*, *::before, *::after { box-sizing: border-box; }
html, body, #app { height: 100%; margin: 0; padding: 0; }
html, body { overflow-x: hidden; }
body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Helvetica, Arial, sans-serif;
  background: #f5f7fa;
  color: #303133;
  -webkit-font-smoothing: antialiased;
}
/* 加载时占位，避免白屏 */
.__boot {
  display: flex; align-items: center; justify-content: center;
  height: 100%; color: #909399; font-size: 14px;
}