.page-insights {
  --pi-toc-width: 236px;
  --pi-chapter-gap: var(--space-6);
  display: block;
}

/* ---------- 阅读进度（渐进增强） ---------- */
.page-insights .pi-progress {
  display: none;
}

@supports (animation-timeline: scroll()) {
  .page-insights .pi-progress {
    display: block;
    position: fixed;
    inset: auto 0 0 0;
    height: 2px;
    background: var(--color-accent);
    transform: scaleX(0);
    transform-origin: 0 50%;
    z-index: 30;
    pointer-events: none;
    animation: pi-progress-grow linear both;
    animation-timeline: scroll(root block);
  }
}

@keyframes pi-progress-grow {
  from { transform: scaleX(0); }
  to { transform: scaleX(1); }
}

/* ---------- 面包屑 ---------- */
.page-insights .crumbs {
  margin-top: var(--space-4);
}

/* ---------- 首屏 ---------- */
.page-insights .pi-hero {
  padding-bottom: var(--space-8);
}

.page-insights .pi-hero__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-2);
  align-items: stretch;
}

.page-insights .pi-hero__panel {
  background: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  padding: var(--space-6) var(--space-3);
}

.page-insights .pi-hero__eyebrow {
  color: var(--color-contrast-accent);
  margin: 0 0 var(--space-3);
}

.page-insights .pi-hero__title {
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-display);
  line-height: var(--leading-heading);
  letter-spacing: var(--tracking-heading);
  color: var(--color-contrast-ink);
  margin: 0 0 var(--space-3);
}

.page-insights .pi-hero__lede {
  font-family: var(--font-body);
  font-size: var(--text-base);
  line-height: var(--leading-body);
  color: var(--color-contrast-ink);
  opacity: 0.84;
  max-width: var(--measure);
  margin: 0 0 var(--space-4);
}

.page-insights .pi-hero__stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: var(--space-2);
  margin: 0;
  padding-top: var(--space-3);
  border-top: var(--border-thin) solid var(--color-contrast-line);
}

.page-insights .pi-hero__stat dt {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.18em;
  color: var(--color-contrast-ink);
  opacity: 0.62;
  margin-bottom: var(--space-1);
}

.page-insights .pi-hero__stat dd {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: var(--text-lg);
  line-height: 1;
  color: var(--color-contrast-accent);
  margin: 0;
}

.page-insights .pi-hero__index {
  background: var(--color-surface-alt);
  padding: var(--space-6) var(--space-3);
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

.page-insights .pi-hero__index-label {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.18em;
  color: var(--color-ink-muted);
  margin: 0;
}

.page-insights .pi-hero__cells {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 0;
}

.page-insights .pi-hero__cell {
  display: block;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: var(--text-lg);
  line-height: 1;
  padding: var(--space-2) 0 var(--space-1);
  color: var(--color-ink-muted);
  text-decoration: none;
  border-top: var(--border-thin) solid var(--color-line);
  transition: color 200ms ease;
}

.page-insights .pi-hero__cell:first-child {
  color: var(--color-accent);
}

.page-insights .pi-hero__cell:hover,
.page-insights .pi-hero__cell:focus-visible {
  color: var(--color-ink);
}

.page-insights .pi-hero__cell:focus-visible {
  outline: 2px solid var(--color-focus);
  outline-offset: 2px;
}

/* ---------- 首屏横幅 ---------- */
.page-insights .pi-banner {
  margin: var(--space-4) 0 0;
  display: grid;
  gap: var(--space-2);
}

.page-insights .pi-banner img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 16 / 7;
  object-fit: cover;
  filter: saturate(0.42) contrast(1.06);
}

.page-insights .pi-banner__caption {
  padding-left: var(--space-2);
}

/* ---------- 主体布局 ---------- */
.page-insights .pi-body {
  padding-bottom: var(--space-8);
}

.page-insights .pi-layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-6);
  align-items: start;
}

/* ---------- 目录 ---------- */
.page-insights .pi-toc {
  padding-top: var(--space-4);
  border-top: var(--border-thin) solid var(--color-line);
}

.page-insights .pi-toc__label {
  color: var(--color-ink-muted);
  margin: 0 0 var(--space-3);
}

.page-insights .pi-toc__list {
  list-style: none;
  margin: 0;
  padding: 0 0 0 var(--space-3);
  border-left: var(--border-thin) solid var(--color-line);
}

.page-insights .pi-toc__part {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.12em;
  color: var(--color-primary);
  padding: var(--space-3) 0 var(--space-1);
}

.page-insights .pi-toc__part:first-child {
  padding-top: 0;
}

.page-insights .pi-toc__list a {
  position: relative;
  display: flex;
  gap: var(--space-2);
  padding: var(--space-1) 0;
  font-family: var(--font-body);
  font-size: var(--text-sm);
  line-height: 1.6;
  color: var(--color-ink-soft);
  text-decoration: none;
  transition: color 200ms ease;
}

.page-insights .pi-toc__list a::before {
  content: "";
  position: absolute;
  left: calc(-1 * var(--space-3) - 1px);
  top: 50%;
  width: 2px;
  height: 0;
  background: var(--color-accent);
  transform: translateY(-50%);
  transition: height 220ms ease;
}

.page-insights .pi-toc__list a:hover {
  color: var(--color-ink);
}

.page-insights .pi-toc__list a.is-current {
  color: var(--color-ink);
}

.page-insights .pi-toc__list a.is-current::before {
  height: 16px;
}

.page-insights .pi-toc__list a:focus-visible {
  outline: 2px solid var(--color-focus);
  outline-offset: 2px;
}

.page-insights .pi-toc__no {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  color: var(--color-primary);
  flex: 0 0 auto;
}

/* ---------- 文档 ---------- */
.page-insights .pi-doc {
  min-width: 0;
}

.page-insights .pi-part {
  padding-bottom: var(--space-6);
}

.page-insights .pi-part__head {
  padding-bottom: var(--space-3);
  margin-bottom: var(--space-6);
  border-bottom: var(--border-thin) solid var(--color-line);
}

.page-insights .pi-part__no {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.18em;
  color: var(--color-primary);
  margin: 0 0 var(--space-2);
}

.page-insights .pi-part__title {
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: calc(var(--text-2xl) * 0.72);
  line-height: var(--leading-heading);
  letter-spacing: var(--tracking-heading);
  color: var(--color-ink);
  margin: 0 0 var(--space-3);
}

.page-insights .pi-part__intro {
  font-family: var(--font-body);
  font-size: var(--text-base);
  line-height: var(--leading-body);
  color: var(--color-ink-soft);
  max-width: var(--measure);
  margin: 0;
}

/* ---------- 章节 ---------- */
.page-insights .pi-chapter {
  padding-top: var(--space-4);
}

.page-insights .pi-chapter + .pi-chapter {
  margin-top: var(--space-6);
  border-top: var(--border-thin) solid var(--color-line);
}

.page-insights .pi-chapter__head {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: var(--space-1) var(--space-3);
  align-items: baseline;
  margin-bottom: var(--space-3);
}

.page-insights .pi-chapter__no {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: var(--text-lg);
  line-height: 1;
  color: var(--color-primary);
}

.page-insights .pi-chapter__title {
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: calc(var(--text-xl) * 0.76);
  line-height: var(--leading-heading);
  letter-spacing: var(--tracking-heading);
  color: var(--color-ink);
  margin: 0;
}

.page-insights .pi-chapter__lede {
  font-family: var(--font-body);
  font-size: var(--text-lg);
  line-height: 1.6;
  color: var(--color-ink);
  max-width: var(--measure);
  margin: 0 0 var(--space-3);
}

.page-insights .pi-chapter__body p {
  font-family: var(--font-body);
  font-size: var(--text-base);
  line-height: var(--leading-body);
  color: var(--color-ink-soft);
  max-width: var(--measure);
  margin: 0 0 var(--space-3);
}

.page-insights .pi-chapter__body p:last-child {
  margin-bottom: 0;
}

.page-insights .pi-chapter__body a {
  color: var(--color-primary);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.page-insights .pi-chapter__body a:hover {
  color: var(--color-accent);
}

.page-insights .pi-chapter__body a:focus-visible {
  outline: 2px solid var(--color-focus);
  outline-offset: 2px;
}

/* ---------- 要点框 ---------- */
.page-insights .pi-note {
  margin: var(--space-4) 0 0;
  background: var(--color-surface-alt);
  border-left: 2px solid var(--color-primary);
  padding: var(--space-2) var(--space-3);
}

.page-insights .pi-note > summary {
  cursor: pointer;
  list-style: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: var(--space-2);
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  letter-spacing: 0.08em;
  color: var(--color-primary);
}

.page-insights .pi-note > summary::-webkit-details-marker {
  display: none;
}

.page-insights .pi-note > summary::after {
  content: "－";
  font-size: var(--text-sm);
  color: var(--color-ink-muted);
}

.page-insights .pi-note:not([open]) > summary::after {
  content: "＋";
}

.page-insights .pi-note > summary:focus-visible {
  outline: 2px solid var(--color-focus);
  outline-offset: 2px;
}

.page-insights .pi-note ul {
  list-style: none;
  margin: var(--space-2) 0 0;
  padding: 0;
}

.page-insights .pi-note li {
  position: relative;
  padding-left: var(--space-2);
  margin-bottom: var(--space-1);
  font-family: var(--font-body);
  font-size: var(--text-sm);
  line-height: 1.72;
  color: var(--color-ink);
}

.page-insights .pi-note li:last-child {
  margin-bottom: 0;
}

.page-insights .pi-note li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.85em;
  width: 8px;
  height: 1px;
  background: var(--color-primary);
}

/* ---------- 图 ---------- */
.page-insights .pi-figure {
  margin: var(--space-6) 0 0;
  display: grid;
  gap: var(--space-2);
  max-width: 640px;
}

.page-insights .pi-figure--wide {
  max-width: 760px;
}

.page-insights .pi-figure img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
  filter: saturate(0.4) contrast(1.05);
}

.page-insights .pi-figure .plate {
  padding-left: var(--space-2);
}

/* ---------- 小结 ---------- */
.page-insights .pi-summary {
  margin-top: var(--space-6);
  padding-top: var(--space-3);
  border-top: var(--border-thin) solid var(--color-line);
}

.page-insights .pi-summary__label {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.18em;
  color: var(--color-ink-muted);
  margin: 0 0 var(--space-2);
}

.page-insights .pi-summary__text {
  font-family: var(--font-body);
  font-size: var(--text-base);
  line-height: var(--leading-body);
  color: var(--color-ink);
  max-width: var(--measure);
  margin: 0;
}

/* ---------- 留黑分隔 ---------- */
.page-insights .pi-interlude {
  background: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  padding: var(--space-4) var(--space-3);
  margin: var(--space-6) 0;
}

.page-insights .pi-interlude__text {
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-lg);
  line-height: 1.5;
  letter-spacing: var(--tracking-heading);
  color: var(--color-contrast-ink);
  max-width: var(--measure);
  margin: 0 0 var(--space-3);
}

.page-insights .pi-interlude__facts {
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  letter-spacing: 0.06em;
  color: var(--color-contrast-ink);
  opacity: 0.72;
  margin: 0;
  padding-top: var(--space-2);
  border-top: var(--border-thin) solid var(--color-contrast-line);
}

.page-insights .pi-interlude__facts span {
  color: var(--color-contrast-accent);
}

/* ---------- 延伸阅读 ---------- */
.page-insights .pi-next {
  margin-top: var(--space-8);
  padding-top: var(--space-4);
  border-top: var(--border-thin) solid var(--color-line);
}

.page-insights .pi-next__title {
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: calc(var(--text-xl) * 0.84);
  line-height: var(--leading-heading);
  letter-spacing: var(--tracking-heading);
  color: var(--color-ink);
  margin: 0 0 var(--space-4);
}

.page-insights .pi-next__list {
  list-style: none;
  margin: 0;
  padding: 0;
  border-top: var(--border-thin) solid var(--color-line);
}

.page-insights .pi-next__list li {
  border-bottom: var(--border-thin) solid var(--color-line);
}

.page-insights .pi-next__link {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: var(--space-1) var(--space-3);
  padding: var(--space-3) 0;
  text-decoration: none;
  transition: background-color 200ms ease;
}

.page-insights .pi-next__link:hover {
  background: var(--color-primary-soft);
}

.page-insights .pi-next__link:focus-visible {
  outline: 2px solid var(--color-focus);
  outline-offset: -2px;
}

.page-insights .pi-next__no {
  grid-row: 1 / span 2;
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  color: var(--color-primary);
  line-height: 1.8;
}

.page-insights .pi-next__name {
  font-family: var(--font-heading);
  font-size: var(--text-base);
  line-height: 1.6;
  color: var(--color-ink);
}

.page-insights .pi-next__desc {
  font-family: var(--font-body);
  font-size: var(--text-sm);
  line-height: 1.7;
  color: var(--color-ink-soft);
}

/* ---------- 移动端优先之上的排版 ---------- */
@media (min-width: 720px) {
  .page-insights .pi-hero__panel,
  .page-insights .pi-hero__index {
    padding: var(--space-8) var(--space-6);
  }

  .page-insights .pi-hero__stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-insights .pi-part__title {
    font-size: var(--text-2xl);
  }

  .page-insights .pi-chapter__title {
    font-size: var(--text-xl);
  }

  .page-insights .pi-note {
    padding: var(--space-3) var(--space-4);
  }

  .page-insights .pi-interlude {
    padding: var(--space-6) var(--space-4);
    margin: var(--space-8) 0;
  }

  .page-insights .pi-next__title {
    font-size: var(--text-xl);
  }
}

@media (min-width: 960px) {
  .page-insights .pi-hero__grid {
    grid-template-columns: minmax(0, 1.12fr) minmax(0, 0.88fr);
    gap: var(--space-3);
  }

  .page-insights .pi-layout {
    grid-template-columns: var(--pi-toc-width) minmax(0, 1fr);
    gap: var(--space-8);
  }

  .page-insights .pi-toc {
    position: sticky;
    top: var(--space-8);
    align-self: start;
    max-height: calc(100vh - var(--space-8) * 2);
    overflow-y: auto;
    padding-top: var(--space-2);
  }

  .page-insights .pi-part {
    padding-bottom: var(--section-y);
  }

  .page-insights .pi-part__head {
    margin-bottom: var(--space-8);
  }

  .page-insights .pi-chapter {
    padding-top: var(--space-6);
  }

  .page-insights .pi-chapter + .pi-chapter {
    margin-top: var(--space-8);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-insights .pi-toc__list a::before,
  .page-insights .pi-hero__cell,
  .page-insights .pi-next__link {
    transition: none;
  }

  .page-insights [data-reveal] {
    opacity: 1;
    transform: none;
  }
}