discourse/app/assets/stylesheets/common/base/sidebar.scss

:root {
  --d-sidebar-width: #{$d-sidebar-width};
  @include breakpoint(large) {
    --d-sidebar-width: #{$d-sidebar-narrow-width};
  }
  --d-sidebar-animation-time: 0.25s;
  --d-sidebar-animation-ease: ease-in-out;
  // 1.25rem gets text left-aligned with the hamburger icon
  --d-sidebar-row-horizontal-padding: 1rem;
  // ems so height is variable along with font size
  --d-sidebar-row-height: 2.2em;

  --d-sidebar-background: var(--secondary);
  --d-sidebar-admin-background: var(--primary-very-low);
  --d-sidebar-prefix-background: var(
    --primary-low
  ); // example: chat participant count

  --d-sidebar-header-color: var(--primary);
  --d-sidebar-header-icon-color: var(--primary-medium);

  --d-sidebar-link-color: var(--primary-high);
  --d-sidebar-link-icon-color: var(--primary-500);
  --d-sidebar-link-badge-color: var(--primary-700); // example: new count

  --d-sidebar-highlight-background: var(--primary-low);
  --d-sidebar-highlight-color: var(--primary-high);
  --d-sidebar-highlight-prefix-background: var(--primary-300);
  --d-sidebar-highlight-hover-background: var(
    --primary-medium
  ); // example: hovering a button within a highlighted section
  --d-sidebar-highlight-hover-icon: var(
    --primary-very-low
  ); // example: hovering a button within a highlighted section
}

.sidebar-row {
  box-sizing: border-box;
  height: var(--d-sidebar-row-height);
  padding: 0 var(--d-sidebar-row-horizontal-padding);
  align-items: center;
}

.sidebar-wrapper {
  display: flex;
  grid-area: sidebar;
  position: sticky;
  top: var(--main-outlet-offset);
  background: var(--d-sidebar-background);

  @include unselectable;

  // 1dvh with fallback for old browsers
  --1dvh: 1vh;
  @supports (height: 1dvh) {
    --1dvh: 1dvh;
  }

  height: calc(
    var(--composer-vh, var(--1dvh)) * 100 - var(--main-outlet-offset, 0px)
  );

  align-self: start;
  overflow-y: auto;

  .sidebar-container {
    display: flex;
    flex-direction: column;
    box-sizing: border-box;
    height: 100%;
    width: 100%;
    padding: 0;
    border-right: 1px solid var(--primary-low);
    overflow-x: hidden;
    // allows sidebar to scroll to the bottom when the composer is open
    height: calc(100% - var(--composer-height, 0px));
  }

  .sidebar-sections {
    display: flex;
    flex-direction: column;
    box-sizing: border-box;
    flex: 1;
    padding: 1.5rem 1rem 1rem;
    overflow-x: hidden;
    overflow-y: overlay;

    > .sidebar-section-wrapper:last-child {
      border-bottom: 0;
    }

    // custom scrollbar styling
    --scrollbarBg: transparent;
    --scrollbarThumbBg: var(--primary-low);
    --scrollbarWidth: 0.5em;

    scrollbar-color: transparent var(--scrollbarBg);
    transition: scrollbar-color 0.25s ease-in-out;
    transition-delay: 0.5s;

    &::-webkit-scrollbar {
      width: var(--scrollbarWidth);
    }

    &::-webkit-scrollbar-thumb {
      background-color: transparent;
      border-radius: calc(var(--scrollbarWidth) / 2);
    }

    &::-webkit-scrollbar-track {
      background-color: transparent;
    }

    &:hover {
      scrollbar-color: var(--scrollbarThumbBg) var(--scrollbarBg);

      &::-webkit-scrollbar-thumb {
        background-color: var(--scrollbarThumbBg);
      }

      transition-delay: 0s;
    }

    &__back-to-forum {
      color: var(--d-sidebar-link-color);
      display: flex;
      align-items: center;
      svg {
        margin-right: var(--d-sidebar-section-link-prefix-margin-right);
        height: 0.75em;
        width: 0.75em;
        color: var(--d-sidebar-link-icon-color);
      }
    }
  }
}

.sidebar-section-form-modal {
  .draggable {
    display: flex;
    height: 100%;
    width: 100%;
    justify-content: center;
    align-items: center;
    color: var(--primary-medium);
    align-self: center;
    margin-left: auto;
    margin-right: auto;
    cursor: move;
    -webkit-user-drag: element;
  }
  .dragging {
    opacity: 0.4;
  }
  form {
    margin-bottom: 0;
  }
  .input-group input {
    width: 100%;
    margin-bottom: 0;
  }
  input.warning {
    border: 1px solid var(--danger);
  }
  .icon.warning,
  .value.warning {
    position: absolute;
  }
  .sidebar-section-form__input-wrapper {
    margin-bottom: 1em;

    input {
      width: 100%;
    }
  }

  .row-wrapper {
    display: grid;
    grid-template-columns: 2em 4.5em repeat(2, 1fr) 2em;
    padding: 0.55em 0 0.7em;
    -webkit-user-drag: none;
    user-drag: none;
    cursor: default;
    border-top: 2px solid transparent;
    border-bottom: 2px solid transparent;
    margin-bottom: -2px;

    &.header {
      padding-bottom: 0;

      label {
        margin-bottom: 0;
      }
    }

    &.drag-above {
      border-top: 2px solid var(--tertiary);
    }
    &.drag-below {
      border-bottom: 2px solid var(--tertiary);
    }
    .link-icon {
      grid-column: 2;
    }

    .input-group {
      margin: 0 0.5em;
      @include breakpoint(mobile-large) {
        margin: 0 0.25em;
      }
    }
  }

  .always-public-tooltip {
    padding-right: 0.5rem;
  }

  .btn-flat.add-link {
    margin-top: 0.5em;
    margin-left: -0.5em;
    &:active,
    &:focus {
      background: none;
    }
    svg {
      color: var(--tertiary);
      width: 0.75em;
      height: 0.75em;
    }
    &:hover svg {
      color: var(--tertiary-hover);
    }
  }
  .d-modal__footer {
    display: grid;
    grid-template-columns: auto 1fr auto;
    gap: 0.5em 1em;
    @include breakpoint(mobile-extra-large) {
      grid-template-columns: auto 1fr;
      justify-items: left;
      .mark-public-wrapper {
        grid-row: 1;
        grid-column: 1 / span 2;
      }
      .checkbox-label {
        padding: 0 0 0.5em 0;
      }
    }
    .reset-link,
    .delete {
      margin: 0;
      justify-self: right;
    }
    .mark-public-wrapper {
      &.-disabled label {
        cursor: not-allowed;
      }
      .checkbox-label {
        margin: 0;
      }
    }
  }
  .select-kit.multi-select .multi-select-header .formatted-selection {
    display: none;
  }
  .select-kit.is-expanded .select-kit-body {
    min-width: 220px;
  }
  .reset-link {
    margin-right: 0;
    .discourse-no-touch & {
      &:hover {
        .d-icon {
          color: var(--tertiary-hover);
        }
      }
    }
    .d-icon {
      font-size: var(--font-down-1);
      color: var(--tertiary);
    }
  }
  .delete-link {
    .d-icon {
      color: var(--primary-medium);
    }
    .discourse-no-touch & {
      &:hover {
        .d-icon {
          color: var(--danger);
        }
      }
    }
  }
}

.sidebar__panel-switch-button {
  margin: 1em 1.3em 0 1.3em;
  &:last-of-type {
    margin-bottom: 1em;
  }
}

.sidebar-filter {
  margin-top: 1em;
  margin-bottom: 1em;
  border: 1px solid var(--primary-400);
  border-radius: var(--d-input-border-radius);
  background: var(--secondary);
  width: calc(
    var(--d-sidebar-width) - 2 * var(--d-sidebar-row-horizontal-padding)
  );

  &:focus-within {
    border-color: var(--tertiary);
    outline: 1px solid var(--tertiary);
    outline-offset: -1px;
  }

  &__input-container {
    position: relative;
    display: flex;
    align-items: center;
    background: var(--secondary);
    border-radius: var(--d-input-border-radius);
  }

  &__shortcut-hint {
    background-color: rgba(var(--tertiary-rgb), 0.1);
    padding: 0.25em 0.5em;
    margin-right: 0.5em;
    font-size: var(--font-down-3);
    color: var(--primary-medium);
  }

  &__input[type="text"] {
    border: 0;
    background: none;
    margin-bottom: 0;
    width: 50px;
    height: 2em;
    &:focus-within {
      outline: 0;
    }
    width: 100%;
  }

  &__clear {
    width: 2em;
    height: 2em;
    color: var(--primary-medium);
    background-color: var(--secondary);
  }
}

.sidebar-no-results {
  margin: 0.5em var(--d-sidebar-row-horizontal-padding) 0
    var(--d-sidebar-row-horizontal-padding);
  &__title {
    font-weight: bold;
  }
}
.sidebar-no-results {
  display: block;
}

.sidebar-panel-header__row {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  color: var(--d-sidebar-link-color);
  width: calc(
    var(--d-sidebar-width) * var(--d-sidebar-row-horizontal-padding) + 2px
  );
}

.sidebar-toggle-all-sections.btn-transparent {
  padding-right: 0;
  color: var(--d-sidebar-link-color);
  svg {
    width: 0.75em;
    height: 0.85em;
  }
}