/**
 * Fluid Framework - Step Indicator Component
 * @layer components
 *
 * Discrete labeled steps for multi-step forms and onboarding flows.
 *
 * Usage:
 *   <nav class="steps" aria-label="Progress">
 *     <ol class="steps__list">
 *       <li class="steps__item" data-status="complete">
 *         <span class="steps__marker">1</span>
 *         <span class="steps__label">Account</span>
 *       </li>
 *       <li class="steps__item" data-status="current" aria-current="step">
 *         <span class="steps__marker">2</span>
 *         <span class="steps__label">Details</span>
 *       </li>
 *       <li class="steps__item">
 *         <span class="steps__marker">3</span>
 *         <span class="steps__label">Review</span>
 *       </li>
 *     </ol>
 *   </nav>
 *
 * Statuses: data-status="complete|current" (default: upcoming)
 * Variants: data-size="sm"
 */

@layer components {
  .steps__list {
    display: flex;
    align-items: flex-start;
    gap: 0;
    list-style: none;
    padding: 0;
    margin: 0;
    counter-reset: step;
  }

  .steps__item {
    --_steps-marker: 2.5rem;
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--space-2);
    position: relative;
    text-align: center;
    margin: 0;
  }

  /* Connector line between steps: half on each side of the boundary, so
     neither half leaves its own item (visual-scan TEXT, 2026-10-29). */
  .steps__item:not(:last-child)::after,
  .steps__item:not(:first-child)::before {
    content: "";
    position: absolute;
    inset-block-start: calc(var(--_steps-marker) / 2 - 1px);
    block-size: 2px;
    background: var(--color-border);
    z-index: 0;
  }

  .steps__item:not(:last-child)::after {
    inset-inline: calc(50% + var(--_steps-marker) / 2 + 0.25rem) 0;
  }

  .steps__item:not(:first-child)::before {
    inset-inline: 0 calc(50% + var(--_steps-marker) / 2 + 0.25rem);
  }

  .steps__item[data-status="complete"]:not(:last-child)::after,
  .steps__item[data-status="complete"] + .steps__item::before {
    background: var(--accent);
  }

  /* Step marker (circle) */
  .steps__marker {
    display: flex;
    align-items: center;
    justify-content: center;
    inline-size: var(--_steps-marker);
    block-size: var(--_steps-marker);
    border-radius: var(--radius-full);
    border: var(--border-width-thick) solid var(--color-border);
    background: var(--color-background);
    font-size: var(--font-size-sm);
    font-weight: var(--weight-semibold);
    color: var(--color-text-muted);
    position: relative;
    z-index: var(--z-raised);
    transition:
      background-color var(--duration-normal) var(--ease-fluid),
      border-color var(--duration-normal) var(--ease-fluid),
      color var(--duration-normal) var(--ease-fluid);
  }

  /* Current step */
  .steps__item[data-status="current"] .steps__marker {
    border-color: var(--accent);
    background: var(--accent);
    color: var(--on-accent);
    box-shadow: 0 0 0 3px var(--accent-subtle);
  }

  /* Completed step */
  .steps__item[data-status="complete"] .steps__marker {
    border-color: var(--accent);
    background: var(--accent);
    color: var(--on-accent);
  }

  /* Checkmark for completed steps */
  .steps__item[data-status="complete"] .steps__marker::after {
    content: "✓";
    font-size: var(--font-size-base);
  }

  /* Hide the number text when showing checkmark */
  .steps__item[data-status="complete"] .steps__marker {
    font-size: 0;
  }

  .steps__item[data-status="complete"] .steps__marker::after {
    font-size: var(--font-size-base);
  }

  /* Step label */
  .steps__label {
    font-size: var(--font-size-sm);
    color: var(--color-text-muted);
    font-weight: var(--weight-medium);
  }

  .steps__item[data-status="current"] .steps__label {
    color: var(--color-text);
    font-weight: var(--weight-semibold);
  }

  .steps__item[data-status="complete"] .steps__label {
    color: var(--color-text);
  }


  /* ========================================
     SMALL VARIANT
     ======================================== */

  .steps[data-size="sm"] .steps__item { --_steps-marker: 1.75rem; }

  .steps[data-size="sm"] .steps__marker {
    font-size: var(--font-size-xs);
  }

  .steps[data-size="sm"] .steps__label {
    font-size: var(--font-size-xs);
  }


  /* ========================================
     RESPONSIVE
     ======================================== */

  @media (max-width: 40rem) {
    .steps__label {
      font-size: var(--font-size-xs);
    }

    .steps__item:not(.steps[data-size="sm"] *) { --_steps-marker: 2rem; }

    .steps__marker {
      font-size: var(--font-size-xs);
    }
  }



  /* ========================================
     REDUCED MOTION
     ======================================== */

  @media (prefers-reduced-motion: reduce) {
    .steps__marker {
      transition: none;
    }
  }
}