/* -- Card component -------------------------------------------- */

@layer components {
  /* Spacing runs through one private variable: --_pad (section padding) =
     --_base (the SIZE's padding, md 1.5rem) × --_k (the DENSITY factor), and
     --_hf (the header→footer gap when no content sits between them) =
     --_hfb × --_kh. Size and density therefore combine instead of fighting.
     --_title / --_desc carry the size's type scale. All private. */
  .card {
    --_base: 1.5rem;
    --_hfb: 1rem;
    --_k: 1;
    --_kh: 1;
    --_pad: calc(var(--_base) * var(--_k));
    --_hf: calc(var(--_hfb) * var(--_kh));
    background-color: var(--card);
    color: var(--card-foreground);
    border: 1px solid var(--border);
    border-radius: var(--radius-xl);
    overflow: hidden;
    container-type: inline-size;
  }

  .card-header {
    display: flex;
    flex-direction: column;
    gap: 0.25rem;
    padding: var(--_pad, 1.5rem);
    padding-bottom: 0;
  }

  .card-title {
    font-size: var(--_title, 1.25rem);
    font-weight: 600;
    line-height: 1.25;
    letter-spacing: -0.01em;
    margin: 0;
  }

  .card-description {
    font-size: var(--_desc, 0.875rem);
    color: var(--muted-foreground);
    margin: 0;
    line-height: 1.6;
  }

  .card-content {
    padding: var(--_pad, 1.5rem);
  }

  .card-footer {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: var(--_pad, 1.5rem);
    padding-top: 0;
  }

  /* Header + footer with no .card-content between: the zeroed paddings would
     glue them together - restore the gap for that composition only. */
  .card-header + .card-footer {
    padding-top: var(--_hf, 1rem);
  }

  /* A header-only card (a title + description panel): the header is the last
     section, so it keeps its bottom padding instead of sitting on the edge. */
  .card-header:last-child {
    padding-bottom: var(--_pad, 1.5rem);
  }

  /* -- Body: an optional wrapper around header / content / footer.
     Needed for the side and overlay layouts (media | body); in a column it
     pushes the footer to the bottom, so a row of cards lines up its actions. */
  .card-body {
    display: flex;
    flex-direction: column;
    min-width: 0;

    & > .card-footer {
      margin-top: auto;
    }
  }

  /* -- Media: a figure (img / video / picture / svg) edge to edge - first
     child for an image on top, last child for one at the bottom. 16:9 unless
     the author sets an aspect-ratio. data-inset pads and rounds it instead
     (the centered-content look). */
  .card-media {
    display: block;
    margin: 0;
    overflow: hidden;
    aspect-ratio: 16 / 9;

    & > :is(img, video, picture, svg) {
      display: block;
      width: 100%;
      height: 100%;
      object-fit: cover;
    }

    &[data-inset] {
      margin: var(--_pad) var(--_pad) 0;
      border-radius: var(--radius-lg);
    }
    &[data-inset]:last-child {
      margin: 0 var(--_pad) var(--_pad);
    }
  }

  /* -- Density --------------------------------------------------
     data-density on the .card root scales the section paddings together.
     Scale matches sizing.css data-density (0.75 / 1 / 1.25): comfortable is
     the unsized default (1.5rem), compact 1rem, spacious 2rem; the
     header+footer-only gap (1rem base) follows the ratio (0.75 / 1 / 1.5). */
  .card:where([data-density="compact"]) {
    --_k: calc(2 / 3);
    --_kh: 0.75;
  }
  .card:where([data-density="comfortable"]) {
    --_k: 1;
    --_kh: 1;
  }
  .card:where([data-density="spacious"]) {
    --_k: calc(4 / 3);
    --_kh: 1.5;
  }

  .card {
    /* -- Sizes: padding + type scale together (md == the default) ----- */
    &[data-size="xs"] {
      --_base: 0.75rem;
      --_hfb: 0.5rem;
      --_title: 0.875rem;
      --_desc: 0.75rem;
    }
    &[data-size="sm"] {
      --_base: 1rem;
      --_hfb: 0.75rem;
      --_title: 1rem;
      --_desc: 0.8125rem;
    }
    &[data-size="md"] {
      --_base: 1.5rem;
      --_hfb: 1rem;
      --_title: 1.25rem;
      --_desc: 0.875rem;
    }
    &[data-size="lg"] {
      --_base: 2rem;
      --_hfb: 1.25rem;
      --_title: 1.5rem;
      --_desc: 1rem;
    }
    &[data-size="xl"] {
      --_base: 2.5rem;
      --_hfb: 1.5rem;
      --_title: 1.875rem;
      --_desc: 1.0625rem;
    }

    /* -- Variants -------------------------------------------------- */
    &[data-variant="outline"] {
      background-color: transparent;
    }
    &[data-variant="dashed"] {
      border-style: dashed;
      border-width: 2px;
    }
    &[data-variant="ghost"] {
      background-color: transparent;
      border-color: transparent;
    }
    &[data-variant="muted"] {
      background-color: var(--muted);
      border-color: transparent;
    }
    &[data-variant="elevated"] {
      border-color: transparent;
      box-shadow: var(--shadow-lg);
    }
    &[data-variant="primary"] {
      background-color: var(--primary);
      color: var(--primary-foreground);
      border-color: transparent;

      & .card-description {
        color: color-mix(in oklch, var(--primary-foreground) 78%, transparent);
      }
    }
    /* a charcoal surface: the inverse colors, softened (78%) so it stays
       apart from --primary - in the default theme primary IS near-black */
    &[data-variant="neutral"] {
      background-color: color-mix(in oklch, var(--foreground) 78%, var(--background));
      color: var(--background);
      border-color: transparent;

      & .card-description {
        color: color-mix(in oklch, var(--background) 72%, transparent);
      }
    }
    /* ghost / link buttons on a colored surface take its text color and a
       hover tint made from it (the default hover - the pale --accent - would
       put near-white text on near-white) */
    &:is([data-variant="primary"], [data-variant="neutral"], [data-layout="overlay"])
      .btn:is([data-variant="ghost"], [data-variant="link"]) {
      color: inherit;

      &:hover {
        background-color: color-mix(in oklch, currentColor 16%, transparent);
        color: inherit;
      }
    }
    /* frosted: translucent card over whatever is behind it */
    &[data-variant="glass"] {
      background-color: color-mix(in oklch, var(--card) 55%, transparent);
      border-color: color-mix(in oklch, var(--foreground) 14%, transparent);
      backdrop-filter: blur(16px) saturate(1.4);
      box-shadow: 0 8px 32px -8px color-mix(in oklch, var(--foreground) 22%, transparent);
    }

    /* -- Centered content ------------------------------------------ */
    &[data-align="center"] {
      text-align: center;

      & .card-header {
        align-items: center;
      }
      & .card-footer {
        justify-content: center;
      }
    }

    /* -- Layouts ---------------------------------------------------
       side: media | body in one row, always (media after the body = image
       on the right). auto: side by side while the CARD is wide enough,
       stacked when it is not - the flex-wrap switch follows the card's own
       width, not the viewport, so the same card works in a sidebar and in a
       wide column. overlay: the media is the background, the body sits on
       a scrim at the bottom. */
    &[data-layout="side"] {
      display: grid;
      grid-template-columns: minmax(0, 2fr) minmax(0, 3fr);

      & > .card-media {
        aspect-ratio: auto;
        min-height: 100%;
      }
    }
    &[data-layout="side"]:has(> .card-body:first-child) {
      grid-template-columns: minmax(0, 3fr) minmax(0, 2fr);
    }
    &[data-layout="auto"] {
      display: flex;
      flex-wrap: wrap;

      & > .card-media {
        flex: 1 1 12rem;
        aspect-ratio: auto;
        min-height: 10rem;
      }
      & > .card-body {
        flex: 999 1 18rem;
      }
    }
    &[data-layout="overlay"] {
      display: grid;
      color: #fff;
      border-color: transparent;

      & > * {
        grid-area: 1 / 1;
      }
      & > .card-media {
        aspect-ratio: auto;
        min-height: 14rem;
      }
      & > .card-body {
        z-index: 1;
        align-self: end;
        background: linear-gradient(to top, oklch(0 0 0 / 0.78), oklch(0 0 0 / 0.35) 65%, transparent);
        padding-top: 3rem;
      }
      & .card-description {
        color: oklch(1 0 0 / 0.82);
      }
    }

    /* -- Interactive: a link (or [data-interactive]) card lifts on hover
       and shows a focus ring on keyboard focus ------------------------ */
    &:is(a, [data-interactive]) {
      display: block;
      text-decoration: none;
      transition:
        translate 150ms ease,
        box-shadow 150ms ease,
        border-color 150ms ease;

      &:hover {
        translate: 0 -2px;
        box-shadow: var(--shadow-md);
        border-color: color-mix(in oklch, var(--foreground) 22%, var(--border));
      }
      &:focus-visible {
        outline: 2px solid var(--ring);
        outline-offset: 2px;
      }
    }
    &:is(a, [data-interactive])[data-layout="auto"] {
      display: flex;
    }
    &:is(a, [data-interactive]):is([data-layout="side"], [data-layout="overlay"]) {
      display: grid;
    }

    /* -- Selectable: a <label class="card"> around a checkbox / radio -
       the checked card takes a primary ring; keyboard focus shows too */
    &:is(label) {
      display: block;
      cursor: pointer;
      transition:
        border-color 150ms ease,
        box-shadow 150ms ease;

      &:has(:is(input[type="checkbox"], input[type="radio"]):checked) {
        border-color: var(--primary);
        box-shadow: 0 0 0 1px var(--primary);
      }
      &:has(input:focus-visible) {
        outline: 2px solid var(--ring);
        outline-offset: 2px;
      }
      &:has(input:disabled) {
        cursor: not-allowed;
        opacity: 0.55;
      }
    }
  }

  /* -- Container query: compact card in narrow containers - unless the
     card asks for a size (an explicit data-size wins) -- */
  @container (max-width: 280px) {
    .card:not([data-size]) :is(.card-header, .card-content, .card-footer) {
      --_pad: 1rem;
    }
    .card:not([data-size]) .card-title {
      font-size: 1rem;
    }
  }

  /* -- Accessibility ------------------------------------------ */
  @media (prefers-reduced-motion: reduce) {
    .card:is(a, [data-interactive]) {
      transition: none;
    }
    .card:is(a, [data-interactive]):hover {
      translate: none;
    }
  }
  @media (forced-colors: active) {
    .card:is(label):has(:is(input[type="checkbox"], input[type="radio"]):checked) {
      border: 2px solid Highlight;
    }
  }
}