.page-about {
  --about-rail-w: 72px;
  --about-accent-ink: #0B6F68;
  background: var(--abyss-900);
  color: var(--fg);
  overflow-x: hidden;
}

.page-about .container {
  padding-inline: 20px;
}

/* ============ 首屏 ============ */
.page-about .about-hero {
  position: relative;
  padding: 28px 0 56px;
  background:
    radial-gradient(120% 90% at 84% 0%, rgba(63, 227, 210, .13), transparent 58%),
    radial-gradient(90% 70% at 4% 100%, rgba(255, 138, 61, .10), transparent 62%),
    var(--abyss-900);
  border-bottom: 2px solid var(--abyss-500);
}

.page-about .about-hero-grid {
  display: grid;
  gap: 32px;
  margin-top: 24px;
}

.page-about .about-hero-kicker {
  font-size: 13px;
  letter-spacing: .1em;
  color: var(--neon);
  margin: 0 0 14px;
}

.page-about .about-h1 {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(30px, 6vw, 54px);
  line-height: 1.08;
  letter-spacing: -.02em;
  margin: 0 0 20px;
  color: #fff;
}

.page-about .about-lead {
  font-size: 17px;
  line-height: 1.78;
  color: var(--fg-soft);
  max-width: 34em;
  margin: 0;
}

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

.page-about .about-dossier {
  background: var(--abyss-700);
  border: 2px solid var(--neon);
  border-radius: var(--radius-card);
  box-shadow: 6px 6px 0 0 #04101C;
  padding: 22px 22px 12px;
}

.page-about .about-dossier-title {
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 600;
  letter-spacing: .1em;
  color: var(--neon);
  margin: 0 0 14px;
}

.page-about .about-facts {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .about-facts li {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 16px;
  padding: 12px 0;
  border-top: 1px solid var(--abyss-500);
}

.page-about .about-facts li:first-child {
  border-top: 0;
}

.page-about .about-fact-key {
  font-size: 14px;
  line-height: 1.5;
  color: var(--fg-soft);
}

.page-about .about-fact-val {
  font-size: 14px;
  font-weight: 600;
  color: #fff;
  white-space: nowrap;
}

/* ============ 主体骨架 ============ */
.page-about .about-shell {
  display: grid;
  gap: 28px;
  padding-top: 40px;
  padding-bottom: 64px;
}

.page-about .about-rail {
  display: flex;
  gap: 8px;
  overflow-x: auto;
  padding-bottom: 6px;
  scrollbar-width: none;
}

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

.page-about .about-rail-link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  min-height: 48px;
  padding: 0 16px;
  border: 2px solid var(--abyss-500);
  border-radius: var(--radius-pill);
  background: var(--abyss-700);
  color: var(--fg-soft);
  font-size: 14px;
  text-decoration: none;
  white-space: nowrap;
  transition: color .16s var(--ease), border-color .16s var(--ease), background-color .16s var(--ease);
}

.page-about .about-rail-link:hover,
.page-about .about-rail-link:focus-visible {
  border-color: var(--neon);
  color: var(--neon);
}

.page-about .about-rail-num {
  font-size: 13px;
  font-weight: 600;
  color: var(--neon);
}

.page-about .about-main {
  display: flex;
  flex-direction: column;
  gap: 32px;
  min-width: 0;
}

/* ============ 章节容器 ============ */
.page-about .about-sec {
  position: relative;
  border: 2px solid var(--abyss-500);
  border-radius: var(--radius-card);
  padding: 26px 20px 30px;
  scroll-margin-top: calc(var(--header-h) + 24px);
}

.page-about .about-sec--ink {
  background: var(--abyss-700);
}

.page-about .about-sec--deep {
  background: var(--abyss-900);
  border-color: var(--neon);
}

.page-about .about-sec--paper {
  background: var(--paper);
  border-color: var(--ink);
  box-shadow: 6px 6px 0 0 var(--abyss-500);
  color: var(--ink);
}

.page-about .about-sec-head {
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin-bottom: 22px;
  padding-bottom: 18px;
  border-bottom: 2px solid var(--abyss-500);
}

.page-about .about-sec--paper .about-sec-head {
  border-bottom-color: var(--ink);
}

.page-about .about-sec-num {
  font-size: 13px;
  font-weight: 600;
  letter-spacing: .1em;
  color: var(--neon);
  margin: 0;
}

.page-about .about-sec--paper .about-sec-num {
  color: var(--about-accent-ink);
}

.page-about .about-sec-title {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(21px, 3vw, 28px);
  line-height: 1.22;
  letter-spacing: -.01em;
  margin: 0;
  color: #fff;
}

.page-about .about-sec--paper .about-sec-title {
  color: var(--ink);
}

.page-about .about-sec-lead {
  font-size: 16px;
  line-height: 1.75;
  color: var(--fg-soft);
  max-width: 42em;
  margin: 0;
}

.page-about .about-sec--paper .about-sec-lead {
  color: var(--ink-soft);
}

.page-about .about-p {
  font-size: 16px;
  line-height: 1.78;
  color: var(--fg-soft);
  margin: 0 0 4px;
  max-width: 42em;
}

.page-about .about-sec--paper .about-p {
  color: var(--ink-soft);
}

.page-about .about-note {
  margin: 24px 0 0;
  padding-top: 18px;
  border-top: 1px solid var(--abyss-500);
  font-size: 14px;
  line-height: 1.75;
  color: var(--slate);
  max-width: 44em;
}

.page-about .about-sec--paper .about-note {
  border-top-color: rgba(20, 25, 30, .18);
  color: var(--ink-soft);
}

.page-about .about-note a,
.page-about .about-card-ref a {
  color: var(--neon);
  text-underline-offset: 3px;
}

.page-about .about-sec--paper .about-note a,
.page-about .about-sec--paper .about-card-ref a {
  color: var(--about-accent-ink);
}

/* ============ 结构图 ============ */
.page-about .about-arch {
  margin-top: 24px;
}

.page-about .about-arch-root {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 16px 18px;
  border: 2px solid var(--neon);
  border-radius: var(--radius-card);
  background: var(--abyss-900);
  margin: 0;
}

.page-about .about-arch-root-label {
  font-size: 13px;
  letter-spacing: .06em;
  color: var(--neon);
}

.page-about .about-arch-root-name {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 17px;
  color: #fff;
}

.page-about .about-arch-list {
  list-style: none;
  margin: 26px 0 0;
  padding: 0;
  position: relative;
  display: grid;
  gap: 12px;
}

.page-about .about-arch-node {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 14px 14px 16px;
  border: 2px solid var(--abyss-500);
  border-radius: var(--radius-card);
  background: rgba(8, 25, 42, .7);
  transition: border-color .2s var(--ease), transform .2s var(--ease);
}

.page-about .about-arch-node:hover,
.page-about .about-arch-node:focus-within {
  border-color: var(--neon);
  transform: translateY(-3px);
}

.page-about .about-arch-node-num {
  font-size: 12px;
  font-weight: 600;
  letter-spacing: .08em;
  color: var(--neon);
}

.page-about .about-arch-node-name {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 16px;
  color: #fff;
}

.page-about .about-arch-node-desc {
  font-size: 14px;
  line-height: 1.65;
  color: var(--fg-soft);
}

/* ============ 时间线 ============ */
.page-about .about-tl-figure {
  margin: 0 0 28px;
}

.page-about .about-tl-figure img {
  display: block;
  width: 100%;
  height: auto;
  border: 2px solid var(--ink);
  border-radius: var(--radius-card);
  object-fit: cover;
}

.page-about .about-tl-figure .media-caption {
  display: block;
  margin-top: 10px;
  font-size: 13px;
  line-height: 1.6;
  color: var(--ink-soft);
}

.page-about .about-timeline {
  list-style: none;
  margin: 0;
  padding: 0 0 0 30px;
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  left: 7px;
  top: 10px;
  bottom: 10px;
  width: 2px;
  background: linear-gradient(180deg, var(--about-accent-ink), rgba(20, 25, 30, .25));
}

.page-about .about-tl-summary {
  position: relative;
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 14px 16px;
  min-height: 48px;
  border: 2px solid var(--ink);
  border-radius: var(--radius-card);
  background: var(--paper-soft);
  cursor: pointer;
  list-style: none;
  transition: border-color .2s var(--ease), background-color .2s var(--ease);
}

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

.page-about .about-tl-summary:hover {
  border-color: var(--about-accent-ink);
}

.page-about .about-tl-summary::before {
  content: "";
  position: absolute;
  left: -30px;
  top: 50%;
  transform: translateY(-50%);
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--paper);
  border: 2px solid var(--mist);
  transition: background-color .22s var(--ease), border-color .22s var(--ease), box-shadow .22s var(--ease);
}

.page-about .about-tl-details[open] > .about-tl-summary::before {
  background: var(--about-accent-ink);
  border-color: var(--about-accent-ink);
  box-shadow: 0 0 0 4px rgba(11, 111, 104, .18);
}

.page-about .about-tl-year {
  flex: none;
  font-size: 14px;
  font-weight: 600;
  color: var(--about-accent-ink);
}

.page-about .about-tl-title {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 16px;
  color: var(--ink);
}

.page-about .about-tl-toggle {
  margin-left: auto;
  flex: none;
  width: 10px;
  height: 10px;
  border-right: 2px solid var(--ink-soft);
  border-bottom: 2px solid var(--ink-soft);
  transform: rotate(45deg);
  transition: transform .22s var(--ease);
}

.page-about .about-tl-details[open] .about-tl-toggle {
  transform: rotate(-135deg);
}

.page-about .about-tl-body {
  padding: 14px 16px 6px;
  font-size: 15px;
  line-height: 1.78;
  color: var(--ink-soft);
}

.page-about .about-tl-body p {
  margin: 0;
}

/* ============ 栏目卡片 ============ */
.page-about .about-cards {
  display: grid;
  gap: 14px;
}

.page-about .about-card {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 18px 18px 16px;
  border: 2px solid var(--ink);
  border-radius: var(--radius-card);
  background: var(--paper-soft);
}

.page-about .about-card-tag {
  font-size: 12px;
  font-weight: 600;
  letter-spacing: .08em;
  color: var(--about-accent-ink);
}

.page-about .about-card-title {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 18px;
  line-height: 1.3;
  margin: 0;
  color: var(--ink);
}

.page-about .about-card-summary {
  font-size: 15px;
  line-height: 1.72;
  color: var(--ink-soft);
  margin: 0;
}

.page-about .about-card-ref {
  margin: auto 0 0;
  padding-top: 12px;
  border-top: 1px solid rgba(20, 25, 30, .16);
  font-size: 13px;
  color: var(--ink-soft);
}

/* ============ 能力边界 ============ */
.page-about .about-bound {
  display: grid;
  gap: 20px;
}

.page-about .about-bound-col {
  border: 2px solid var(--abyss-500);
  border-radius: var(--radius-card);
  padding: 18px 18px 20px;
  background: rgba(8, 25, 42, .6);
}

.page-about .about-bound-col--out {
  border-color: rgba(255, 107, 94, .5);
}

.page-about .about-bound-title {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 16px;
  letter-spacing: .02em;
  margin: 0 0 14px;
  color: #fff;
}

.page-about .about-bound-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.page-about .about-bound-list li {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  font-size: 15px;
  line-height: 1.7;
  color: var(--fg-soft);
}

.page-about .about-bound-list .status-dot {
  margin-top: 9px;
  flex: none;
}

/* ============ 团队 ============ */
.page-about .about-team {
  display: grid;
  gap: 24px;
}

.page-about .about-team-list {
  list-style: none;
  margin: 0 0 20px;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.page-about .about-team-item {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 4px 12px;
  padding: 14px 0 0;
  border-top: 2px solid var(--ink);
}

.page-about .about-team-role {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 16px;
  color: var(--ink);
}

.page-about .about-team-count {
  font-size: 14px;
  font-weight: 600;
  color: var(--about-accent-ink);
  text-align: right;
}

.page-about .about-team-item p {
  grid-column: 1 / -1;
  margin: 0;
  font-size: 15px;
  line-height: 1.7;
  color: var(--ink-soft);
}

.page-about .about-team-media {
  margin: 0;
}

.page-about .about-team-media img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 9 / 7;
  object-fit: cover;
  border: 2px solid var(--ink);
  border-radius: var(--radius-card);
}

/* ============ 指标 ============ */
.page-about .about-sec--metrics {
  overflow: hidden;
}

.page-about .about-metrics-bg {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: .18;
  pointer-events: none;
  z-index: 0;
}

.page-about .about-metrics-inner {
  position: relative;
  z-index: 1;
}

.page-about .about-metrics {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 14px;
}

.page-about .about-metric {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 20px 18px 16px;
  border: 2px solid var(--abyss-500);
  border-left: 6px solid var(--neon);
  border-radius: var(--radius-card);
  background: rgba(16, 42, 66, .82);
}

.page-about .about-metric-num {
  font-size: clamp(28px, 5vw, 38px);
  font-weight: 700;
  line-height: 1.1;
  color: #fff;
  letter-spacing: -.01em;
}

.page-about .about-metric-label {
  font-size: 14px;
  line-height: 1.5;
  color: var(--fg-soft);
}

.page-about .about-metric-detail {
  margin-top: 10px;
  border-top: 1px solid var(--abyss-500);
  padding-top: 10px;
}

.page-about .about-metric-detail summary {
  display: inline-flex;
  align-items: center;
  min-height: 32px;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: .04em;
  color: var(--neon);
  cursor: pointer;
  list-style: none;
}

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

.page-about .about-metric-detail summary::before {
  content: "+";
  display: inline-block;
  width: 16px;
  color: var(--neon);
}

.page-about .about-metric-detail[open] summary::before {
  content: "−";
}

.page-about .about-metric-detail p {
  margin: 8px 0 0;
  font-size: 14px;
  line-height: 1.7;
  color: var(--fg-soft);
}

/* ============ 平板与桌面 ============ */
@media (min-width: 700px) {
  .page-about .container {
    padding-inline: 32px;
  }

  .page-about .about-sec {
    padding: 34px 32px 38px;
  }

  .page-about .about-cards {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 16px;
  }

  .page-about .about-bound {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 18px;
  }

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

@media (min-width: 900px) {
  .page-about .about-hero {
    padding: 40px 0 76px;
  }

  .page-about .about-hero-grid {
    grid-template-columns: 7fr 5fr;
    gap: 52px;
    align-items: start;
    margin-top: 36px;
  }

  .page-about .about-shell {
    grid-template-columns: var(--about-rail-w) minmax(0, 1fr);
    gap: 40px;
    padding-top: 64px;
    padding-bottom: 96px;
  }

  .page-about .about-rail {
    position: sticky;
    top: calc(var(--header-h) + 28px);
    flex-direction: column;
    gap: 10px;
    overflow: visible;
    padding-bottom: 0;
  }

  .page-about .about-rail-link {
    width: 48px;
    height: 48px;
    padding: 0;
    justify-content: center;
  }

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

  .page-about .about-main {
    gap: 56px;
  }

  .page-about .about-sec {
    padding: 42px 44px 46px;
  }

  .page-about .about-arch-list {
    grid-template-columns: repeat(5, minmax(0, 1fr));
    gap: 14px;
    margin-top: 30px;
  }

  .page-about .about-arch-list::before {
    content: "";
    position: absolute;
    left: 8%;
    right: 8%;
    top: -14px;
    height: 2px;
    background: var(--abyss-500);
  }

  .page-about .about-arch-node::before {
    content: "";
    position: absolute;
    left: 50%;
    top: -14px;
    width: 2px;
    height: 14px;
    background: var(--abyss-500);
    transform: translateX(-1px);
  }

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

  .page-about .about-cards .about-card:nth-child(even) {
    transform: translateY(18px);
  }

  .page-about .about-team {
    grid-template-columns: 7fr 5fr;
    gap: 40px;
    align-items: start;
  }

  .page-about .about-team-media img {
    aspect-ratio: 9 / 7;
  }
}

@media (min-width: 1180px) {
  .page-about .about-cards {
    grid-template-columns: repeat(5, minmax(0, 1fr));
  }

  .page-about .about-cards .about-card:nth-child(even) {
    transform: translateY(20px);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-arch-node,
  .page-about .about-tl-summary,
  .page-about .about-tl-toggle,
  .page-about .about-rail-link,
  .page-about .about-tl-summary::before {
    transition: none;
  }

  .page-about .about-arch-node:hover,
  .page-about .about-arch-node:focus-within,
  .page-about .about-cards .about-card:nth-child(even) {
    transform: none;
  }
}