*{box-sizing:border-box}body{color:#1f1f1f;background-color:#fff;margin:0;font-family:system-ui,-apple-system,BlinkMacSystemFont,Segoe UI,sans-serif}button,input{font:inherit}.app{place-items:center;min-height:100vh;padding:24px;display:grid}.chat-shell{background:#fff;border-radius:16px;grid-template-rows:auto 1fr auto;width:min(100%,900px);min-height:640px;display:grid;overflow:hidden}.chat-header{border-bottom:1px solid #eee;padding:20px 24px}.chat-header h1{margin:0;font-size:22px}.chat-header p{color:#777;margin:6px 0 0;font-size:14px}.chat-body{min-height:0;overflow-y:auto}.chat-empty{text-align:center;place-items:center;padding:32px;display:grid}.logo{color:#fff;background-color:#111;border-radius:16px;place-items:center;width:56px;height:56px;font-size:24px;font-weight:700;display:grid}.chat-empty h2{margin:22px 0 0;font-size:30px}.chat-empty p{color:#666;width:min(100%,520px);margin:12px 0 0;line-height:1.7}.message-list{gap:18px;padding:24px;display:grid}.message{grid-template-columns:36px minmax(0,1fr);align-items:start;gap:12px;display:grid}.message-user{grid-template-columns:minmax(0,1fr) 36px}.message-user .message-avatar{color:#155fc2;background-color:#e9f2ff;grid-column:2}.message-user .message-content{background-color:#f3f3f3;border-radius:18px;grid-area:1/1;justify-self:end;max-width:min(100%,680px);padding:12px 16px}.message-avatar{color:#fff;background-color:#111;border-radius:50%;place-items:center;width:36px;height:36px;font-size:14px;font-weight:700;display:grid}.message-content{overflow-wrap:anywhere;min-width:0;line-height:1.7}.chat-input{border-top:1px solid #eee;grid-template-columns:1fr auto;gap:12px;padding:18px 24px;display:grid}.chat-input input{border:1px solid #ddd;border-radius:999px;outline:none;min-width:0;padding:12px 16px}.chat-input button{color:#fff;cursor:pointer;background-color:#111;border:0;border-radius:999px;padding:0 20px}.chat-input input:disabled{color:#999;background:#f7f7f7}.chat-input button:disabled{cursor:not-allowed;background:#d7d7d7}