:root{font-family:Inter,system-ui,sans-serif}body{margin:0;background:#0f172a;color:#e2e8f0}.container{max-width:420px;margin:60px auto}.layout{display:grid;grid-template-columns:260px 1fr;height:100vh}aside{border-right:1px solid #334155;padding:12px;display:flex;flex-direction:column;gap:8px}section{display:flex;flex-direction:column}header{padding:12px;border-bottom:1px solid #334155}.messages{flex:1;overflow:auto;padding:12px;display:flex;flex-direction:column;gap:8px}.panel,.inline{display:flex;gap:8px}input,button{background:#1e293b;border:1px solid #334155;color:#f8fafc;padding:8px;border-radius:8px}button.active{background:#2563eb;border-color:#2563eb}article{background:#1e293b;padding:8px;border-radius:8px}