.page-about {
  --about-rail: 78px;
  --about-hair: rgba(242, 231, 201, .10);
}

/* ---------- 面包屑 ---------- */
.page-about .about-crumbs {
  padding-top: clamp(16px, 3vw, 28px);
}
.page-about .breadcrumb {
  font-size: 13px;
  color: var(--muted);
}
.page-about .breadcrumb-list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  margin: 0;
  padding: 0;
  list-style: none;
}
.page-about .breadcrumb-list li {
  display: flex;
  align-items: center;
  gap: 8px;
}
.page-about .breadcrumb-list li + li::before {
  content: "/";
  color: var(--line);
}
.page-about .breadcrumb-list a {
  color: var(--muted);
  text-decoration: none;
}
.page-about .breadcrumb-list a:hover {
  color: var(--gold-hi);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  margin-top: clamp(14px, 3vw, 24px);
  padding: clamp(30px, 6vw, 68px) 0 clamp(34px, 6vw, 72px);
  background:
    radial-gradient(120% 90% at 84% 0%, rgba(60, 140, 114, .22), transparent 62%),
    radial-gradient(80% 70% at 6% 100%, rgba(201, 162, 39, .10), transparent 65%),
    linear-gradient(180deg, var(--bg-2), var(--bg) 80%);
  border-top: 1px solid var(--line-faint);
  border-bottom: 1px solid var(--line-faint);
}
.page-about .about-hero-grid {
  display: grid;
  gap: clamp(24px, 4vw, 48px);
  grid-template-columns: 1fr;
}
.page-about .about-hero-copy h1 {
  margin: 14px 0 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(28px, 5vw, 50px);
  line-height: 1.24;
  letter-spacing: .02em;
  color: var(--ink);
  max-width: 20ch;
}
.page-about .about-hero-copy .lede {
  margin: 18px 0 0;
  font-size: 16px;
  line-height: 1.85;
  color: var(--ink);
  opacity: .88;
  max-width: 40ch;
}
.page-about .about-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: clamp(22px, 3.4vw, 34px);
}

/* 概况悬浮岛 */
.page-about .about-glance {
  position: relative;
  align-self: start;
  padding: clamp(18px, 2.6vw, 26px);
  border: 1px solid var(--gold-soft);
  border-radius: var(--r-lg);
  background:
    linear-gradient(180deg, rgba(5, 19, 15, .92), rgba(16, 49, 42, .82));
  box-shadow: 0 26px 60px rgba(0, 0, 0, .38);
}
.page-about .about-glance::after {
  content: "";
  position: absolute;
  inset: 6px;
  border: 1px solid var(--line-faint);
  border-radius: var(--r);
  pointer-events: none;
}
.page-about .about-glance-title {
  position: relative;
  z-index: 1;
  display: flex;
  align-items: center;
  gap: 8px;
  margin: 0 0 6px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .16em;
  color: var(--gold);
  text-transform: uppercase;
}
.page-about .about-glance-list {
  position: relative;
  z-index: 1;
  margin: 0;
  padding: 0;
  list-style: none;
}
.page-about .about-glance-list li {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 14px;
  padding: 10px 0;
  border-bottom: 1px dashed var(--line-faint);
}
.page-about .about-glance-list li:last-child {
  border-bottom: 0;
}
.page-about .about-glance-num {
  font-family: var(--font-mono);
  font-weight: 500;
  font-size: 21px;
  letter-spacing: .04em;
  color: var(--gold-hi);
}
.page-about .about-glance-key {
  font-size: 13px;
  color: var(--muted);
  text-align: right;
}

/* ---------- 章节索引 ---------- */
.page-about .about-toc {
  padding-top: clamp(20px, 3.4vw, 30px);
}
.page-about .toc-title {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .16em;
  color: var(--muted);
}
.page-about .toc-list {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  margin: 0;
  padding: 1px;
  list-style: none;
  background: var(--line-faint);
  border: 1px solid var(--line-faint);
  border-radius: var(--r);
}
.page-about .toc-list li {
  background: var(--bg);
}
.page-about .toc-list a {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 12px 14px;
  font-size: 14px;
  color: var(--ink);
  text-decoration: none;
  transition: background .2s ease, color .2s ease;
}
.page-about .toc-list a:hover {
  background: var(--bg-2);
  color: var(--gold-hi);
}
.page-about .about-toc-num {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--gold);
}

/* ---------- 章节骨架 ---------- */
.page-about .about-section {
  padding: clamp(44px, 7vw, 90px) 0;
  border-bottom: 1px solid var(--line-faint);
}
.page-about .about-section .section-head {
  border-left: 2px solid var(--gold);
  padding-left: clamp(14px, 2vw, 20px);
  margin-bottom: clamp(24px, 3.6vw, 38px);
}
.page-about .about-section .section-index {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .18em;
  color: var(--gold);
}
.page-about .about-section .section-title {
  margin: 8px 0 6px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(22px, 3.4vw, 34px);
  line-height: 1.3;
  letter-spacing: .02em;
  color: var(--ink);
}
.page-about .about-section .section-note {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .06em;
  color: var(--muted);
}

.page-about .about-prose p {
  margin: 0 0 16px;
  font-size: 16px;
  line-height: 1.85;
  color: var(--ink);
  opacity: .9;
  max-width: 38em;
}
.page-about .about-prose p:last-child {
  margin-bottom: 0;
}
.page-about .about-lead-in {
  margin: 0 0 clamp(22px, 3.4vw, 34px);
  font-size: 16px;
  line-height: 1.85;
  color: var(--ink);
  opacity: .9;
  max-width: 38em;
}

/* ---------- 01 起点 ---------- */
.page-about .about-two-col {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(22px, 3.4vw, 34px);
}
.page-about .about-side-card {
  color: var(--bg);
  padding: clamp(20px, 2.8vw, 28px);
}
.page-about .about-side-label {
  margin: 0 0 16px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .14em;
  opacity: .7;
}
.page-about .about-dl {
  display: grid;
  gap: 14px;
  margin: 0;
}
.page-about .about-dl > div {
  padding-bottom: 14px;
  border-bottom: 1px solid rgba(11, 33, 28, .18);
}
.page-about .about-dl > div:last-child {
  padding-bottom: 0;
  border-bottom: 0;
}
.page-about .about-dl dt {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .12em;
  opacity: .68;
  margin-bottom: 5px;
}
.page-about .about-dl dd {
  margin: 0;
  font-size: 15px;
  font-weight: 600;
  line-height: 1.7;
}

/* ---------- 02 时间线 ---------- */
.page-about .about-timeline-figure {
  margin: 0 0 clamp(24px, 4vw, 40px);
}
.page-about .about-timeline-figure img,
.page-about .about-tax-figure img,
.page-about .about-team-figure img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  object-fit: cover;
  border-radius: var(--r-lg);
  border: 1px solid var(--line-faint);
}
.page-about .figure-cap {
  display: block;
  margin-top: 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .06em;
  color: var(--muted);
}

.page-about .about-timeline {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(20px, 3vw, 32px);
}
.page-about .about-rail {
  display: flex;
  gap: 10px;
  overflow-x: auto;
}
.page-about .about-rail-item {
  flex: none;
  padding: 6px 12px;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: .12em;
  color: var(--muted);
  border: 1px solid var(--line-faint);
  border-radius: var(--r);
  background: var(--bg-2);
}
.page-about .about-rail-item.is-current {
  color: var(--deep);
  background: var(--gold);
  border-color: var(--gold);
}

.page-about .about-track {
  min-width: 0;
}
.page-about .about-node {
  position: relative;
  margin-bottom: 16px;
  border: 1px solid var(--line-faint);
  border-left: 3px solid var(--gold-soft);
  border-radius: var(--r-lg);
  background: linear-gradient(180deg, var(--bg-2), var(--bg));
  transition: border-color .25s ease, background .25s ease;
}
.page-about .about-node[open] {
  border-left-color: var(--gold);
}
.page-about .about-node:hover {
  border-color: var(--line);
}
.page-about .about-node-summary {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px 14px;
  padding: 16px 18px;
  cursor: pointer;
  list-style: none;
}
.page-about .about-node-summary::-webkit-details-marker {
  display: none;
}
.page-about .about-node-summary::after {
  content: "+";
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 18px;
  color: var(--gold);
}
.page-about .about-node[open] .about-node-summary::after {
  content: "–";
}
.page-about .about-node-ver {
  font-family: var(--font-mono);
  font-size: 15px;
  font-weight: 500;
  letter-spacing: .1em;
  color: var(--gold-hi);
}
.page-about .about-node-title {
  font-size: 16px;
  font-weight: 700;
  color: var(--ink);
}
.page-about .about-node-body {
  padding: 0 18px 18px;
  border-top: 1px solid var(--line-faint);
}
.page-about .about-node-body p {
  margin: 14px 0 12px;
  font-size: 15px;
  line-height: 1.85;
  color: var(--ink);
  opacity: .86;
  max-width: 40em;
}
.page-about .about-node-list {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 8px;
}
.page-about .about-node-list li {
  position: relative;
  padding-left: 18px;
  font-size: 14px;
  line-height: 1.7;
  color: var(--muted);
}
.page-about .about-node-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: .62em;
  width: 7px;
  height: 7px;
  border-radius: 50%;
  border: 1px solid var(--gold);
}

/* ---------- 03 分类体系 ---------- */
.page-about .about-tax-figure {
  margin: 0 0 clamp(24px, 4vw, 40px);
}
.page-about .about-taxonomy {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(14px, 2.2vw, 22px);
}
.page-about .about-tax-card {
  position: relative;
  padding: clamp(18px, 2.6vw, 26px);
  background: var(--bg-2);
  border: 1px solid var(--line-faint);
  border-top: 2px solid var(--gold-soft);
  border-radius: var(--r-lg);
  transition: border-top-color .25s ease, background .25s ease, transform .25s ease;
}
.page-about .about-tax-card:hover {
  border-top-color: var(--gold);
  background: var(--bg-3);
  transform: translateY(-3px);
}
.page-about .about-tax-num {
  position: absolute;
  top: 12px;
  right: 16px;
  font-family: var(--font-mono);
  font-size: 26px;
  font-weight: 500;
  letter-spacing: .06em;
  color: var(--line);
  transition: color .25s ease;
}
.page-about .about-tax-card:hover .about-tax-num {
  color: var(--gold);
}
.page-about .about-tax-title {
  margin: 0 0 8px;
  font-size: 17px;
  font-weight: 700;
  letter-spacing: .02em;
  color: var(--ink);
}
.page-about .about-tax-desc {
  margin: 0 0 14px;
  font-size: 13.5px;
  line-height: 1.7;
  color: var(--muted);
  max-width: 26em;
}
.page-about .about-tax-subs {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 7px;
  border-top: 1px dashed var(--line-faint);
  padding-top: 12px;
}
.page-about .about-tax-subs li {
  display: flex;
  align-items: baseline;
  gap: 10px;
  font-size: 13.5px;
  color: var(--ink);
  opacity: .82;
}
.page-about .about-tax-code {
  flex: none;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .06em;
  color: var(--muted);
  transition: color .25s ease;
}
.page-about .about-tax-card:hover .about-tax-code {
  color: var(--gold-hi);
}

/* ---------- 04 团队 ---------- */
.page-about .about-team {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(22px, 4vw, 48px);
}
.page-about .about-line {
  padding: 0 0 20px;
  margin-bottom: 20px;
  border-bottom: 1px dashed var(--line-faint);
}
.page-about .about-line:last-child {
  padding-bottom: 0;
  margin-bottom: 0;
  border-bottom: 0;
}
.page-about .about-line-title {
  display: flex;
  align-items: center;
  gap: 10px;
  margin: 0 0 8px;
  font-size: 17px;
  font-weight: 700;
  color: var(--ink);
}
.page-about .about-line-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--gold);
  box-shadow: 0 0 0 4px rgba(201, 162, 39, .16);
}
.page-about .about-line p {
  margin: 0;
  font-size: 15px;
  line-height: 1.85;
  color: var(--ink);
  opacity: .86;
  max-width: 38em;
}
.page-about .about-team-figure {
  margin: 0;
}

/* ---------- 05 覆盖 ---------- */
.page-about .about-stat-band {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  padding: 1px;
  background: var(--line-faint);
  border: 1px solid var(--line-faint);
  border-radius: var(--r);
  overflow: hidden;
}
.page-about .about-stat {
  background: var(--deep);
  padding: clamp(20px, 3vw, 30px);
}
.page-about .about-stat-num {
  display: block;
  font-family: var(--font-mono);
  font-weight: 500;
  font-size: clamp(28px, 5vw, 40px);
  letter-spacing: .04em;
  color: var(--gold-hi);
}
.page-about .about-stat-cap {
  display: block;
  margin-top: 10px;
  font-size: 15px;
  font-weight: 600;
  color: var(--ink);
}
.page-about .about-stat-note {
  display: block;
  margin-top: 8px;
  font-size: 13px;
  line-height: 1.7;
  color: var(--muted);
}

/* ---------- 06 更新节奏 ---------- */
.page-about .about-cadence {
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
  margin: 0;
  padding: 0;
  list-style: none;
}
.page-about .about-cadence-item {
  display: grid;
  gap: 8px;
  padding: clamp(16px, 2.4vw, 22px);
  border: 1px solid var(--line-faint);
  border-radius: var(--r-lg);
  background: linear-gradient(180deg, var(--bg-2), var(--bg));
}
.page-about .about-cadence-key {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: .1em;
  color: var(--gold);
}
.page-about .about-cadence-item p {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--ink);
  opacity: .86;
}
.page-about .about-closing {
  margin: clamp(22px, 3.4vw, 34px) 0 0;
  padding-left: clamp(14px, 2vw, 20px);
  border-left: 2px solid var(--coral);
  font-size: 15px;
  line-height: 1.85;
  color: var(--ink);
  opacity: .9;
  max-width: 40em;
}

/* ---------- 末屏导流 ---------- */
.page-about .about-next {
  padding: clamp(44px, 7vw, 86px) 0;
  background:
    radial-gradient(90% 80% at 80% 100%, rgba(201, 162, 39, .10), transparent 60%),
    linear-gradient(180deg, var(--bg), var(--deep));
}
.page-about .about-next .section-head {
  border-left: 2px solid var(--gold);
  padding-left: clamp(14px, 2vw, 20px);
  margin-bottom: clamp(22px, 3.4vw, 34px);
}
.page-about .about-next .section-title {
  margin: 6px 0 6px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(21px, 3.2vw, 30px);
  letter-spacing: .02em;
  color: var(--ink);
}
.page-about .about-next-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(14px, 2.2vw, 20px);
}
.page-about .about-next-card {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: clamp(18px, 2.6vw, 24px);
  text-decoration: none;
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  background: rgba(16, 49, 42, .72);
  transition: border-color .25s ease, background .25s ease, transform .25s ease;
}
.page-about .about-next-card:hover {
  border-color: var(--gold);
  background: var(--bg-3);
  transform: translateY(-3px);
}
.page-about .about-next-num {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .16em;
  color: var(--gold);
}
.page-about .about-next-title {
  font-size: 17px;
  font-weight: 700;
  color: var(--ink);
}
.page-about .about-next-desc {
  font-size: 13.5px;
  line-height: 1.7;
  color: var(--muted);
}

/* ---------- 响应式 ---------- */
@media (min-width: 700px) {
  .page-about .toc-list {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
  .page-about .about-taxonomy {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  .page-about .about-stat-band {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
  .page-about .about-cadence {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  .page-about .about-next-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 880px) {
  .page-about .about-hero-grid {
    grid-template-columns: minmax(0, 1.45fr) minmax(0, 1fr);
    align-items: start;
  }
  .page-about .about-two-col {
    grid-template-columns: minmax(0, 1.55fr) minmax(0, 1fr);
    gap: clamp(30px, 4vw, 56px);
  }
  .page-about .about-timeline {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    gap: clamp(20px, 3vw, 36px);
  }
  .page-about .about-rail {
    flex-direction: column;
    overflow: visible;
    position: sticky;
    top: 108px;
    align-self: start;
  }
  .page-about .about-rail-item {
    text-align: center;
  }
  .page-about .about-track {
    border-left: 1px solid var(--line-faint);
    padding-left: clamp(20px, 3vw, 34px);
  }
  .page-about .about-team {
    grid-template-columns: minmax(0, 1fr) minmax(0, 380px);
    align-items: start;
  }
}

@media (min-width: 1080px) {
  .page-about .about-taxonomy {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
  .page-about .about-next-grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
  .page-about .about-cadence {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-tax-card,
  .page-about .about-next-card,
  .page-about .about-node {
    transition: none;
  }
  .page-about .about-tax-card:hover,
  .page-about .about-next-card:hover {
    transform: none;
  }
}