app/node_modules/@angular/material/list/_list-item-hcm-indicator.scss

@use '@angular/cdk';

// Renders a circle indicator when Windows Hich Constrast mode (HCM) is enabled. In some
// situations, such as a selected option, the list item communicates the selected state by changing
// its background color. Since that doesn't work in HCM, this mixin provides an alternative by
// rendering a circle.
@mixin private-high-contrast-list-item-indicator() {
  @include cdk.high-contrast {
    &::after {
      $size: 10px;
      content: '';
      position: absolute;
      top: 50%;
      right: 16px;
      transform: translateY(-50%);
      width: $size;
      height: 0;
      border-bottom: solid $size;
      border-radius: $size;
    }

    [dir='rtl'] {
      &::after {
        right: auto;
        left: 16px;
      }
    }
  }
}