---
interface Props {
  headings: { depth: number; slug: string; text: string }[];
}

const { headings } = Astro.props;
---

<details class="toc">
  <summary class="toc-toggle">
    <span class="toc-label">Table of Contents</span>
    <svg class="toc-chevron" width="16" height="16" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><polyline points="6 9 12 15 18 9"/></svg>
  </summary>
  <nav class="toc-nav" aria-label="Table of contents">
    <ol class="toc-list">
      {headings.map((h) => (
        <li class:list={[`toc-depth-${h.depth}`]}>
          <a href={`#${h.slug}`} class="toc-link">{h.text}</a>
        </li>
      ))}
    </ol>
  </nav>
</details>

<style>
  .toc {
    border: 1px solid var(--border);
    padding: var(--space-4) var(--space-5);
    margin-bottom: var(--space-8);
    background-color: var(--bg-surface);
  }

  .toc-toggle {
    display: flex;
    align-items: center;
    justify-content: space-between;
    cursor: pointer;
    list-style: none;
    font-size: var(--text-sm);
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--accent);
  }

  .toc-toggle::-webkit-details-marker {
    display: none;
  }

  .toc-chevron {
    transform: rotate(-90deg);
    transition: transform var(--duration-fast) var(--ease-out);
  }

  .toc[open] .toc-chevron {
    transform: rotate(0deg);
  }

  .toc-nav {
    margin-top: var(--space-3);
    padding-top: var(--space-3);
    border-top: 1px solid var(--border);
  }

  .toc-list {
    list-style: none;
    padding: 0;
  }

  .toc-list li {
    padding: var(--space-1) 0;
  }

  .toc-depth-3 {
    padding-left: var(--space-4);
  }

  .toc-link {
    font-size: var(--text-sm);
    color: var(--text-secondary);
    text-decoration: none;
    transition: color var(--duration-fast) var(--ease-out);
  }

  .toc-link:hover {
    color: var(--accent);
  }
</style>