.page-about {
  --about-rail-width: 104px;
  --about-line: rgba(31, 111, 122, 0.38);
  --about-body-dim: rgba(232, 246, 250, 0.84);
}

.page-about .breadcrumbs {
  padding-top: 28px;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  padding: 32px 0 56px;
}

.page-about .about-hero-grid {
  display: grid;
  gap: 36px;
}

.page-about .about-hero-main .section-kicker {
  margin: 0 0 14px;
}

.page-about .display-title {
  margin: 0 0 22px;
  font-size: clamp(32px, 8.4vw, 66px);
  line-height: 1.1;
  letter-spacing: 0.015em;
}

.page-about .lede {
  max-width: 60ch;
  color: var(--about-body-dim);
  line-height: 1.8;
}

.page-about .about-hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 30px;
}

.page-about .about-stats {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 20px 22px;
}

.page-about .about-stat {
  border-top: 1px solid var(--edge);
  padding-top: 14px;
}

.page-about .about-stat-num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(26px, 6vw, 34px);
  font-weight: 600;
  line-height: 1.05;
  color: var(--cyan);
  font-variant-numeric: tabular-nums;
  letter-spacing: 0.01em;
}

.page-about .about-stat-label {
  display: block;
  margin-top: 8px;
  font-size: 13px;
  line-height: 1.6;
  color: var(--muted);
}

/* ---------- 页内目录 ---------- */
.page-about .about-toc {
  display: flex;
  gap: 10px;
  overflow-x: auto;
  padding: 4px 0 14px;
  scrollbar-width: none;
}

.page-about .about-toc::-webkit-scrollbar {
  display: none;
}

.page-about .about-toc-link {
  flex: none;
  font-size: 13px;
  padding: 7px 15px;
  border-radius: var(--radius-pill);
  background: var(--panel);
  color: var(--muted);
  text-decoration: none;
  transition: color 0.24s ease, background 0.24s ease;
}

.page-about .about-toc-link:hover,
.page-about .about-toc-link:focus-visible {
  color: var(--text);
  background: rgba(167, 107, 255, 0.2);
}

/* ---------- 通用内容段 ---------- */
.page-about .about-block {
  position: relative;
  padding: 56px 0;
  scroll-margin-top: calc(var(--header-h) + 20px);
}

.page-about .about-block--tint {
  background: var(--ink-1);
}

.page-about .about-grid {
  display: grid;
  gap: 22px;
}

.page-about .about-rail {
  display: flex;
  align-items: center;
  gap: 14px;
}

.page-about .about-rail-index {
  font-family: var(--font-mono);
  font-size: 26px;
  line-height: 1;
  color: var(--cyan);
  letter-spacing: 0.02em;
}

.page-about .about-rail-note {
  font-size: 12px;
  letter-spacing: 0.22em;
  color: var(--muted);
}

.page-about .about-body {
  min-width: 0;
}

.page-about .about-body .section-title {
  margin: 0 0 16px;
  font-size: clamp(23px, 5vw, 34px);
  line-height: 1.32;
  letter-spacing: 0.01em;
}

.page-about .about-lead {
  margin: 0 0 18px;
  font-size: clamp(17px, 3.6vw, 20px);
  font-weight: 700;
  line-height: 1.65;
  color: var(--text);
}

.page-about .about-text {
  margin: 0 0 16px;
  color: var(--about-body-dim);
  line-height: 1.8;
}

.page-about .about-text:last-child {
  margin-bottom: 0;
}

.page-about .about-tags {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 22px 0 0;
  padding: 0;
}

.page-about .about-tag {
  font-size: 13px;
  padding: 6px 14px;
  border-radius: var(--radius-pill);
  background: var(--panel);
  color: var(--muted);
  transition: background 0.24s ease, color 0.24s ease;
}

.page-about .about-tag:hover {
  background: rgba(167, 107, 255, 0.18);
  color: var(--text);
}

/* ---------- 沿革时间线 ---------- */
.page-about .about-timeline-block {
  overflow: hidden;
}

.page-about .about-timeline-bg {
  position: absolute;
  inset: 0;
  margin: 0;
  opacity: 0.16;
  pointer-events: none;
}

.page-about .about-timeline-bg img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.page-about .about-timeline-block > .wrap {
  position: relative;
  z-index: 1;
}

.page-about .timeline {
  list-style: none;
  margin: 26px 0 0;
  padding: 0 0 0 26px;
  position: relative;
}

.page-about .timeline::before {
  content: "";
  position: absolute;
  left: 7px;
  top: 10px;
  bottom: 10px;
  width: 2px;
  border-radius: 2px;
  background: linear-gradient(180deg, var(--edge) 0%, var(--edge) 35%, var(--cyan) 100%);
}

.page-about .timeline-item {
  position: relative;
  padding-bottom: 30px;
  border-radius: var(--radius-md);
  transition: background 0.26s ease;
}

.page-about .timeline-item:last-child {
  padding-bottom: 0;
}

.page-about .timeline-item:hover {
  background: rgba(21, 27, 34, 0.72);
}

.page-about .timeline-dot {
  position: absolute;
  left: -26px;
  top: 6px;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--ink-0);
  border: 2px solid var(--muted);
  transition: border-color 0.26s ease, box-shadow 0.26s ease, background 0.26s ease;
}

.page-about .timeline-item--now .timeline-dot {
  border-color: var(--cyan);
  background: var(--cyan);
  box-shadow: 0 0 0 5px rgba(0, 229, 255, 0.14);
}

.page-about .timeline-item:hover .timeline-dot {
  border-color: var(--cyan);
  box-shadow: 0 0 0 5px rgba(0, 229, 255, 0.12);
}

.page-about .timeline-stage {
  display: block;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.2em;
  color: var(--amber);
  margin-bottom: 8px;
}

.page-about .timeline-title {
  margin: 0 0 8px;
  font-size: 18px;
  font-weight: 700;
  line-height: 1.5;
  color: var(--text);
}

.page-about .timeline-text {
  margin: 0;
  color: var(--muted);
  line-height: 1.8;
}

/* ---------- 图文分栏 ---------- */
.page-about .about-split {
  display: grid;
  gap: 30px;
  margin-top: 8px;
}

.page-about .about-split-media {
  margin: 0;
  overflow: hidden;
  border-radius: var(--radius-lg);
  background: var(--panel);
}

.page-about .about-split-media img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
}

/* ---------- 四级索引 ---------- */
.page-about .level-stack {
  display: grid;
  gap: 10px;
  margin-top: 24px;
}

.page-about .level-row {
  border-radius: var(--radius-md);
  background: var(--panel);
  overflow: hidden;
  min-width: 0;
}

.page-about .level-row--2 {
  margin-left: 8px;
}

.page-about .level-row--3 {
  margin-left: 16px;
}

.page-about .level-row--4 {
  margin-left: 24px;
}

.page-about .level-summary {
  list-style: none;
  cursor: pointer;
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 10px;
  padding: 15px 18px;
  transition: background 0.24s ease;
}

.page-about .level-summary::-webkit-details-marker {
  display: none;
}

.page-about .level-summary:hover {
  background: rgba(167, 107, 255, 0.12);
}

.page-about .level-num {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--edge);
}

.page-about .level-row[open] .level-num {
  color: var(--cyan);
}

.page-about .level-pill {
  font-size: 13px;
  font-weight: 700;
  padding: 4px 13px;
  border-radius: var(--radius-pill);
  background: rgba(0, 229, 255, 0.1);
  color: var(--cyan);
}

.page-about .level-text {
  font-size: 13px;
  color: var(--muted);
}

.page-about .level-samples {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  padding: 0 18px 18px;
}

.page-about .level-sample {
  font-family: var(--font-mono);
  font-size: 12px;
  padding: 4px 11px;
  border-radius: var(--radius-pill);
  background: rgba(0, 229, 255, 0.06);
  color: var(--muted);
  border: 1px solid rgba(0, 229, 255, 0.18);
}

/* ---------- 编辑与校对 ---------- */
.page-about .editor-roles {
  display: grid;
  gap: 16px;
  margin-top: 24px;
}

.page-about .editor-role {
  background: var(--panel);
  border-radius: var(--radius-lg);
  padding: 22px 22px 24px;
  border: 1px solid transparent;
  transition: border-color 0.26s ease;
}

.page-about .editor-role:hover {
  border-color: var(--edge);
}

.page-about .editor-role-count {
  display: block;
  font-family: var(--font-mono);
  font-size: 38px;
  font-weight: 600;
  line-height: 1;
  color: var(--cyan);
  font-variant-numeric: tabular-nums;
}

.page-about .editor-role-name {
  margin: 12px 0 8px;
  font-size: 17px;
  font-weight: 700;
  color: var(--text);
}

.page-about .editor-role-desc {
  margin: 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--muted);
}

/* ---------- 巡检清单 ---------- */
.page-about .audit-list {
  list-style: none;
  margin: 24px 0 0;
  padding: 0;
  display: grid;
  gap: 14px;
}

.page-about .audit-item {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 16px;
  padding: 20px 20px;
  border-radius: var(--radius-lg);
  background: var(--panel);
  border-left: 2px solid var(--edge);
  transition: border-left-color 0.26s ease, background 0.26s ease;
}

.page-about .audit-item:hover {
  border-left-color: var(--cyan);
  background: #182028;
}

.page-about .audit-num {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--amber);
  letter-spacing: 0.08em;
  padding-top: 3px;
}

.page-about .audit-title {
  margin: 0 0 6px;
  font-size: 16px;
  font-weight: 700;
  color: var(--text);
}

.page-about .audit-text {
  margin: 0;
  font-size: 14px;
  line-height: 1.78;
  color: var(--muted);
}

/* ---------- 供稿生态 ---------- */
.page-about .filter-bar {
  margin-top: 24px;
  flex-wrap: wrap;
}

.page-about .contrib-list {
  list-style: none;
  margin: 24px 0 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--about-line);
  border-radius: var(--radius-lg);
  overflow: hidden;
}

.page-about .contrib-item {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 6px 16px;
  align-items: start;
  padding: 18px 20px;
  background: var(--ink-0);
  transition: background 0.24s ease;
}

.page-about .contrib-item[hidden] {
  display: none;
}

.page-about .contrib-item:hover {
  background: var(--panel);
}

.page-about .contrib-index {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--edge);
  padding-top: 2px;
}

.page-about .contrib-item:hover .contrib-index {
  color: var(--cyan);
}

.page-about .contrib-body {
  min-width: 0;
}

.page-about .contrib-title {
  margin: 0 0 6px;
  font-size: 16px;
  font-weight: 700;
  color: var(--text);
}

.page-about .contrib-desc {
  margin: 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--muted);
}

.page-about .contrib-tag {
  grid-column: 2;
  justify-self: start;
  font-size: 12px;
  padding: 3px 11px;
  border-radius: var(--radius-pill);
  background: rgba(255, 177, 61, 0.12);
  color: var(--amber);
}

.page-about .filter-empty {
  margin: 18px 0 0;
  font-size: 14px;
  color: var(--muted);
}

/* ---------- 结尾引导 ---------- */
.page-about .about-cta {
  padding: 64px 0 88px;
}

.page-about .about-cta-inner {
  border-radius: var(--radius-xl);
  border: 1px solid var(--edge);
  background: linear-gradient(135deg, rgba(0, 229, 255, 0.1) 0%, rgba(167, 107, 255, 0.08) 55%, rgba(7, 9, 12, 0) 100%);
  padding: clamp(26px, 5vw, 54px);
}

.page-about .about-cta-inner .section-title {
  margin: 0 0 16px;
  font-size: clamp(22px, 5vw, 32px);
  line-height: 1.35;
}

.page-about .about-cta-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 28px;
}

/* ---------- 桌面栅格 ---------- */
@media (min-width: 900px) {
  .page-about .about-hero {
    padding: 48px 0 76px;
  }

  .page-about .about-hero-grid {
    grid-template-columns: minmax(0, 7.2fr) minmax(0, 3fr);
    gap: 56px;
    align-items: start;
  }

  .page-about .about-hero-aside {
    padding-top: 42px;
  }

  .page-about .about-block {
    padding: 96px 0;
  }

  .page-about .about-grid {
    grid-template-columns: var(--about-rail-width) minmax(0, 1fr);
    gap: 52px;
  }

  .page-about .about-rail {
    position: sticky;
    top: calc(var(--header-h) + 28px);
    align-self: start;
    flex-direction: column;
    align-items: flex-start;
    gap: 16px;
  }

  .page-about .about-rail-note {
    writing-mode: vertical-rl;
    text-orientation: upright;
    letter-spacing: 0.3em;
    font-size: 12px;
  }

  .page-about .about-split {
    grid-template-columns: minmax(0, 1.12fr) minmax(0, 0.88fr);
    gap: 52px;
    align-items: start;
  }

  .page-about .about-split--media-left {
    grid-template-columns: minmax(0, 0.88fr) minmax(0, 1.12fr);
  }

  .page-about .about-split--media-left .about-split-media {
    order: -1;
  }

  .page-about .editor-roles {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 20px;
  }

  .page-about .audit-list {
    gap: 16px;
  }

  .page-about .contrib-item {
    grid-template-columns: auto minmax(0, 1fr) auto;
    align-items: center;
    padding: 22px 26px;
  }

  .page-about .contrib-tag {
    grid-column: auto;
    justify-self: end;
  }

  .page-about .about-cta {
    padding: 96px 0 120px;
  }
}

@media (min-width: 1240px) {
  .page-about .about-hero-grid {
    grid-template-columns: minmax(0, 7.6fr) minmax(0, 2.6fr);
  }

  .page-about .about-grid {
    grid-template-columns: var(--about-rail-width) minmax(0, 1fr);
    gap: 64px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-toc-link,
  .page-about .about-tag,
  .page-about .timeline-item,
  .page-about .timeline-dot,
  .page-about .level-summary,
  .page-about .editor-role,
  .page-about .audit-item,
  .page-about .contrib-item {
    transition: none;
  }
}