.page-about {
  display: block;
  position: relative;
  overflow-x: clip;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  padding: clamp(32px, 6vw, 82px) 0 clamp(26px, 4vw, 52px);
  border-bottom: 1px solid var(--line-soft);
  overflow: hidden;
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  top: -24%;
  right: -14%;
  width: 62%;
  height: 150%;
  z-index: 0;
  pointer-events: none;
  background: radial-gradient(circle at 50% 50%, rgba(43, 224, 200, 0.14), rgba(43, 224, 200, 0) 64%);
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  background-image:
    repeating-linear-gradient(90deg, rgba(43, 224, 200, 0.07) 0 1px, transparent 1px 120px),
    repeating-linear-gradient(0deg, rgba(43, 224, 200, 0.07) 0 1px, transparent 1px 80px);
  -webkit-mask-image: radial-gradient(120% 92% at 86% 14%, #000 0%, transparent 68%);
  mask-image: radial-gradient(120% 92% at 86% 14%, #000 0%, transparent 68%);
}

.page-about .about-hero > .shell {
  position: relative;
  z-index: 1;
}

.page-about .about-hero .eyebrow {
  margin: 18px 0 12px;
}

.page-about .about-hero .display {
  margin: 0 0 18px;
  max-width: 14ch;
  line-height: 1.02;
}

.page-about .about-hero .lede {
  margin: 0;
}

.page-about .about-hero-facts {
  display: flex;
  flex-wrap: wrap;
  gap: 12px 26px;
  margin: clamp(22px, 3vw, 38px) 0 0;
  padding: 0;
  list-style: none;
}

.page-about .about-hero-facts li {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 11px;
  letter-spacing: 0.13em;
  text-transform: uppercase;
  color: var(--muted);
}

.page-about .about-hero-facts li::before {
  content: "";
  flex: none;
  width: 6px;
  height: 6px;
  background: var(--lime);
  transform: rotate(45deg);
}

/* ---------- 分栏工作区 ---------- */
.page-about .about-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 0;
  padding-top: clamp(24px, 4vw, 52px);
}

.page-about .about-rail {
  display: none;
}

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

/* ---------- 侧栏章节索引 ---------- */
.page-about .about-rail .toc {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 24px;
  border-left: 1px solid var(--line-soft);
}

.page-about .about-rail .toc li {
  position: relative;
}

.page-about .about-rail .toc-link {
  display: flex;
  flex-direction: column;
  gap: 3px;
  padding-left: 13px;
  position: relative;
  text-decoration: none;
  color: var(--muted);
  transition: color var(--dur) var(--ease);
}

.page-about .about-rail .toc-link::before {
  content: "";
  position: absolute;
  left: -1px;
  top: 4px;
  width: 1px;
  height: 14px;
  background: transparent;
  transition: background var(--dur) var(--ease), height var(--dur) var(--ease), box-shadow var(--dur) var(--ease);
}

.page-about .about-rail .toc-link:hover {
  color: var(--text);
}

.page-about .about-rail .toc-link.is-current {
  color: var(--cyan);
}

.page-about .about-rail .toc-link.is-current::before {
  background: var(--cyan);
  height: 24px;
  box-shadow: 0 0 12px rgba(43, 224, 200, 0.7);
}

.page-about .about-rail .toc-num {
  font-family: var(--font-mono);
  font-size: 15px;
  font-weight: 600;
  letter-spacing: 0.04em;
  font-variant-numeric: tabular-nums;
  line-height: 1;
}

.page-about .about-rail .toc-label {
  font-size: 10px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  line-height: 1.2;
}

/* ---------- 章节骨架 ---------- */
.page-about .about-sec {
  position: relative;
  padding: clamp(30px, 5vw, 64px) 0;
  border-bottom: 1px solid var(--line-soft);
  scroll-margin-top: calc(var(--header-h) + 22px);
}

.page-about .about-sec:last-child {
  border-bottom: none;
  padding-bottom: clamp(24px, 4vw, 48px);
}

.page-about .sec-head {
  display: grid;
  gap: 12px;
  margin-bottom: clamp(20px, 3vw, 34px);
}

.page-about .sec-kicker {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--cyan);
}

.page-about .sec-title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 400;
  font-size: clamp(26px, 5vw, 46px);
  letter-spacing: 0.02em;
  text-transform: uppercase;
  line-height: 1.08;
  color: var(--text);
}

/* ---------- 正文与展签 ---------- */
.page-about .prose p {
  margin: 0 0 16px;
  font-size: 15px;
  line-height: 1.78;
  color: var(--text-soft);
  max-width: 68ch;
}

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

.page-about .prose-lead {
  margin: 0 0 clamp(20px, 3vw, 30px);
  font-size: 15px;
  line-height: 1.78;
  color: var(--text-soft);
  max-width: 68ch;
}

.page-about .prose-note {
  margin: clamp(18px, 3vw, 28px) 0 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--muted);
  max-width: 68ch;
}

.page-about .plate {
  position: relative;
  margin: clamp(20px, 3vw, 30px) 0 0;
  padding: 16px 18px 16px 20px;
  max-width: 68ch;
  border: 1px solid var(--line-soft);
  border-left: 2px solid var(--line-strong);
  background: linear-gradient(90deg, rgba(11, 42, 36, 0.6), rgba(11, 42, 36, 0));
  font-size: 13px;
  line-height: 1.72;
  color: var(--text-soft);
  transition: transform var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.page-about .plate:hover {
  transform: translateX(3px);
  border-left-color: var(--cyan);
}

.page-about .plate-num {
  display: block;
  margin-bottom: 6px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.18em;
  color: var(--lime);
}

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

.page-about .about-figure img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
  border: 1px solid var(--line);
  background: var(--moss);
}

.page-about .about-figure figcaption {
  margin-top: 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--muted);
}

/* ---------- 覆盖范围数据格 ---------- */
.page-about .about-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: clamp(4px, 1vw, 10px) 0 0;
  border: 1px solid var(--line-soft);
  background: var(--line-soft);
}

.page-about .about-stat {
  display: grid;
  gap: 8px;
  padding: 18px 16px;
  background: var(--moss);
}

.page-about .about-stat-num {
  font-family: var(--font-mono);
  font-size: clamp(24px, 6vw, 34px);
  font-weight: 700;
  line-height: 1;
  letter-spacing: 0.01em;
  color: var(--lime);
  font-variant-numeric: tabular-nums;
}

.page-about .about-stat-label {
  font-size: 11px;
  letter-spacing: 0.13em;
  text-transform: uppercase;
  color: var(--muted);
  line-height: 1.3;
}

/* ---------- 入库流程 ---------- */
.page-about .about-steps {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 14px;
}

.page-about .step {
  display: grid;
  gap: 8px;
  padding: 20px 18px 22px;
  background: var(--moss);
  border: 1px solid var(--line);
  clip-path: var(--clip-cut-sm);
  transition: background var(--dur) var(--ease), transform var(--dur) var(--ease);
}

.page-about .step:hover {
  background: var(--moss-lift);
  transform: translateY(-2px);
}

.page-about .step-num {
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.18em;
  color: var(--cyan);
}

.page-about .step-title {
  margin: 0;
  font-size: 17px;
  font-weight: 500;
  letter-spacing: 0.02em;
  color: var(--text);
}

.page-about .step-body {
  margin: 0;
  font-size: 14px;
  line-height: 1.7;
  color: var(--text-soft);
}

/* ---------- 团队分工 ---------- */
.page-about .about-teams {
  display: grid;
  gap: 14px;
}

.page-about .team-card {
  display: grid;
  gap: 10px;
  padding: 22px 18px;
  border: 1px solid var(--line);
  border-top: 2px solid var(--cyan);
  background: linear-gradient(180deg, rgba(13, 27, 51, 0.85), rgba(6, 15, 20, 0.4));
  transition: border-top-color var(--dur) var(--ease), transform var(--dur) var(--ease);
}

.page-about .team-card:hover {
  transform: translateY(-3px);
  border-top-color: var(--lime);
}

.page-about .team-tag {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--muted);
}

.page-about .team-title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 400;
  font-size: 22px;
  letter-spacing: 0.03em;
  text-transform: uppercase;
  color: var(--text);
}

.page-about .team-body {
  margin: 0;
  font-size: 14px;
  line-height: 1.72;
  color: var(--text-soft);
}

/* ---------- 纵向时间轴 ---------- */
.page-about .about-timeline {
  list-style: none;
  margin: clamp(20px, 3vw, 32px) 0 0;
  padding: 0 0 0 26px;
  position: relative;
  display: grid;
  gap: 28px;
}

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  left: 4px;
  top: 10px;
  bottom: 10px;
  width: 1px;
  background: linear-gradient(180deg, var(--cyan), var(--lime) 58%, rgba(43, 224, 200, 0.08));
}

.page-about .tl-item {
  position: relative;
}

.page-about .tl-item::before {
  content: "";
  position: absolute;
  left: -26px;
  top: 6px;
  width: 9px;
  height: 9px;
  background: var(--ink);
  border: 2px solid var(--cyan);
  transform: rotate(45deg);
}

.page-about .tl-item:last-child::before {
  border-color: var(--lime);
  background: var(--lime);
  box-shadow: 0 0 14px rgba(198, 242, 78, 0.55);
}

.page-about .tl-idx {
  display: block;
  margin-bottom: 6px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--cyan);
}

.page-about .tl-title {
  margin: 0 0 6px;
  font-family: var(--font-display);
  font-weight: 400;
  font-size: 22px;
  letter-spacing: 0.03em;
  text-transform: uppercase;
  color: var(--text);
}

.page-about .tl-body {
  margin: 0;
  font-size: 14px;
  line-height: 1.72;
  color: var(--text-soft);
  max-width: 68ch;
}

/* ---------- 折线图 ---------- */
.page-about .about-spark {
  display: block;
  width: 100%;
  height: auto;
  margin: clamp(24px, 3vw, 36px) 0 0;
  border: 1px solid var(--line);
  background: linear-gradient(180deg, rgba(11, 42, 36, 0.6), rgba(6, 15, 20, 0));
}

/* ---------- 更新日历 ---------- */
.page-about .about-calendar {
  display: grid;
  gap: 1px;
  border: 1px solid var(--line-soft);
  background: var(--line-soft);
}

.page-about .cal {
  display: grid;
  gap: 10px;
  padding: 22px 18px 26px;
  background: var(--ink);
  position: relative;
}

.page-about .cal::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  width: 100%;
  height: 2px;
}

.page-about .cal--cyan::before { background: var(--cyan); }
.page-about .cal--lime::before { background: var(--lime); }
.page-about .cal--signal::before { background: var(--signal); }

.page-about .cal-tag {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--muted);
}

.page-about .cal--cyan .cal-tag { color: var(--cyan); }
.page-about .cal--lime .cal-tag { color: var(--lime); }
.page-about .cal--signal .cal-tag { color: var(--signal); }

.page-about .cal-title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 400;
  font-size: 22px;
  letter-spacing: 0.03em;
  text-transform: uppercase;
  color: var(--text);
}

.page-about .cal-body {
  margin: 0;
  font-size: 14px;
  line-height: 1.72;
  color: var(--text-soft);
}

/* ---------- 页尾推进 ---------- */
.page-about .about-next {
  margin: clamp(28px, 4vw, 44px) 0 0;
  padding: clamp(22px, 3vw, 32px);
  border: 1px solid var(--line-strong);
  background: linear-gradient(115deg, rgba(11, 42, 36, 0.9), rgba(13, 27, 51, 0.85));
  clip-path: var(--clip-cut-lg);
}

.page-about .about-next-label {
  margin: 0 0 16px;
  font-size: 11px;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--cyan);
}

.page-about .about-next-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.page-about .about-next-note {
  margin: 18px 0 0;
  font-size: 13px;
  line-height: 1.75;
  color: var(--text-soft);
  max-width: 68ch;
}

.page-about .about-next-note a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(43, 224, 200, 0.4);
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.page-about .about-next-note a:hover {
  color: var(--lime);
  border-bottom-color: var(--lime);
}

/* ---------- 断点 ---------- */
@media (min-width: 640px) {
  .page-about .about-stats {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .about-stat {
    padding: 22px 18px;
  }
}

@media (min-width: 760px) {
  .page-about .about-teams {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .about-steps {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .about-steps li:last-child:nth-child(odd) {
    grid-column: 1 / -1;
  }

  .page-about .about-calendar {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

@media (min-width: 900px) {
  .page-about .about-layout {
    grid-template-columns: 72px minmax(0, 1fr);
    gap: 0 44px;
  }

  .page-about .about-rail {
    display: block;
    position: sticky;
    top: calc(var(--header-h) + 32px);
    align-self: start;
  }

  .page-about .about-hero .display {
    max-width: 16ch;
  }
}

@media (min-width: 1200px) {
  .page-about .about-layout {
    grid-template-columns: 84px minmax(0, 1fr);
    gap: 0 56px;
  }

  .page-about .about-rail .toc-num {
    font-size: 16px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .step,
  .page-about .team-card,
  .page-about .plate {
    transition: none;
  }
}