web/assets/css/categories.scss

---
---
/*!
  Style for Tab Categories
  v2.0
  https://github.com/cotes2020/jekyll-theme-chirpy
  © 2019 Cotes Chung
  MIT License
*/

.categories {
  margin-bottom: 2rem;
}

.categories .card-header {
  padding-right: 12px;
}

.categories .card-header>span>i:first-child,
.categories .list-group-item>i {
  color: gray;
}

.categories .list-group-item {
  border-left: none;
  border-right: none;
  padding-left: 2rem;
}

.categories .collapsing .list-group-item:first-child,
.categories .collapse .list-group-item:first-child {
  border-top-left-radius: 0;
  border-top-right-radius: 0;
}

.categories i.far,
.categories i.fas { // fontawesome icons
  font-size: 86%;
}

.category-trigger {
  width: 1.7rem;
  height: 1.7rem;
  border-radius: 50%;
  text-align: center;
  color: #6c757d!important;
}

@media (hover: hover) { // only works on desktop
  .category-trigger:hover {
    background-color: var(--categories-hover-bg, #e9ecef);
  }
}

.category-trigger>i.fas {
  position: relative;
  height: .7rem;
  width: 1rem;
  transition: 300ms ease all;
}

.rotate {
  -ms-transform: rotate(-90deg); /* IE 9 */
  -webkit-transform: rotate(-90deg); /* Safari 3-8 */
  transform: rotate(-90deg);
}

@media (prefers-color-scheme: dark) {
  .categories.card,
  .list-group-item {
    background-color: var(--card-bg);
  }

  .categories .card-header {
    background-color: var(--card-header-bg);
  }

  .categories .list-group-item {
    border-left: none;
    border-right: none;
    padding-left: 2rem;
    border-color: var(--main-border);
  }

  .categories .list-group-item:last-child {
    border-bottom-color: var(--card-bg);
  }
}