discourse/app/assets/stylesheets/mobile/components/topic-footer-mobile-dropdown.scss

.select-kit {
  &.combo-box {
    &.topic-footer-mobile-dropdown {
      .select-kit-row {
        .svg-icon-title {
          margin-right: 0.5em;
        }
        &.bookmarked {
          .d-icon {
            color: $tertiary;
          }
        }
      }

      .select-kit-collection {
        max-height: 100%;
      }
    }
  }
}