*{box-sizing:border-box;margin:0;padding:0}body{background:#f5f7fa;font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,sans-serif}#app{min-height:100vh;position:relative}.offline-banner{color:#fff;text-align:center;z-index:999;background:#ff9800;justify-content:center;align-items:center;gap:8px;padding:6px 12px;font-size:13px;display:flex;position:sticky;top:0}.offline-banner .van-icon{font-size:16px}