:root{--primary:#1677ff;--primary-dark:#0f5fd1;--bg:#f5f7fb;--card:#fff;--text:#1f2329;--sub:#6b7280;--border:#e5e7eb;--success:#16a34a;--warning:#f59e0b;--danger:#ef4444;--shadow:0 8px 24px #0f172a14;--radius:16px}*{box-sizing:border-box}body{max-width:750px;color:var(--text);-webkit-user-select:none;user-select:none;-webkit-touch-callout:none;background:#f4f8fc;margin:0 auto;font-family:-apple-system,BlinkMacSystemFont,PingFang SC,Microsoft YaHei,Noto Sans SC,sans-serif}img{pointer-events:none;-webkit-user-drag:none}.bubble,input,textarea{-webkit-user-select:text;user-select:text;-webkit-touch-callout:default}.app{background:var(--bg);position:relative}