:root{--bg: #0f1419;--surface: #1a2332;--surface2: #243044;--border: #2d3f56;--text: #e8eef7;--muted: #8fa3bf;--accent: #3d9cf5;--accent-dim: #2a6fad;--user-bg: #1e3a5f;--assistant-bg: #1a2838;--danger: #f07178;--ok: #7fd99a;--radius: 10px;font-family:IBM Plex Sans,system-ui,sans-serif}*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--text);min-height:100vh}a{color:var(--accent)}.loading-screen{display:grid;place-items:center;min-height:100vh;color:var(--muted)}.auth-layout{min-height:100vh;display:grid;place-items:center;padding:24px;background:radial-gradient(ellipse at top,#1a2a40 0%,var(--bg) 55%)}.auth-card{width:min(420px,100%);background:var(--surface);border:1px solid var(--border);border-radius:16px;padding:28px}.brand{display:flex;gap:14px;align-items:center;margin-bottom:20px}.brand h1{margin:0;font-size:1.25rem}.brand p{margin:4px 0 0;color:var(--muted);font-size:.85rem}.brand-mark{width:44px;height:44px;border-radius:12px;background:linear-gradient(135deg,var(--accent),#6b4ce6);display:grid;place-items:center;font-weight:700;font-size:1.2rem}.brand-mark.sm{width:32px;height:32px;font-size:1rem}.tabs{display:flex;gap:8px;margin-bottom:20px}.tabs button{flex:1;padding:10px;border:1px solid var(--border);background:transparent;color:var(--muted);border-radius:var(--radius);cursor:pointer}.tabs button.active{background:var(--surface2);color:var(--text);border-color:var(--accent-dim)}label{display:block;margin-bottom:14px;font-size:.85rem;color:var(--muted)}input,textarea{width:100%;margin-top:6px;padding:10px 12px;border-radius:var(--radius);border:1px solid var(--border);background:var(--bg);color:var(--text);font:inherit}textarea{resize:vertical}.btn-primary{background:var(--accent);color:#fff;border:none;padding:10px 18px;border-radius:var(--radius);font-weight:600;cursor:pointer}.btn-primary:disabled{opacity:.5;cursor:not-allowed}.btn-primary.full{width:100%;margin:12px;width:calc(100% - 24px)}.btn-secondary{background:var(--surface2);color:var(--text);border:1px solid var(--border);padding:8px 14px;border-radius:var(--radius);cursor:pointer}.error{color:var(--danger);font-size:.9rem}.success{color:var(--ok)}.app-shell{display:grid;grid-template-columns:280px 1fr;height:100vh}.sidebar{background:var(--surface);border-right:1px solid var(--border);display:flex;flex-direction:column}.sidebar-header{display:flex;align-items:center;gap:10px;padding:16px;border-bottom:1px solid var(--border)}.chat-list{flex:1;overflow-y:auto;padding:8px}.chat-item{width:100%;text-align:left;display:flex;justify-content:space-between;align-items:center;gap:8px;padding:10px 12px;margin-bottom:4px;border:none;border-radius:var(--radius);background:transparent;color:var(--text);cursor:pointer}.chat-item span:first-child{overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.chat-item.active{background:var(--surface2)}.delete-chat{color:var(--muted);padding:0 4px}.delete-chat:hover{color:var(--danger)}.sidebar-footer{padding:14px 16px;border-top:1px solid var(--border);display:flex;flex-wrap:wrap;gap:10px;align-items:center;font-size:.85rem;color:var(--muted)}.link-muted{color:var(--muted);text-decoration:none}.link-btn{background:none;border:none;color:var(--accent);cursor:pointer;padding:0}.chat-main{display:flex;flex-direction:column;min-height:0}.empty-state{flex:1;display:grid;place-content:center;text-align:center;gap:12px;color:var(--muted)}.messages{flex:1;overflow-y:auto;padding:24px;display:flex;flex-direction:column;gap:16px}.msg{max-width:820px;padding:14px 16px;border-radius:12px;line-height:1.55}.msg header{font-size:.75rem;text-transform:uppercase;letter-spacing:.05em;color:var(--muted);margin-bottom:8px}.msg-user{align-self:flex-end;background:var(--user-bg)}.msg-assistant{align-self:flex-start;background:var(--assistant-bg);border:1px solid var(--border)}.msg-assistant pre{background:var(--bg);padding:12px;border-radius:8px;overflow-x:auto;font-family:JetBrains Mono,monospace;font-size:.85rem}.composer{display:flex;gap:12px;padding:16px 24px 24px;border-top:1px solid var(--border);background:var(--surface)}.composer textarea{flex:1}.error.banner{margin:0 24px;padding:10px;background:#f071781f;border-radius:var(--radius)}.admin-page{max-width:960px;margin:0 auto;padding:32px 24px 64px}.admin-header{display:flex;justify-content:space-between;align-items:center;margin-bottom:24px}.admin-card{background:var(--surface);border:1px solid var(--border);border-radius:14px;padding:20px 24px;margin-bottom:20px}.admin-form{display:grid;gap:12px;max-width:480px}.status-pill{display:inline-block;padding:6px 12px;border-radius:999px;font-weight:600;margin-bottom:8px}.status-pill.ok{background:#7fd99a26;color:var(--ok)}.status-pill.err{background:#f0717826;color:var(--danger)}.muted{color:var(--muted);font-size:.9rem}.users-table{width:100%;border-collapse:collapse;font-size:.9rem}.users-table th,.users-table td{text-align:left;padding:10px 8px;border-bottom:1px solid var(--border)}@media (max-width: 768px){.app-shell{grid-template-columns:1fr}.sidebar{display:none}}