@layer base {
  html {
    font-size: 16px;
    /* Sticky 48px header must not cover anchor targets. */
    scroll-padding-top: 4rem;
  }

  body {
    font-family: var(--font-sans);
    font-size: 1rem;
    line-height: 1.6;
    background-color: var(--bg-primary);
    color: var(--text-primary);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
  }

  main {
    flex: 1;
  }

  /* -- Headings ------------------------------------------------------------
     Sized by role in components rather than by tag, so the tag can stay
     semantically correct without dragging a display size along with it.
     ------------------------------------------------------------------------ */

  h1,
  h2,
  h3,
  h4,
  h5,
  h6 {
    font-weight: 600;
    line-height: 1.25;
    letter-spacing: -0.01em;
    text-wrap: balance;
  }

  p {
    text-wrap: pretty;
  }

  strong,
  b {
    font-weight: 600;
    color: var(--text-primary);
  }

  code,
  kbd,
  samp,
  pre {
    font-family: var(--font-mono);
  }

  /* -- Focus ---------------------------------------------------------------
     One visible ring everywhere. Never removed, only restyled.
     ------------------------------------------------------------------------ */

  :focus-visible {
    outline: 2px solid var(--accent);
    outline-offset: 2px;
    border-radius: 1px;
  }

  /* Elements that already sit flush against a rule get an inset ring so the
     outline is not clipped by the neighbouring cell. */
  .tab:focus-visible,
  .demo-tab:focus-visible,
  .grid-cell:focus-visible {
    outline-offset: -2px;
  }

  ::selection {
    background: var(--accent);
    color: var(--accent-contrast);
  }

  /* -- Skip link ------------------------------------------------------------ */

  .skip-link {
    position: absolute;
    top: -100%;
    left: 1rem;
    z-index: 200;
    padding: 0.5rem 1rem;
    background: var(--accent);
    color: var(--accent-contrast);
    font-size: 0.85rem;
    font-weight: 600;
    border-radius: 0 0 var(--radius-lg) var(--radius-lg);
  }

  .skip-link:focus {
    top: 0;
  }

  /* -- Shared inline atoms -------------------------------------------------- */

  .mono {
    font-family: var(--font-mono);
  }

  .visually-hidden {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip-path: inset(50%);
    white-space: nowrap;
    border: 0;
  }
}