:root{color-scheme:dark}body{margin:0;font-family:system-ui,-apple-system,Segoe UI,Roboto,sans-serif;background:#0b0f14;color:#e8edf3}.container{max-width:720px;margin:0 auto;padding:16px}.card{background:#111826;border:1px solid #1f2a3a;border-radius:12px;padding:12px}.row{display:flex;gap:12px;align-items:center}.button{user-select:none;-webkit-user-select:none;background:#2b6cb0;border:none;color:#fff;padding:14px 16px;border-radius:14px;font-size:16px}.button:active{background:#225a93}.button.secondary{background:#334155}.msg{padding:10px 12px;border-radius:12px;margin:10px 0}.msg.user{background:#0f172a;border:1px solid #1f2a3a}.msg.assistant{background:#0b2a1b;border:1px solid #134e2f}.small{opacity:.75;font-size:12px}input{width:100%;padding:10px;border-radius:10px;border:1px solid #1f2a3a;background:#0f172a;color:#e8edf3}