:root {
  --bg: #0f1115;
  --panel: #171a21;
  --panel-2: #1f242d;
  --border: #2a2f3a;
  --text: #e6e8ee;
  --muted: #8a93a6;
  --accent: #4f8cff;
  --accent-hover: #6ba0ff;
  --user: #2a3a5a;
  --assistant: #1f242d;
  --error: #ff6b6b;
}
* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; height: 100%; background: var(--bg); color: var(--text); font: 15px/1.5 -apple-system, Segoe UI, Roboto, Arial, sans-serif; }
body { display: flex; flex-direction: column; height: 100vh; }

.topbar { display: flex; justify-content: space-between; align-items: center; padding: 12px 20px; background: var(--panel); border-bottom: 1px solid var(--border); }
.topbar .actions { display: flex; gap: 8px; }

button { background: var(--accent); color: #fff; border: 0; padding: 8px 14px; border-radius: 6px; cursor: pointer; font-size: 14px; }
button:hover { background: var(--accent-hover); }
button.ghost { background: transparent; border: 1px solid var(--border); color: var(--muted); }
button.ghost:hover { color: var(--text); border-color: var(--muted); }

.chat { flex: 1; overflow-y: auto; padding: 20px; display: flex; flex-direction: column; gap: 14px; max-width: 900px; width: 100%; margin: 0 auto; }
.msg { padding: 12px 16px; border-radius: 10px; white-space: pre-wrap; word-wrap: break-word; }
.msg.user { background: var(--user); align-self: flex-end; max-width: 80%; }
.msg.assistant { background: var(--assistant); align-self: flex-start; max-width: 95%; border: 1px solid var(--border); }
.msg .role { font-size: 11px; color: var(--muted); text-transform: uppercase; letter-spacing: .5px; margin-bottom: 4px; }
.welcome { text-align: center; padding: 24px; }
.muted { color: var(--muted); }

.composer { display: flex; gap: 8px; padding: 12px 20px; background: var(--panel); border-top: 1px solid var(--border); max-width: 900px; width: 100%; margin: 0 auto; }
.composer textarea { flex: 1; background: var(--panel-2); color: var(--text); border: 1px solid var(--border); border-radius: 6px; padding: 10px 12px; resize: none; font: inherit; }
.composer textarea:focus { outline: none; border-color: var(--accent); }

.login-body { display: flex; align-items: center; justify-content: center; }
.login-card { background: var(--panel); padding: 32px; border-radius: 10px; border: 1px solid var(--border); width: 360px; max-width: 92vw; }
.login-card h1 { margin: 0 0 4px; font-size: 22px; }
.login-card form { display: flex; flex-direction: column; gap: 10px; margin-top: 20px; }
.login-card label { font-size: 13px; color: var(--muted); }
.login-card input { background: var(--panel-2); color: var(--text); border: 1px solid var(--border); border-radius: 6px; padding: 10px 12px; font: inherit; }
.login-card input:focus { outline: none; border-color: var(--accent); }
.error { color: var(--error); font-size: 13px; margin: 4px 0 0; }