discourse/app/assets/stylesheets/common/select-kit/dropdown-select-box.scss

.select-kit {
  &.single-select {
    &.dropdown-select-box {
      display: inline-flex;
      min-width: auto;
      border: none;

      &.is-expanded {
        .select-kit-collection,
        .select-kit-body {
          border-radius: 0;
        }
      }

      .select-kit-body {
        border: 1px solid var(--primary-low);
        background-clip: padding-box;
        box-shadow: shadow("dropdown");
      }

      .select-kit-row {
        margin: 0;

        .icons {
          display: flex;
          align-self: flex-start;
          margin-right: 0.5em;

          .d-icon {
            flex: 0 0 100%;
            overflow: hidden;
            font-size: $font-up-2;
            margin-right: 0;
          }
        }

        .texts {
          line-height: $line-height-medium;
          flex: 1 1 0%;
          align-items: flex-start;
          display: flex;
          flex-wrap: wrap;
          flex-direction: column;

          .name {
            flex: 1 1 auto;
            font-weight: bold;
            font-size: $font-0;
            color: var(--primary);
            padding: 0;
            @include ellipsis;
            max-width: 100%;
          }

          .desc {
            flex: 1 1 auto;
            font-size: $font-down-1;
            font-weight: normal;
            color: var(--primary-medium);
            white-space: normal;
          }
        }
      }

      .select-kit-collection {
        padding: 0;
        max-height: 100%;
      }

      .select-kit-header {
        display: inline-flex;
        align-items: center;
        justify-content: space-between;
        flex-direction: row;

        .d-icon + .d-icon {
          margin-left: 0.25em;
        }

        &.is-focused {
          outline-style: auto;
          outline-color: var(--tertiary);
        }
      }
    }
  }
  &.user-notifications-dropdown {
    .select-kit-header .d-icon {
      margin-left: 0;
    }
    .select-kit-header-wrapper {
      justify-content: center;
    }
  }
}