fizzy/app/assets/stylesheets/popup.css

@layer components {
  .popup {
    --panel-border-radius: 0.5em;
    --panel-padding: var(--block-space);
    --panel-size: auto;

    inset: 0 auto auto 50%;
    max-block-size: 80vh;
    min-inline-size: min(25ch, calc(100dvw - var(--block-space-double)));
    max-inline-size: min(55ch, calc(100dvw - var(--block-space-double)));
    overflow: auto;
    position: absolute;
    transform: translateX(-50%);
    z-index: var(--z-popup);

    &[open] {
      display: flex;
    }

    &.orient-left {
      inset-inline: auto 0;
      transform: translateX(0);
    }

    &.orient-right {
      inset-inline: 0 auto;
      transform: translateX(0);
    }

    &:has(.popup__footer) {
      --panel-padding: var(--block-space) var(--block-space) 0 var(--block-space);
    }

    #header:has(&) {
      max-inline-size: 100vw;
      position: relative;
      z-index: 5;
    }

    .card & {
      min-inline-size: 25ch;
      max-inline-size: 25ch;
    }
  }

  .popup__footer {
    background-color: var(--color-canvas);
    border-block-start: 1px solid var(--color-ink-lighter);
    font-size: var(--text-small);
    inset: auto 0 0;
    line-height: 1.6;
    margin-block-start: var(--block-space-half);
    padding: 1.5ch;
    position: sticky;
    text-align: center;
    z-index: 1;
  }

  .popup__group {
    align-items: center;
    background: transparent;
    border-radius: 0.3em;
    display: flex;
    inline-size: 100%;
    max-inline-size: 100%;

    .popup__list &:has(*:first-child:not(.popup__item)) {
      padding-inline-start: var(--inline-space-half);
    }

    .btn {
      --btn-background: transparent;
    }

    @media (any-hover: hover) {
      &:hover {
        background: var(--color-ink-lightest);
      }
    }

    &[aria-selected] {
      background-color: var(--color-selected);

      @media (any-hover: hover) {
        &:hover {
          background-color: var(--color-selected);
        }
      }
    }
  }

  .popup__list {
    display: flex;
    flex-direction: column;
    inline-size: 100%;
    list-style: none;
    margin: 0;
    max-inline-size: 100%;
    padding: 0;
    row-gap: 2px;

    /* Hide lists when all the items within are hidden */
    &:has(.popup__group-title:only-child),
    &:has(.popup__group[hidden]):not(:has(.popup__group:not([hidden]))) {
      display: none;
    }
  }

  .popup__item {
    --btn-background: transparent;
    --btn-border-radius: 0.3em;
    --btn-border-size: 0;
    --btn-font-weight: 500;
    --btn-padding: var(--inline-space-half) var(--inline-space);

    flex: 1 1 auto;
    justify-content: start;
    inline-size: 100%;
    min-inline-size: 0;
    max-inline-size: 100%;
    text-align: start;

    @media (any-hover: hover) {
      &:where(:not(:active):hover) {
        --btn-background: var(--color-selected);
      }
    }

    .icon {
      block-size: 1em;
      inline-size: 1em;
    }

    &:has(input:checked)  {
      --btn-background: transparent;
      --btn-color: var(--color-ink);

      .icon.checked {
        display: block;
      }

      @media (any-hover: hover) {
        &:where(:not(:active):hover) {
          --btn-background: var(--color-selected);
        }
      }
    }
  }

  .popup__new {
    --btn-icon-size: 1em;

    padding-inline-start: var(--inline-space-half);

    .icon {
      margin-inline-end: 0.5em;
    }
  }

  .popup__title {
    font-weight: 800;
  }

  .popup__group-title {
    background: var(--color-canvas);
    font-size: var(--text-small);
    font-weight: bold;
    padding: var(--block-space-half) var(--inline-space-half);
    position: sticky;
    text-transform: uppercase;
    top: calc(-1 * var(--block-space));
    z-index: 1;
  }

  .popup--animated {
    opacity: 0;
    transform: scale(0.2) translateX(-50%);
    transform-origin: top left;
    transition: var(--dialog-duration) allow-discrete;
    transition-property: display, opacity, overlay, transform;

    &::backdrop {
      background-color: var(--color-always-black);
      opacity: 0;
      transform: scale(1);
      transition: var(--dialog-duration) allow-discrete;
      transition-property: display, opacity, overlay;
    }

    /* Safari doesn't position the sticky footer properly during the
     * transition, so we need to delay the footer entrance. */
    .popup__footer {
      animation: safari-sticky-footer-hack 0s;
      animation-delay: var(--dialog-duration);
      animation-fill-mode: both;
      inset-inline: var(--block-space);
    }

    &[open] {
      opacity: 1;
      transform: scale(1) translateX(-50%);

      &::backdrop {
        opacity: 0.5;
      }
    }

    @starting-style {
      &[open] {
        opacity: 0;
        transform: scale(0.2) translateX(-50%);
      }

      &[open]::backdrop {
        opacity: 0;
      }
    }
  }

  @keyframes safari-sticky-footer-hack {
    0% { position: absolute; }
    100% { position: sticky; }
  }
}