overflow-y:auto;padding:24px;display:flex;flex-direction:column;gap:16px}.msg{max-width:760px;line-height:1.55;white-space:pre-wrap;word-wrap:break-word}.msg.user{align-self:flex-end;background:var(--user);padding:10px 14px;border-radius:12px}.msg.assistant{align-self:flex-start}.tool-chip{display:inline-block;font-size:12px;color:var(--muted);background:#1b1e27;border:1px solid var(--border);border-radius:999px;padding:3px 10px;margin:4px 0}.composer{border-top:1px solid var(--border);padding:14px 24px;display:flex;gap:10px}.composer textarea{flex:1 1;resize:none;background:var(--panel);color:var(--text);border:1px solid var(--border);border-radius:10px;padding:11px 13px;font:inherit;min-height:46px;max-height:200px}.composer button{background:var(--accent);color:#fff;border:none;border-radius:10px;padding:0 18px;font-weight:600;cursor:pointer}.composer button:disabled{opacity:.5;cursor:default}.center{display:grid;place-items:center;height:100vh}.card{background:var(--panel);border:1px solid var(--border);border-radius:14px;padding:28px;width:340px}.card h1{margin:0 0 6px;font-size:18px}.card p{color:var(--muted);margin:0 0 18px;font-size:14px}.card input{width:100%;background:var(--bg);color:var(--text);border:1px solid var(--border);border-radius:9px;padding:10px 12px;font:inherit;margin-bottom:10px}.card button{width:100%;background:var(--accent);color:#fff;border:none;border-radius:9px;padding:10px;font-weight:600;cursor:pointer}.error{color:#ff6b6b;font-size:13px;margin-top:8px}