element-plus/packages/theme-chalk/src/option-group.scss

@use 'sass:map';

@use 'mixins/mixins' as *;
@use 'common/var' as *;

@include b(select-group) {
  $gap: 20px;

  margin: 0;
  padding: 0;

  @include e(wrap) {
    position: relative;
    list-style: none;
    margin: 0;
    padding: 0;

    &:not(:last-of-type) {
      padding-bottom: 24px;

      &::after {
        content: '';
        position: absolute;
        display: block;
        left: $gap;
        right: $gap;
        bottom: 12px;
        height: 1px;
        background: var(--el-border-color-light);
      }
    }
  }

  @include e(split) {
    &-dash {
      position: absolute;
      left: $gap;
      right: $gap;
      height: 1px;
      background: var(--el-border-color-light);
    }
  }

  @include e(title) {
    padding-left: $gap;
    font-size: map.get($select-group, 'font-size');
    color: map.get($select-group, 'text-color');
    line-height: map.get($select-group, 'height');
  }

  & .#{$namespace}-select-dropdown__item {
    padding-left: $gap;
  }
}