zyAdmin/node_modules/vxe-pc-ui/styles/components/layout-header.scss

.vxe-layout-header {
  flex-shrink: 0;
  background-color: var(--vxe-ui-layout-background-color);
  outline: 0;
  &.is--fixed {
    position: sticky;
    top: 0;
    left: 0;
    z-index: 9;
  }
}