:root{color:#172033;background:#f5f7fb;font-family:Inter,ui-sans-serif,system-ui}body{margin:0}.shell{grid-template-columns:320px 1fr;min-height:100vh;display:grid}.sidebar{color:#fff;background:#111827;flex-direction:column;gap:14px;padding:28px;display:flex}.sidebar h1{margin:0 0 12px;font-size:28px}.search{color:#cbd5e1;background:#1f2937;border-radius:8px;align-items:center;gap:10px;padding:12px;display:flex}.sidebar button{text-align:left;color:#fff;background:0 0;border:0;border-radius:8px;justify-content:space-between;padding:14px;font-size:16px;display:flex}.sidebar button.active,.sidebar button:hover{background:#334155}.sidebar small{color:#93c5fd}.chat{flex-direction:column;gap:24px;padding:28px;display:flex}header{background:#fff;border:1px solid #e5e7eb;border-radius:8px;justify-content:space-between;align-items:center;padding:18px 20px;display:flex}header p{color:#64748b;margin:0}header h2{margin:4px 0 0}.secure{color:#047857;align-items:center;gap:8px;display:flex}.messages{flex-direction:column;flex:1;gap:16px;display:flex}.messages article{background:#fff;border:1px solid #e5e7eb;border-radius:8px;gap:12px;max-width:620px;padding:18px;display:flex;box-shadow:0 10px 30px #0f172a0f}.messages article.mine{color:#fff;background:#2563eb;align-self:flex-end}form{background:#fff;border:1px solid #e5e7eb;border-radius:8px;gap:12px;padding:12px;display:flex}input{border:0;outline:0;flex:1;font-size:16px}form button{color:#fff;background:#111827;border:0;border-radius:8px;align-items:center;gap:8px;padding:12px 18px;display:flex}@media (width<=800px){.shell{grid-template-columns:1fr}.sidebar{min-height:auto}.chat{padding:16px}}