:root {
  /* 单纯控制颜色 */
  --layout-bg-color: #252748;
}

/* 定义背景图的解决方案 */
.layout-group .layout-bg {
  background: url(./bg.jpg) var(--layout-bg-color) no-repeat 100% 100% !important;
}

@media screen and (max-width: 1024px) {
  .layout-group .layout-bg {
    background-image: none !important;
  }
}