*{box-sizing:border-box}body{margin:0;font-family:-apple-system,BlinkMacSystemFont,"PingFang SC","Microsoft YaHei",sans-serif;background:#f7f7f8}.app{display:flex;flex-direction:column;height:100vh;max-width:900px;margin:0 auto;background:#fff}.header{padding:16px 20px;border-bottom:1px solid #eee;font-weight:600}.chat{flex:1;overflow:auto;padding:20px;background:#f7f7f8}.row{display:flex;margin-bottom:16px}.row.user{justify-content:flex-end}.bubble{max-width:75%;padding:12px 16px;border-radius:16px;line-height:1.7;white-space:pre-wrap;word-break:break-word}.user .bubble{background:#07c160;color:#fff;border-bottom-right-radius:6px}.assistant .bubble{background:#fff;border:1px solid #e5e5e5;border-bottom-left-radius:6px}.footer{display:flex;gap:10px;padding:12px;border-top:1px solid #eee;background:#fff}#input{flex:1;resize:none;height:56px;padding:14px 16px;border:1px solid #ddd;border-radius:14px;font:inherit}#send{width:72px;border:none;border-radius:14px;background:#07c160;color:#fff;font:inherit;cursor:pointer}#send:disabled{opacity:.6;cursor:not-allowed}