.page-about {
  --about-rail: 188px;
  --about-ink: #C6D4E8;
  --about-gap: clamp(26px, 4vw, 64px);
  padding-bottom: clamp(48px, 8vw, 96px);
  background: linear-gradient(180deg, rgba(13, 22, 36, 0.82) 0, rgba(6, 10, 18, 0) 460px);
  color: var(--paper);
}

.page-about img {
  max-width: 100%;
  height: auto;
  display: block;
}

.page-about figure {
  margin: clamp(18px, 3vw, 30px) 0;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  padding: clamp(26px, 6vw, 60px) 0 clamp(28px, 5vw, 52px);
  border-bottom: 1px solid var(--line);
  overflow: hidden;
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  right: -6%;
  bottom: 0;
  width: 46%;
  height: 2px;
  background: linear-gradient(90deg, rgba(49, 242, 223, 0), var(--cyan));
  transform: skewX(-8deg);
  opacity: 0.75;
}

.page-about .about-hero__tag {
  margin: clamp(14px, 2.4vw, 22px) 0 12px;
}

.page-about .about-hero h1 {
  margin: 0;
  font-size: clamp(32px, 7vw, 60px);
  line-height: 1.06;
  font-weight: 900;
  letter-spacing: -0.015em;
  color: var(--paper);
  max-width: 20ch;
}

.page-about .about-hero__lead {
  margin: clamp(16px, 2.6vw, 24px) 0 0;
  max-width: 62ch;
  font-size: clamp(15px, 2.1vw, 17px);
  line-height: 1.7;
  color: var(--about-ink);
}

.page-about .hero-facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px 18px;
  margin: clamp(24px, 4vw, 38px) 0 0;
}

.page-about .hero-facts > div {
  border-left: 1px solid var(--line-cyan);
  padding-left: 12px;
}

.page-about .hero-facts dt {
  margin: 0;
  font-size: 11px;
  letter-spacing: 0.12em;
  color: var(--mist);
}

.page-about .hero-facts dd {
  margin: 6px 0 0;
  font-size: clamp(16px, 2.4vw, 20px);
  font-weight: 700;
  color: var(--paper);
  font-variant-numeric: tabular-nums;
}

.page-about .hero-facts .mono {
  color: var(--cyan);
  font-size: 1.08em;
}

/* ---------- 主体栅格 ---------- */
.page-about .about-body {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--about-gap);
  padding-top: clamp(22px, 4vw, 46px);
}

/* ---------- 章节索引 ---------- */
.page-about .year-rail {
  min-width: 0;
  border-top: 1px solid var(--line);
  padding-top: 12px;
}

.page-about .rail-title {
  margin: 0 0 10px;
  font-size: 11px;
  letter-spacing: 0.12em;
  color: var(--mist);
  text-transform: uppercase;
}

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

.page-about .rail-list li {
  flex: none;
}

.page-about .rail-link {
  display: flex;
  align-items: baseline;
  gap: 8px;
  min-height: 44px;
  padding: 11px 13px;
  border: 1px solid var(--line);
  background: rgba(24, 38, 58, 0.55);
  color: var(--mist);
  font-size: 13px;
  text-decoration: none;
  white-space: nowrap;
  transition: border-color var(--dur) var(--ease), color var(--dur) var(--ease),
    background-color var(--dur) var(--ease);
}

.page-about .rail-link .num {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--cyan);
}

.page-about .rail-link:hover,
.page-about .rail-link:focus-visible {
  border-color: var(--line-cyan);
  background: rgba(49, 242, 223, 0.08);
  color: var(--paper);
}

.page-about .rail-link:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 2px;
}

.page-about .rail-note {
  margin: 10px 0 0;
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--steel);
}

/* ---------- 章节 ---------- */
.page-about .about-chapters {
  min-width: 0;
  display: grid;
  gap: clamp(32px, 5vw, 64px);
}

.page-about .chapter {
  scroll-margin-top: calc(var(--header-h) + 20px);
  border-top: 1px solid var(--line-strong);
  padding-top: clamp(20px, 3vw, 32px);
}

.page-about .chapter-head {
  display: flex;
  align-items: flex-start;
  gap: clamp(12px, 2vw, 22px);
  margin-bottom: clamp(16px, 2.6vw, 26px);
}

.page-about .chapter-num {
  flex: none;
  font-family: var(--font-mono);
  font-size: clamp(36px, 7vw, 64px);
  line-height: 0.86;
  letter-spacing: -0.05em;
  color: var(--steel);
}

.page-about .chapter-head__text {
  min-width: 0;
}

.page-about .chapter-head__text .tag {
  display: inline-block;
  margin: 0 0 10px;
}

.page-about .chapter h2 {
  margin: 0;
  font-size: clamp(21px, 3.4vw, 32px);
  line-height: 1.22;
  font-weight: 900;
  letter-spacing: -0.01em;
  color: var(--paper);
}

.page-about .chapter p {
  margin: 0 0 14px;
  max-width: 68ch;
  font-size: clamp(15px, 2vw, 16px);
  line-height: 1.7;
  color: var(--about-ink);
}

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

.page-about .chapter-links {
  margin-top: clamp(16px, 2.4vw, 22px) !important;
  padding-left: 14px;
  border-left: 2px solid var(--line-cyan);
  font-size: 15px !important;
}

.page-about .chapter a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(49, 242, 223, 0.45);
  padding-bottom: 1px;
}

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

/* ---------- 图 ---------- */
.page-about .chapter-figure .media-caption {
  margin-top: 10px;
  font-size: 12px;
  line-height: 1.6;
  color: var(--mist);
}

/* ---------- 流程步骤 ---------- */
.page-about .step-stack {
  display: grid;
  gap: 12px;
  margin-top: clamp(18px, 3vw, 26px);
}

.page-about .step {
  border: 1px solid var(--line);
  background: linear-gradient(180deg, rgba(24, 38, 58, 0.62), rgba(13, 22, 36, 0.92));
  box-shadow: 4px 4px 0 rgba(2, 4, 10, 0.55);
}

.page-about .step summary {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 6px 12px;
  min-height: 44px;
  padding: 14px 16px;
  cursor: pointer;
  list-style: none;
  color: var(--paper);
  font-weight: 700;
  font-size: 15px;
  line-height: 1.4;
}

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

.page-about .step summary:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: -2px;
}

.page-about .step-idx {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--amber);
}

.page-about .step[open] summary {
  border-bottom: 1px solid var(--line);
}

.page-about .step-body {
  padding: 14px 16px 16px;
  font-size: 15px;
  line-height: 1.7;
  color: var(--about-ink);
}

/* ---------- 团队 ---------- */
.page-about .team-grid {
  display: grid;
  gap: 14px;
  margin: clamp(18px, 3vw, 26px) 0 0;
}

.page-about .team-card {
  padding: 18px 18px 16px;
}

.page-about .team-count {
  margin: 0;
  font-size: clamp(28px, 5vw, 38px);
  line-height: 1;
  color: var(--cyan);
  letter-spacing: -0.02em;
}

.page-about .team-card h3 {
  margin: 10px 0 8px;
  font-size: 16px;
  font-weight: 700;
  color: var(--paper);
}

.page-about .team-card p {
  margin: 0;
  font-size: 14px;
  line-height: 1.65;
  color: var(--about-ink);
}

/* ---------- 节奏 ---------- */
.page-about .cadence-svg {
  display: block;
  width: 100%;
  height: auto;
  margin: clamp(18px, 3vw, 26px) 0 clamp(14px, 2vw, 18px);
  padding: 10px 0;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.page-about .cadence-svg text {
  font-family: var(--font-mono);
}

.page-about .cadence-list {
  display: grid;
  gap: 12px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .cadence-list li {
  display: grid;
  gap: 6px;
  padding: 12px 14px;
  border-left: 2px solid var(--line-amber);
  background: rgba(13, 22, 36, 0.72);
}

.page-about .cadence-key {
  font-size: 13px;
  letter-spacing: 0.08em;
  color: var(--amber);
}

.page-about .cadence-val {
  font-size: 14.5px;
  line-height: 1.7;
  color: var(--about-ink);
}

/* ---------- 合作 ---------- */
.page-about .partner-grid {
  display: grid;
  gap: 12px;
  margin: clamp(18px, 3vw, 26px) 0 0;
}

.page-about .partner-card {
  padding: 16px 16px 14px;
  border-left: 2px solid var(--line-magenta);
}

.page-about .partner-card h3 {
  margin: 0 0 8px;
  font-size: 15px;
  font-weight: 700;
  color: var(--paper);
}

.page-about .partner-card p {
  margin: 0;
  font-size: 14px;
  line-height: 1.65;
  color: var(--about-ink);
}

.page-about .tag-wall {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: clamp(18px, 3vw, 26px) 0 0;
}

/* ---------- 历程 ---------- */
.page-about .history {
  list-style: none;
  margin: clamp(18px, 3vw, 26px) 0 0;
  padding: 0;
}

.page-about .history li {
  position: relative;
  padding: 0 0 22px 26px;
  border-left: 1px solid var(--line-amber);
}

.page-about .history li::before {
  content: "";
  position: absolute;
  left: -5px;
  top: 8px;
  width: 9px;
  height: 9px;
  background: var(--amber);
  border-radius: 50%;
}

.page-about .history li:last-child {
  padding-bottom: 0;
  border-left-color: transparent;
}

.page-about .history-year {
  margin: 0 0 4px;
  font-size: 14px;
  letter-spacing: 0.1em;
  color: var(--amber);
}

.page-about .history-text {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.7;
  color: var(--about-ink);
}

/* ---------- 站点信息 ---------- */
.page-about .site-facts {
  margin-top: clamp(20px, 3vw, 30px);
  padding: clamp(16px, 3vw, 24px);
  border: 1px solid var(--line);
  background: rgba(24, 38, 58, 0.42);
}

.page-about .site-facts h3 {
  margin: 0 0 14px;
  font-size: 13px;
  letter-spacing: 0.12em;
  color: var(--mist);
  font-weight: 500;
}

.page-about .fact-list {
  display: grid;
  gap: 10px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .fact-list li {
  display: grid;
  gap: 2px;
  padding-bottom: 10px;
  border-bottom: 1px dashed var(--line);
}

.page-about .fact-list li:last-child {
  padding-bottom: 0;
  border-bottom: 0;
}

.page-about .fact-key {
  font-size: 11px;
  letter-spacing: 0.12em;
  color: var(--mist);
}

.page-about .fact-val {
  font-size: 14.5px;
  line-height: 1.6;
  color: var(--paper);
  word-break: break-word;
}

/* ---------- 收尾 ---------- */
.page-about .about-cta {
  margin-top: clamp(8px, 2vw, 16px);
}

.page-about .cta-card {
  padding: clamp(20px, 4vw, 34px);
  border-top: 2px solid var(--cyan);
}

.page-about .cta-card h2 {
  margin: 0 0 12px;
  font-size: clamp(20px, 3.2vw, 28px);
  line-height: 1.25;
  font-weight: 900;
  color: var(--paper);
}

.page-about .cta-card p {
  margin: 0 0 20px;
  max-width: 62ch;
  font-size: 15px;
  line-height: 1.7;
  color: var(--about-ink);
}

.page-about .cta-card a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(49, 242, 223, 0.45);
}

.page-about .cta-card a:hover,
.page-about .cta-card a:focus-visible {
  color: var(--paper);
  border-bottom-color: var(--cyan);
}

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

.page-about .cta-actions .btn {
  text-decoration: none;
  border-bottom: 0;
}

@media (min-width: 720px) {
  .page-about .hero-facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .team-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 12px;
  }

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

  .page-about .cadence-list li {
    grid-template-columns: 96px minmax(0, 1fr);
    align-items: baseline;
    gap: 14px;
  }

  .page-about .fact-list li {
    grid-template-columns: 96px minmax(0, 1fr);
    align-items: baseline;
    gap: 12px;
  }
}

@media (min-width: 1024px) {
  .page-about .about-body {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    align-items: start;
  }

  .page-about .year-rail {
    position: sticky;
    top: calc(var(--header-h) + 24px);
    border-top: 0;
    border-left: 1px solid var(--line);
    padding: 4px 0 4px 14px;
  }

  .page-about .rail-list {
    flex-direction: column;
    gap: 6px;
    overflow: visible;
    padding-bottom: 0;
  }

  .page-about .rail-link {
    border-color: transparent;
    background: transparent;
    padding: 9px 10px;
  }

  .page-about .rail-link:hover,
  .page-about .rail-link:focus-visible {
    border-color: var(--line-cyan);
    background: rgba(49, 242, 223, 0.07);
  }

  .page-about .chapter-num {
    margin-top: 2px;
  }

  .page-about .about-chapters {
    padding-left: clamp(8px, 2vw, 24px);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .rail-link {
    transition: none;
  }
}
<<<END>>>