.page-about {
  --about-rail-w: 208px;
  --about-hair: 1px solid var(--line-leaf);
  padding-block: clamp(18px, 3vw, 36px) clamp(56px, 8vw, 112px);
}

/* ---------- 刊头区 ---------- */
.page-about .about-mast {
  position: relative;
  margin-top: clamp(18px, 3vw, 34px);
  padding-top: clamp(20px, 3vw, 38px);
  border-top: var(--about-hair);
}

.page-about .about-mast::before {
  content: "";
  position: absolute;
  top: calc(-1 * 1px);
  left: 0;
  width: clamp(56px, 12vw, 148px);
  height: 3px;
  background: linear-gradient(90deg, var(--accent-cyan), var(--accent-gold));
}

.page-about .about-mast__title {
  margin: 12px 0 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-stretch: condensed;
  font-size: clamp(34px, 6.6vw, 68px);
  line-height: 1.02;
  letter-spacing: -0.022em;
  max-width: 17ch;
}

.page-about .about-mast__lede {
  max-width: 38em;
  margin: clamp(16px, 2vw, 22px) 0 0;
  font-size: clamp(15px, 1.35vw, 17px);
  line-height: 1.78;
  color: var(--text-muted);
}

.page-about .about-band {
  margin-top: clamp(24px, 3.4vw, 42px);
}

/* ---------- 档案柜骨架：粘性索引 + 分栏叙事 ---------- */
.page-about .about-body {
  display: grid;
  gap: clamp(22px, 3vw, 46px);
  margin-top: clamp(30px, 4.6vw, 62px);
}

.page-about .about-rail__list {
  display: flex;
  gap: 8px;
  margin: 0;
  padding: 0 0 6px;
  list-style: none;
  overflow-x: auto;
  scrollbar-width: none;
  -webkit-overflow-scrolling: touch;
}

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

.page-about .about-rail__link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 12px;
  white-space: nowrap;
  font-size: 13px;
  color: var(--text-muted);
  text-decoration: none;
  background: var(--bg-field);
  border: var(--about-hair);
  border-radius: var(--radius);
  transition: color var(--dur-1) var(--ease),
              border-color var(--dur-1) var(--ease),
              background-color var(--dur-1) var(--ease);
}

.page-about .about-rail__link:hover,
.page-about .about-rail__link:focus-visible {
  color: var(--accent-cyan-soft);
  border-color: var(--accent-cyan);
  background: var(--glass-panel);
}

.page-about .about-rail__num {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.06em;
  color: var(--accent-cyan);
}

/* ---------- 章节 ---------- */
.page-about .about-chapter {
  position: relative;
  padding-block: clamp(26px, 3.6vw, 48px);
  border-top: var(--about-hair);
  scroll-margin-top: 96px;
}

.page-about .about-chapter:first-child {
  border-top: 0;
  padding-top: 0;
}

.page-about .about-chapter:target::before {
  content: "";
  position: absolute;
  left: -14px;
  top: clamp(26px, 3.6vw, 48px);
  bottom: clamp(26px, 3.6vw, 48px);
  width: 3px;
  background: var(--accent-cyan);
}

.page-about .about-chapter .section-head__title {
  margin-top: 8px;
  font-size: clamp(22px, 3vw, 31px);
  line-height: 1.16;
  letter-spacing: -0.012em;
}

.page-about .about-chapter .section-head__note {
  max-width: 36em;
}

.page-about .about-chapter .prose p + p {
  margin-top: 1.05em;
}

.page-about .about-chapter .prose strong {
  color: var(--accent-cyan-soft);
  font-weight: 600;
}

.page-about .about-chapter .prose a {
  color: var(--accent-cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(43, 240, 208, 0.42);
  transition: color var(--dur-1) var(--ease), border-color var(--dur-1) var(--ease);
}

.page-about .about-chapter .prose a:hover,
.page-about .about-chapter .prose a:focus-visible {
  color: var(--accent-cyan-soft);
  border-bottom-color: var(--accent-cyan-soft);
}

/* ---------- 入选标准 ---------- */
.page-about .criteria {
  margin: 18px 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 10px;
}

.page-about .criteria li {
  display: grid;
  grid-template-columns: 30px minmax(0, 1fr);
  gap: 12px;
  align-items: start;
  padding: 12px 14px;
  background: var(--bg-field);
  border-left: 2px solid var(--line-leaf);
}

.page-about .criteria__idx {
  font-family: var(--font-mono);
  font-size: 12px;
  line-height: 1.9;
  color: var(--accent-gold);
}

/* ---------- 可展开口径条目 ---------- */
.page-about .metric-list {
  display: grid;
  gap: 10px;
  margin-top: clamp(20px, 2.6vw, 30px);
}

.page-about .note-toggle {
  background: var(--glass-panel);
  border: var(--about-hair);
  border-radius: var(--radius);
  transition: border-color var(--dur-1) var(--ease),
              background-color var(--dur-1) var(--ease);
}

.page-about .note-toggle:hover {
  border-color: var(--accent-cyan);
}

.page-about .note-toggle[open] {
  background: var(--bg-field);
  border-color: var(--accent-cyan);
}

.page-about .note-toggle__sum {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 14px;
  padding: 13px 16px;
  list-style: none;
  cursor: pointer;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 15px;
  letter-spacing: 0.01em;
  color: var(--text-primary);
}

.page-about .note-toggle__sum::-webkit-details-marker {
  display: none;
}

.page-about .note-toggle__sum::after {
  content: "+";
  flex: none;
  font-family: var(--font-mono);
  font-size: 17px;
  line-height: 1;
  color: var(--accent-cyan);
}

.page-about .note-toggle[open] .note-toggle__sum::after {
  content: "\2212";
}

.page-about .note-toggle__meta {
  margin-left: auto;
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--text-muted);
}

.page-about .note-toggle__body {
  padding: 0 16px 16px;
  font-size: 14px;
  line-height: 1.72;
  color: var(--text-muted);
}

.page-about .formula {
  display: block;
  margin-top: 10px;
  padding: 10px 13px;
  font-family: var(--font-mono);
  font-size: 12.5px;
  line-height: 1.6;
  color: var(--accent-cyan-soft);
  background: rgba(43, 240, 208, 0.07);
  border-left: 2px solid var(--accent-cyan);
  overflow-wrap: anywhere;
}

/* ---------- 图 ---------- */
.page-about .figure-frame {
  margin: clamp(22px, 3vw, 34px) 0 0;
}

/* ---------- 时间轴 ---------- */
.page-about .about-chapter .filter-bar {
  margin-top: clamp(20px, 2.6vw, 30px);
}

.page-about .timeline {
  position: relative;
  margin: clamp(18px, 2.4vw, 26px) 0 0;
  padding: 0 0 0 26px;
  list-style: none;
}

.page-about .timeline::before {
  content: "";
  position: absolute;
  left: 7px;
  top: 10px;
  bottom: 10px;
  width: 1px;
  background: linear-gradient(180deg, var(--accent-cyan), var(--line-leaf) 62%, transparent);
}

.page-about .timeline__item {
  position: relative;
  padding: 0 0 22px;
}

.page-about .timeline__item + .timeline__item {
  padding-top: 22px;
  border-top: 1px dashed var(--line-leaf);
}

.page-about .timeline__item::before {
  content: "";
  position: absolute;
  left: -25px;
  top: 4px;
  width: 13px;
  height: 13px;
  border-radius: 50%;
  background: var(--bg-abyss);
  border: 2px solid var(--accent-cyan);
}

.page-about .timeline__item + .timeline__item::before {
  top: 26px;
}

.page-about .timeline__stamp {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--accent-gold);
}

.page-about .timeline__title {
  margin: 6px 0 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(17px, 2vw, 21px);
  line-height: 1.28;
  color: var(--text-primary);
}

.page-about .timeline__text {
  margin: 8px 0 0;
  max-width: 36em;
  font-size: clamp(14px, 1.2vw, 15.5px);
  line-height: 1.78;
  color: var(--text-muted);
}

/* ---------- 团队 ---------- */
.page-about .team-split {
  display: grid;
  gap: clamp(22px, 3vw, 40px);
  margin-top: clamp(22px, 3vw, 34px);
}

.page-about .team-donut {
  width: 100%;
  max-width: 250px;
  height: auto;
  justify-self: center;
}

.page-about .team-legend {
  display: grid;
  gap: 0;
  margin: 0;
  padding: 0;
  list-style: none;
  align-self: center;
}

.page-about .team-legend__item {
  display: grid;
  grid-template-columns: 10px minmax(0, 1fr) auto;
  gap: 14px;
  align-items: center;
  padding: 12px 0;
  border-bottom: var(--about-hair);
}

.page-about .team-legend__item:first-child {
  border-top: var(--about-hair);
}

.page-about .team-legend__swatch {
  width: 10px;
  height: 10px;
  display: block;
  border-radius: 1px;
}

.page-about .team-legend__name {
  font-size: 15px;
  color: var(--text-primary);
}

.page-about .team-legend__count {
  font-size: 14px;
  color: var(--accent-cyan-soft);
}

/* ---------- 尾随入口 ---------- */
.page-about .about-next {
  margin-top: clamp(30px, 4vw, 52px);
  padding-top: clamp(20px, 2.6vw, 30px);
  border-top: solid 1px var(--line-leaf);
}

.page-about .about-next__label {
  margin: 0 0 14px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.2em;
  color: var(--accent-cyan);
}

.page-about .about-next__links {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

/* ---------- 增强布局 ---------- */
@media (min-width: 760px) {
  .page-about .team-split {
    grid-template-columns: minmax(180px, 240px) minmax(0, 1fr);
    align-items: center;
  }

  .page-about .team-donut {
    justify-self: start;
  }
}

@media (min-width: 980px) {
  .page-about .about-body {
    grid-template-columns: var(--about-rail-w) minmax(0, 1fr);
    gap: clamp(34px, 4vw, 74px);
  }

  .page-about .about-rail {
    position: sticky;
    top: clamp(24px, 8vh, 80px);
    align-self: start;
  }

  .page-about .about-rail__list {
    flex-direction: column;
    gap: 0;
    overflow: visible;
    padding-bottom: 0;
  }

  .page-about .about-rail__link {
    width: 100%;
    padding: 10px 12px;
    border: 0;
    border-left: 2px solid transparent;
    border-radius: 0;
    background: transparent;
  }

  .page-about .about-rail__item + .about-rail__item .about-rail__link {
    border-top: var(--about-hair);
  }

  .page-about .about-rail__link:hover,
  .page-about .about-rail__link:focus-visible {
    border-left-color: var(--accent-cyan);
    background: var(--glass-panel);
  }

  .page-about .about-rail__num {
    font-size: 11.5px;
  }

  .page-about .about-chapter:target::before {
    left: -24px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-rail__link,
  .page-about .note-toggle,
  .page-about .about-chapter .prose a {
    transition: none;
  }
}