picocss/scss/components/_dropdown.scss

@use "sass:map";
@use "../settings" as *;

@if map.get($modules, "components/dropdown") and $enable-classes {
  /**
   * Dropdown (details.dropdown)
   */

  // Container
  // ––––––––––––––––––––
  #{$parent-selector} details.dropdown {
    position: relative;
    border-bottom: none;

    @if $enable-transitions {
      &[open] {
        > summary,
        > button,
        > a {
          &::after {
            transform: rotate(0deg);
          }
        }
      }
    }

    // Marker
    // ––––––––––––––––––––
    > summary,
    > button,
    > a {
      &::after {
        display: block;
        width: 1rem;
        height: calc(1rem * var(#{$css-var-prefix}line-height, 1.5));
        margin-inline-start: 0.25rem;
        float: right;
        // TODO: find out why we need this magic number (0.2 rem)
        // for the marker to be aligned with the regular select
        //transform: rotate(0deg) translateX(0.2rem);
        transform: rotate(-90deg);
        background-image: var(#{$css-var-prefix}icon-chevron);
        background-position: right center;
        background-size: 1rem auto;
        background-repeat: no-repeat;
        content: "";
      }
    }

    // Button as a select
    // inside container type accordion
    // ––––––––––––––––––––
    > summary {
      &:not([role]) {
        height: calc(
          1rem *
            var(#{$css-var-prefix}line-height) +
            var(#{$css-var-prefix}form-element-spacing-vertical) *
            2 +
            var(#{$css-var-prefix}border-width) *
            2
        );
        padding: var(#{$css-var-prefix}form-element-spacing-vertical)
          var(#{$css-var-prefix}form-element-spacing-horizontal);
        border: var(#{$css-var-prefix}border-width)
          solid
          var(#{$css-var-prefix}form-element-border-color);
        border-radius: var(#{$css-var-prefix}border-radius);
        background-color: var(#{$css-var-prefix}form-element-background-color);
        color: var(#{$css-var-prefix}form-element-placeholder-color);
        line-height: inherit;
        cursor: pointer;
        user-select: none;

        @if $enable-transitions {
          transition:
            background-color var(#{$css-var-prefix}transition),
            border-color var(#{$css-var-prefix}transition),
            color var(#{$css-var-prefix}transition),
            box-shadow var(#{$css-var-prefix}transition);
        }

        &:active,
        &:focus {
          border-color: var(#{$css-var-prefix}form-element-active-border-color);
          background-color: var(#{$css-var-prefix}form-element-active-background-color);
        }

        &:focus {
          box-shadow: 0
            0
            0
            var(#{$css-var-prefix}outline-width)
            var(#{$css-var-prefix}form-element-focus-color);
        }

        // Reset focus visible from accordion component
        &:focus-visible {
          outline: none;
        }

        // Aria-invalid
        &[aria-invalid="false"] {
          #{$css-var-prefix}form-element-border-color: var(
            #{$css-var-prefix}form-element-valid-border-color
          );
          #{$css-var-prefix}form-element-active-border-color: var(
            #{$css-var-prefix}form-element-valid-focus-color
          );
          #{$css-var-prefix}form-element-focus-color: var(
            #{$css-var-prefix}form-element-valid-focus-color
          );
        }

        &[aria-invalid="true"] {
          #{$css-var-prefix}form-element-border-color: var(
            #{$css-var-prefix}form-element-invalid-border-color
          );
          #{$css-var-prefix}form-element-active-border-color: var(
            #{$css-var-prefix}form-element-invalid-focus-color
          );
          #{$css-var-prefix}form-element-focus-color: var(
            #{$css-var-prefix}form-element-invalid-focus-color
          );
        }
      }

      // Submenu
      // ––––––––––––––––––––
      + ul {
        display: flex;
        z-index: 99;
        position: absolute;
        left: 0;
        flex-direction: column;
        width: 100%;
        min-width: fit-content;
        margin: 0;
        margin-top: var(#{$css-var-prefix}outline-width);
        padding: 0;
        border: var(#{$css-var-prefix}border-width)
          solid
          var(#{$css-var-prefix}dropdown-border-color);
        border-radius: var(#{$css-var-prefix}border-radius);
        background-color: var(#{$css-var-prefix}dropdown-background-color);
        box-shadow: var(#{$css-var-prefix}dropdown-box-shadow);
        color: var(#{$css-var-prefix}dropdown-color);
        white-space: nowrap;
        opacity: 0;

        @if $enable-transitions {
          transition:
            opacity var(#{$css-var-prefix}transition),
            transform 0s ease-in-out 1s;
        }

        &[dir="rtl"] {
          right: 0;
          left: auto;
        }

        li {
          width: 100%;
          margin-bottom: 0;
          padding: calc(var(#{$css-var-prefix}form-element-spacing-vertical) * 0.5)
            var(#{$css-var-prefix}form-element-spacing-horizontal);
          list-style: none;

          &:first-of-type {
            margin-top: calc(var(#{$css-var-prefix}form-element-spacing-vertical) * 0.5);
          }

          &:last-of-type {
            margin-bottom: calc(var(#{$css-var-prefix}form-element-spacing-vertical) * 0.5);
          }

          details {
            margin-bottom: 0;

            > summary {
              line-height: var(#{$css-var-prefix}line-height);
            }
          }

          a {
            display: block;
            margin: calc(var(#{$css-var-prefix}form-element-spacing-vertical) * -0.5)
              calc(var(#{$css-var-prefix}form-element-spacing-horizontal) * -1);
            padding: calc(var(#{$css-var-prefix}form-element-spacing-vertical) * 0.5)
              var(#{$css-var-prefix}form-element-spacing-horizontal);
            overflow: hidden;
            border-radius: 0;
            color: var(#{$css-var-prefix}dropdown-color);
            text-decoration: none;
            text-overflow: ellipsis;

            &:hover,
            &:focus,
            &:active,
            &:focus-visible,
            &[aria-current]:not([aria-current="false"]) {
              background-color: var(#{$css-var-prefix}dropdown-hover-background-color);
            }
          }

          label {
            width: 100%;
          }

          // Not working in Firefox, which doesn't support the `:has()` pseudo-class
          &:has(label):hover {
            background-color: var(#{$css-var-prefix}dropdown-hover-background-color);
          }
        }
      }
    }

    // Menu opened
    // ––––––––––––––––––––
    // 1. Inside container type accordion
    &[open] > summary {
      // Button opened
      // inside container type accordion
      // ––––––––––––––––––––
      margin-bottom: 0;

      // Close for dropdown
      // inside container type accordion
      // ––––––––––––––––––––
      &::before {
        display: block;
        z-index: 1;
        position: fixed;
        width: 100vw;
        height: 100vh;
        inset: 0;
        background: none;
        content: "";
        cursor: default;
      }

      + ul {
        transform: scaleY(1);
        opacity: 1;

        @if $enable-transitions {
          transition:
            opacity var(#{$css-var-prefix}transition),
            transform 0s ease-in-out 0s;
        }
      }
    }
  }

  // Container type accordion
  // inside a nav
  // ––––––––––––––––––––
  // Dropdown inside a nav
  // ––––––––––––––––––––
  #{$parent-selector} nav details.dropdown {
    display: inline;
    margin: calc(var(#{$css-var-prefix}nav-element-spacing-vertical) * -1) 0;
    // Override height
    margin-bottom: 0;

    > summary {
      &:not([role]) {
        // Override height
        height: calc(
          (1rem * var(#{$css-var-prefix}line-height)) +
            (var(#{$css-var-prefix}nav-link-spacing-vertical) * 2)
        );
        padding: calc(
            var(#{$css-var-prefix}nav-link-spacing-vertical) -
              (var(#{$css-var-prefix}border-width) * 2)
          )
          var(#{$css-var-prefix}nav-link-spacing-horizontal);

        &:focus-visible {
          box-shadow: 0
            0
            0
            var(#{$css-var-prefix}outline-width)
            var(#{$css-var-prefix}primary-focus);
        }
      }
    }
  }

  // Label
  // ––––––––––––––––––––
  #{$parent-selector} label > details.dropdown {
    margin-top: calc(var(#{$css-var-prefix}spacing) * 0.25);
  }
}