@layer layout {
  .sidebar {
    position: fixed;
    top: 0;
    left: 0;
    bottom: 0;
    width: 220px;
    background: var(--color-canvas);
    border-right: 1px solid var(--color-border);
    display: flex;
    flex-direction: column;
    z-index: 100;
    overflow-y: auto;
    translate: -100%;
    transition: translate 200ms ease;
  }

  .sidebar--open {
    translate: 0;
  }

  .sidebar-backdrop {
    display: none;
    position: fixed;
    inset: 0;
    background: oklch(0% 0 0 / 0.4);
    z-index: 99;
  }

  .sidebar--open ~ .sidebar-backdrop,
  .sidebar-backdrop--visible {
    display: block;
  }

  .sidebar-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--block-space) var(--block-space-double);
    font-size: var(--text-large);
    font-weight: 700;
  }

  .feedback-icon-button {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    background: var(--color-canvas);
    border: 1px solid var(--color-border);
    padding: 0.35em;
    cursor: pointer;
    color: var(--color-ink-muted);
    border-radius: 6px;
    transition: color 150ms ease, border-color 150ms ease;
  }

  .feedback-icon-button:hover {
    color: var(--color-primary);
    border-color: color-mix(in oklch, var(--color-primary) 30%, var(--color-border));
  }

  .feedback-icon-button--end {
    margin-left: auto;
  }

  .sidebar-nav {
    list-style: none;
    margin: 0;
    padding: 0;
    flex: 1;
  }

  .sidebar-divider {
    height: 1px;
    background: var(--color-border);
    margin: var(--block-space-half) var(--block-space-double);
  }

  .sidebar-nav-item {
    padding: 0;
  }

  .sidebar-nav-link {
    display: block;
    width: 100%;
    padding: 0.4rem var(--block-space-double);
    color: var(--color-ink);
    text-decoration: none;
    font: inherit;
    font-size: var(--text-normal);
    text-align: left;
    background: none;
    border: none;
    cursor: pointer;
    transition: background-color 100ms ease, color 100ms ease;
  }

  .sidebar-nav-link:hover {
    background: var(--color-primary-soft);
    color: var(--color-primary);
  }

  .sidebar-nav-link.active {
    color: var(--color-primary);
    font-weight: 600;
  }

  .sidebar-nav-sublink {
    display: block;
    padding: 0.25rem var(--block-space-double) 0.25rem calc(var(--block-space-double) + 1.25rem);
    color: var(--color-ink-muted);
    text-decoration: none;
    font-size: var(--text-small);
    transition: background-color 100ms ease, color 100ms ease;
    position: relative;
  }

  .sidebar-nav-sublink:hover {
    background: var(--color-primary-soft);
    color: var(--color-primary);
  }

  .sidebar-nav-sublink.active {
    color: var(--color-primary);
    font-weight: 600;
  }

  .sidebar-nav-sublink.active::before {
    content: "›";
    position: absolute;
    left: calc(var(--block-space-double) + 0.25rem);
    font-weight: 700;
  }

  .sidebar-footer {
    padding: var(--block-space-half) var(--block-space-double);
    border-top: 1px solid var(--color-border);
    font-size: var(--text-small);
    color: var(--color-ink-muted);
  }

  .sidebar-footer-button {
    display: block;
    width: 100%;
    padding: 0.4rem 0;
    text-align: left;
    background: none;
    border: none;
    color: var(--color-ink-muted);
    font: inherit;
    font-size: var(--text-small);
    cursor: pointer;
  }

  .sidebar-footer-button:hover {
    color: var(--color-primary);
  }

  /* Desktop: sidebar always visible */
  @media (min-width: 1280px) {
    .sidebar {
      translate: 0;
    }

    .sidebar-backdrop {
      display: none !important;
    }

    .header--mobile {
      display: none;
    }

    .page {
      margin-left: 220px;
    }
  }

  /* Mobile header */
  .header--mobile {
    display: flex;
    align-items: center;
    height: calc(var(--block-space) * 3.86);
    padding-inline: var(--block-space);
    background: var(--color-canvas);
    border-bottom: 1px solid var(--color-border);
    gap: var(--block-space);
  }

  .header--mobile .app-logo {
    font-size: var(--text-large);
    font-weight: 700;
  }

  .sidebar-toggle {
    display: flex;
    align-items: center;
    justify-content: center;
    background: none;
    border: none;
    padding: 0.5em;
    cursor: pointer;
    color: var(--color-ink);
  }

  .sidebar-toggle svg {
    width: 1.25em;
    height: 1.25em;
  }

  @media (min-width: 1280px) {
    .header--mobile {
      display: none;
    }
  }
}