/* Article-only enhancement: existing content and native anchor links stay usable. */
.article-shell.article-with-reader {
  width: min(1100px, 90vw);
}

.article-with-reader .article-heading {
  max-width: 780px;
  min-width: 0;
  overflow-wrap: anywhere;
}

.article-with-reader .article-heading > .tags {
  flex-wrap: wrap;
  margin: 16px 0 36px;
}

.article-reading-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 260px;
  align-items: start;
  gap: clamp(32px, 5vw, 60px);
}

.article-reading-layout .article-main {
  min-width: 0;
  overflow-wrap: anywhere;
}

.article-with-reader .article-content h2,
.article-with-reader .article-content h3 {
  scroll-margin-top: var(--reader-section-offset, calc(var(--reader-header-offset, 84px) + 8px));
}

.article-reader {
  position: sticky;
  top: var(--reader-header-offset, 84px);
  grid-column: 2;
  grid-row: 1;
  min-width: 0;
  color: var(--muted);
  font-size: 0.88rem;
}

.article-reader [hidden],
.article-reader[hidden] {
  display: none !important;
}

.article-reader-panel {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface);
}

.article-reader-panel > summary {
  display: flex;
  align-items: center;
  gap: 12px;
  min-height: 52px;
  padding: 12px 16px;
  border-radius: 8px;
  color: var(--text);
  font-size: 0.84rem;
  font-weight: 700;
  list-style: none;
  cursor: pointer;
}

.article-reader-panel > summary::-webkit-details-marker {
  display: none;
}

.article-reader-panel > summary [data-reader-title] {
  flex: 1;
  min-width: 0;
  overflow-wrap: anywhere;
}

.article-reader-panel > summary::after {
  flex: 0 0 auto;
  width: 7px;
  height: 7px;
  margin: -4px 2px 0;
  border-right: 1.5px solid currentColor;
  border-bottom: 1.5px solid currentColor;
  content: "";
  transform: rotate(45deg);
}

.article-reader-panel[open] > summary {
  border-bottom: 1px solid var(--line);
  border-radius: 8px 8px 0 0;
}

.article-reader-panel[open] > summary::after {
  margin-top: 4px;
  transform: rotate(225deg);
}

.reader-percentage {
  color: var(--accent);
  font-size: 0.78rem;
  font-weight: 600;
  font-variant-numeric: tabular-nums;
}

.reader-progress {
  display: grid;
  gap: 8px;
  padding: 16px 16px 8px;
  font-size: 0.75rem;
}

.reader-progress label,
.reader-progress p {
  margin: 0;
}

.reader-progress progress {
  display: block;
  width: 100%;
  height: 4px;
  overflow: hidden;
  appearance: none;
  border: 0;
  border-radius: 999px;
  background: var(--surface-soft);
  color: var(--accent);
  accent-color: var(--accent);
}

.reader-progress progress::-webkit-progress-bar {
  border-radius: 999px;
  background: var(--surface-soft);
}

.reader-progress progress::-webkit-progress-value {
  border-radius: 999px;
  background: var(--accent);
}

.reader-progress progress::-moz-progress-bar {
  border-radius: 999px;
  background: var(--accent);
}

.reader-toc {
  max-height: max(160px, calc(100vh - var(--reader-header-offset, 84px) - 180px));
  max-height: max(160px, calc(100dvh - var(--reader-header-offset, 84px) - 180px));
  padding: 8px 10px 14px;
  overflow-y: auto;
  overscroll-behavior: contain;
  scrollbar-width: thin;
  scrollbar-color: var(--line) transparent;
}

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

.reader-empty {
  margin: 0;
  padding: 16px;
  color: var(--muted);
  font-size: 0.8rem;
}

.reader-item + .reader-item {
  margin-top: 3px;
}

.reader-item[data-depth="3"] {
  margin-left: 14px;
  font-size: 0.82rem;
}

.reader-item a {
  display: block;
  min-height: 38px;
  padding: 7px 10px;
  border-left: 2px solid transparent;
  border-radius: 0 4px 4px 0;
  line-height: 1.55;
  overflow-wrap: anywhere;
}

.reader-item a:hover {
  background: var(--surface-soft);
  color: var(--text);
}

.reader-item a[aria-current="location"] {
  border-left-color: var(--accent);
  background: var(--surface-soft);
  color: var(--accent);
  font-weight: 650;
}

.article-reader-panel > summary:focus-visible,
.reader-item a:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
}

@media (max-width: 1050px) {
  .article-shell.article-with-reader {
    width: min(780px, 90vw);
  }

  .article-reading-layout {
    display: flex;
    flex-direction: column;
    gap: 24px;
  }

  .article-reading-layout .article-main {
    width: 100%;
  }

  .article-reader {
    top: var(--reader-header-offset, 124px);
    z-index: 5;
    width: 100%;
    align-self: stretch;
    order: -1;
  }

  .article-reader-panel > summary {
    min-height: 52px;
  }

  .reader-toc {
    max-height: min(45vh, calc(100vh - var(--reader-header-offset, 124px) - 150px));
    max-height: min(45dvh, calc(100dvh - var(--reader-header-offset, 124px) - 150px));
  }

  .reader-item a {
    min-height: 44px;
  }

  .article-with-reader .article-content h2,
  .article-with-reader .article-content h3 {
    scroll-margin-top: var(--reader-section-offset, calc(var(--reader-header-offset, 124px) + 76px));
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  .article-reader *,
  .article-reader *::before,
  .article-reader *::after {
    animation: none !important;
    transition: none !important;
  }
}