.page-cases-featured {
  --rail-x: 6px;
  --rail-gap: 30px;
  --rail-node: 9px;
  padding-block: var(--space-3) var(--space-8);
}

@media (min-width: 780px) {
  .page-cases-featured {
    --rail-x: 7px;
    --rail-gap: 46px;
  }
}

/* ---------- 面包屑 ---------- */
.page-cases-featured .crumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-1);
  padding-block: var(--space-3);
  border-bottom: var(--border-thin) solid var(--color-line);
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  color: var(--color-ink-muted);
}

.page-cases-featured .crumb a {
  color: var(--color-ink-muted);
  text-decoration: none;
  border-bottom: var(--border-thin) solid transparent;
  transition: color 220ms ease-out, border-color 220ms ease-out;
}

.page-cases-featured .crumb a:hover {
  color: var(--color-ink);
  border-bottom-color: var(--color-line);
}

.page-cases-featured .crumb a:focus-visible {
  outline: 2px solid var(--color-focus);
  outline-offset: 2px;
}

.page-cases-featured .crumb-sep {
  color: var(--color-line);
}

.page-cases-featured .crumb-here {
  color: var(--color-ink);
}

/* ---------- 页头 ---------- */
.page-cases-featured .doc-head {
  display: grid;
  gap: var(--space-6);
  padding-block: var(--space-6) var(--space-8);
}

@media (min-width: 860px) {
  .page-cases-featured .doc-head {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    column-gap: var(--space-8);
    align-items: end;
    padding-block: var(--space-8);
  }
}

.page-cases-featured .doc-coords {
  margin: 0 0 var(--space-3);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.14em;
  color: var(--color-ink-muted);
}

.page-cases-featured .doc-title {
  margin: 0;
  font-family: var(--font-heading);
  font-size: var(--text-2xl);
  line-height: var(--leading-heading);
  letter-spacing: var(--tracking-heading);
  font-weight: var(--weight-heading);
  color: var(--color-ink);
}

@media (min-width: 780px) {
  .page-cases-featured .doc-title {
    font-size: var(--text-3xl);
  }
}

@media (min-width: 1000px) {
  .page-cases-featured .doc-title {
    font-size: var(--text-4xl);
  }
}

.page-cases-featured .doc-standfirst {
  margin: 0;
  max-width: 46ch;
  font-size: var(--text-base);
  line-height: 1.9;
  color: var(--color-ink-soft);
}

@media (min-width: 780px) {
  .page-cases-featured .doc-standfirst {
    font-size: var(--text-lg);
    line-height: 1.72;
  }
}

.page-cases-featured .head-meta {
  margin: var(--space-4) 0 0;
  padding-top: var(--space-3);
  border-top: var(--border-thin) solid var(--color-line);
  display: grid;
  gap: var(--space-2);
}

.page-cases-featured .head-meta > div {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: baseline;
  gap: var(--space-1) var(--space-3);
}

.page-cases-featured .head-meta dt {
  font-size: var(--text-xs);
  letter-spacing: 0.1em;
  color: var(--color-ink-muted);
}

.page-cases-featured .head-meta dd {
  margin: 0;
  font-size: var(--text-sm);
  color: var(--color-ink-soft);
  text-align: right;
}

/* ---------- 章节与轨道 ---------- */
.page-cases-featured .doc-body {
  display: grid;
  gap: 0;
}

.page-cases-featured .chapter {
  position: relative;
  padding-left: var(--rail-gap);
  padding-block: var(--space-8) 0;
}

.page-cases-featured .chapter::before {
  content: "";
  position: absolute;
  left: var(--rail-x);
  top: 0;
  bottom: 0;
  width: var(--border-thin);
  background: var(--color-line);
}

.page-cases-featured .chapter::after {
  content: "";
  position: absolute;
  left: calc(var(--rail-x) - 4px);
  top: 0;
  width: var(--rail-node);
  height: var(--rail-node);
  border: var(--border-thin) solid var(--color-ink-muted);
  background: var(--color-surface);
  border-radius: var(--radius-sm);
  transition: border-color 220ms ease-out, background-color 220ms ease-out;
}

.page-cases-featured .chapter:hover::after {
  border-color: var(--color-primary);
  background: var(--color-primary-soft);
}

.page-cases-featured .chapter--last::before {
  bottom: auto;
  height: calc(var(--space-6) + var(--space-2));
}

.page-cases-featured .chapter-kicker {
  margin: 0 0 var(--space-2);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.16em;
  color: var(--color-ink-muted);
}

.page-cases-featured .chapter-title {
  margin: 0 0 var(--space-3);
  font-family: var(--font-heading);
  font-size: var(--text-2xl);
  line-height: var(--leading-heading);
  letter-spacing: var(--tracking-heading);
  font-weight: var(--weight-heading);
  color: var(--color-ink);
}

@media (min-width: 780px) {
  .page-cases-featured .chapter-title {
    font-size: var(--text-3xl);
  }
}

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

.page-cases-featured .chapter-text p:last-child {
  margin-bottom: 0;
}

/* ---------- 边界说明 ---------- */
.page-cases-featured .scope-note {
  margin-top: var(--space-4);
  padding-block: var(--space-3);
  border-top: var(--border-thin) solid var(--color-line);
  border-bottom: var(--border-thin) solid var(--color-line);
}

.page-cases-featured .scope-note-title {
  margin: 0 0 var(--space-2);
  font-family: var(--font-heading);
  font-size: var(--text-base);
  letter-spacing: var(--tracking-heading);
  color: var(--color-ink);
}

.page-cases-featured .scope-list {
  margin: 0;
  padding-left: 1.1em;
  display: grid;
  gap: var(--space-1);
}

.page-cases-featured .scope-list li {
  max-width: var(--measure);
  font-size: var(--text-sm);
  line-height: 1.85;
  color: var(--color-ink-muted);
}

/* ---------- 归集原则 ---------- */
.page-cases-featured .principles {
  margin: var(--space-4) 0 0;
  padding: 0;
  list-style: none;
  border-top: var(--border-thin) solid var(--color-line);
}

.page-cases-featured .principle {
  display: grid;
  gap: var(--space-1);
  padding-block: var(--space-3);
  border-bottom: var(--border-thin) solid var(--color-line);
}

@media (min-width: 720px) {
  .page-cases-featured .principle {
    grid-template-columns: 76px minmax(0, 1fr);
    column-gap: var(--space-3);
    align-items: baseline;
  }
}

.page-cases-featured .principle-no {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.12em;
  color: var(--color-accent);
}

.page-cases-featured .principle-body {
  margin: 0;
  max-width: var(--measure);
  font-size: var(--text-base);
  line-height: var(--leading-body);
  color: var(--color-ink-soft);
}

/* ---------- 图片 ---------- */
.page-cases-featured .plate {
  margin: var(--space-6) 0 0;
}

.page-cases-featured .plate img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
  background: var(--color-surface-alt);
}

.page-cases-featured .plate figcaption {
  margin-top: var(--space-2);
  max-width: var(--measure);
  font-size: var(--text-xs);
  line-height: 1.8;
  letter-spacing: 0.04em;
  color: var(--color-ink-muted);
}

/* ---------- 三段推进 ---------- */
.page-cases-featured .stages {
  margin-top: var(--space-4);
}

.page-cases-featured .stage {
  border-top: var(--border-thin) solid var(--color-line);
}

.page-cases-featured .stage:last-of-type {
  border-bottom: var(--border-thin) solid var(--color-line);
}

.page-cases-featured .stage-sum {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: var(--space-2);
  padding: var(--space-3) 0;
  cursor: pointer;
  list-style: none;
}

.page-cases-featured .stage-sum::-webkit-details-marker {
  display: none;
}

.page-cases-featured .stage-no {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.12em;
  color: var(--color-ink-muted);
  transition: color 220ms ease-out;
}

.page-cases-featured .stage-name {
  font-family: var(--font-heading);
  font-size: var(--text-xl);
  line-height: var(--leading-heading);
  letter-spacing: var(--tracking-heading);
  color: var(--color-ink);
  transition: color 220ms ease-out;
}

.page-cases-featured .stage-sum::after {
  content: "展开";
  margin-left: auto;
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  color: var(--color-ink-muted);
  border-bottom: var(--border-thin) solid var(--color-line);
  transition: color 220ms ease-out, border-color 220ms ease-out;
}

.page-cases-featured .stage[open] > .stage-sum::after {
  content: "收起";
  color: var(--color-primary);
  border-bottom-color: var(--color-primary);
}

.page-cases-featured .stage[open] > .stage-sum .stage-no {
  color: var(--color-accent);
}

.page-cases-featured .stage-sum:hover .stage-name {
  color: var(--color-accent);
}

.page-cases-featured .stage-sum:focus-visible {
  outline: 2px solid var(--color-focus);
  outline-offset: 2px;
}

.page-cases-featured .stage-body {
  padding-bottom: var(--space-4);
}

.page-cases-featured .stage-fields {
  margin: 0;
  display: grid;
  gap: var(--space-3);
}

.page-cases-featured .field {
  display: grid;
  gap: var(--space-1);
}

@media (min-width: 680px) {
  .page-cases-featured .field {
    grid-template-columns: 104px minmax(0, 1fr);
    column-gap: var(--space-3);
  }
}

.page-cases-featured .field dt {
  font-size: var(--text-xs);
  letter-spacing: 0.1em;
  color: var(--color-ink-muted);
}

@media (min-width: 680px) {
  .page-cases-featured .field dt {
    padding-top: 0.55em;
  }
}

.page-cases-featured .field dd {
  margin: 0;
  max-width: var(--measure);
  font-size: var(--text-base);
  line-height: var(--leading-body);
  color: var(--color-ink-soft);
}

.page-cases-featured .chips {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-1) var(--space-2);
  margin-top: var(--space-3);
}

.page-cases-featured .chip {
  display: inline-block;
  padding: 3px var(--space-2);
  border: var(--border-thin) solid var(--color-line);
  background: var(--color-surface-alt);
  color: var(--color-ink-soft);
  border-radius: var(--radius-sm);
  font-size: var(--text-xs);
  letter-spacing: 0.04em;
}

/* ---------- 指标 ---------- */
.page-cases-featured .metrics {
  margin: var(--space-4) 0 0;
  padding: 0;
  list-style: none;
  border-top: var(--border-thin) solid var(--color-line);
}

.page-cases-featured .metric {
  display: grid;
  gap: var(--space-1);
  padding-block: var(--space-4);
  border-bottom: var(--border-thin) solid var(--color-line);
}

@media (min-width: 720px) {
  .page-cases-featured .metric {
    grid-template-columns: minmax(96px, auto) minmax(0, 1fr);
    grid-template-rows: auto auto;
    column-gap: var(--space-6);
    align-items: baseline;
  }

  .page-cases-featured .metric-num {
    grid-row: 1 / 3;
  }
}

.page-cases-featured .metric-num {
  font-family: var(--font-heading);
  font-size: var(--text-figure);
  line-height: 1;
  font-weight: var(--weight-heading);
  color: var(--color-accent);
}

.page-cases-featured .metric-label {
  font-size: var(--text-base);
  letter-spacing: 0.02em;
  line-height: 1.7;
  color: var(--color-ink);
}

.page-cases-featured .metric-note {
  font-size: var(--text-xs);
  line-height: 1.8;
  color: var(--color-ink-muted);
  transition: color 220ms ease-out;
}

.page-cases-featured .metric:hover .metric-note {
  color: var(--color-ink-soft);
}

/* ---------- 适用 / 不适用 ---------- */
.page-cases-featured .fit {
  display: grid;
  gap: var(--space-6);
  margin-top: var(--space-4);
}

@media (min-width: 780px) {
  .page-cases-featured .fit {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    column-gap: var(--space-8);
  }
}

.page-cases-featured .fit-col {
  padding-top: var(--space-3);
  border-top: var(--border-thin) solid var(--color-ink-muted);
}

.page-cases-featured .fit-col--no {
  border-top-color: var(--color-line);
}

.page-cases-featured .fit-title {
  margin: 0 0 var(--space-3);
  font-family: var(--font-heading);
  font-size: var(--text-lg);
  line-height: var(--leading-heading);
  letter-spacing: var(--tracking-heading);
  font-weight: var(--weight-heading);
  color: var(--color-ink);
}

.page-cases-featured .fit-list {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: var(--space-2);
}

.page-cases-featured .fit-list li {
  position: relative;
  padding-left: var(--space-3);
  max-width: var(--measure);
  font-size: var(--text-base);
  line-height: 1.85;
  color: var(--color-ink-soft);
}

.page-cases-featured .fit-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.74em;
  width: 5px;
  height: 5px;
  border: var(--border-thin) solid var(--color-ink-muted);
  border-radius: var(--radius-sm);
}

.page-cases-featured .fit-col--yes .fit-list li::before {
  border-color: var(--color-primary);
  background: var(--color-primary-soft);
}

/* ---------- 相邻主题 ---------- */
.page-cases-featured .next {
  margin: var(--space-4) 0 0;
  padding: 0;
  list-style: none;
  border-top: var(--border-thin) solid var(--color-line);
}

.page-cases-featured .next-item {
  border-bottom: var(--border-thin) solid var(--color-line);
}

.page-cases-featured .next-link {
  display: grid;
  gap: var(--space-1);
  margin-inline: calc(var(--space-2) * -1);
  padding: var(--space-4) var(--space-2);
  text-decoration: none;
  transition: background-color 220ms ease-out;
}

@media (min-width: 720px) {
  .page-cases-featured .next-link {
    grid-template-columns: minmax(0, 4fr) minmax(0, 6fr) auto;
    column-gap: var(--space-4);
    align-items: baseline;
  }
}

.page-cases-featured .next-link:hover {
  background: var(--color-surface-alt);
}

.page-cases-featured .next-link:focus-visible {
  outline: 2px solid var(--color-focus);
  outline-offset: -2px;
}

.page-cases-featured .next-title {
  font-family: var(--font-heading);
  font-size: var(--text-xl);
  line-height: var(--leading-heading);
  letter-spacing: var(--tracking-heading);
  color: var(--color-ink);
  transition: color 220ms ease-out;
}

.page-cases-featured .next-link:hover .next-title {
  color: var(--color-accent);
}

.page-cases-featured .next-desc {
  font-size: var(--text-sm);
  line-height: 1.85;
  color: var(--color-ink-soft);
}

.page-cases-featured .next-arrow {
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  color: var(--color-ink-muted);
  white-space: nowrap;
}

/* ---------- 返回父栏目锚点 ---------- */
.page-cases-featured .back-anchor {
  display: none;
}

@media (min-width: 1180px) {
  .page-cases-featured .back-anchor {
    display: inline-flex;
    align-items: center;
    gap: var(--space-1);
    position: fixed;
    left: var(--space-4);
    bottom: var(--space-4);
    z-index: 20;
    padding: var(--space-1) var(--space-3);
    font-size: var(--text-xs);
    letter-spacing: 0.08em;
    color: var(--color-ink-soft);
    text-decoration: none;
    background: var(--color-surface);
    border: var(--border-thin) solid var(--color-line);
    border-radius: var(--radius-sm);
    transition: color 220ms ease-out, border-color 220ms ease-out;
  }

  .page-cases-featured .back-anchor:hover {
    color: var(--color-primary);
    border-color: var(--color-primary);
  }

  .page-cases-featured .back-anchor:focus-visible {
    outline: 2px solid var(--color-focus);
    outline-offset: 2px;
  }
}