.page-about {
  --about-rail: 168px;
}

.page-about .breadcrumb {
  font-family: var(--font-data);
  font-size: 12px;
  letter-spacing: .06em;
  color: var(--mute);
  padding: clamp(14px, 2.4vw, 22px) 0 0;
}

.page-about .breadcrumb a {
  color: var(--mute);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color .18s var(--ease), border-color .18s var(--ease);
}

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

.page-about .breadcrumb span[aria-hidden] {
  margin: 0 6px;
  color: rgba(126, 154, 146, .6);
}

/* ---------- 首屏框景 ---------- */
.page-about .about-hero {
  padding: clamp(16px, 2.6vw, 28px) 0 clamp(26px, 4vw, 44px);
}

.page-about .about-hero > .container {
  position: relative;
  padding: clamp(22px, 4vw, 48px);
  border: 1px solid var(--line-soft);
  background:
    radial-gradient(120% 90% at 100% 0%, rgba(51, 241, 207, .10), transparent 58%),
    var(--ink);
}

.page-about .about-hero > .container::before {
  content: "";
  position: absolute;
  top: 8px;
  left: 8px;
  right: 8px;
  height: 1px;
  background: repeating-linear-gradient(90deg, var(--line) 0 1px, transparent 1px 14px);
  pointer-events: none;
}

.page-about .eyebrow {
  margin: 0 0 14px;
  font-family: var(--font-data);
  font-size: 12px;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--cyan);
}

.page-about h1 {
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(30px, 5.4vw, 58px);
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: .02em;
  color: var(--warm);
  max-width: 18em;
}

.page-about .about-hero__lead {
  margin: 18px 0 0;
  max-width: 40em;
  font-size: clamp(15px, 1.7vw, 17px);
  line-height: 1.9;
  color: rgba(245, 242, 234, .82);
}

.page-about .about-figures {
  list-style: none;
  margin: clamp(22px, 3.4vw, 34px) 0 0;
  padding: clamp(16px, 2.4vw, 22px) 0 0;
  border-top: 1px solid var(--line-soft);
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px 12px;
}

.page-about .about-figures li {
  display: grid;
  gap: 4px;
  min-width: 0;
}

.page-about .about-figures__num {
  font-family: var(--font-data);
  font-variant-numeric: tabular-nums;
  font-size: clamp(22px, 3.6vw, 32px);
  line-height: 1;
  letter-spacing: .02em;
  color: var(--cyan);
}

.page-about .about-figures li:nth-child(4) .about-figures__num {
  color: var(--amber);
}

.page-about .about-figures small {
  font-size: 11.5px;
  letter-spacing: .12em;
  color: var(--mute);
}

/* ---------- 双栏骨架 ---------- */
.page-about .about-frame {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(24px, 3.4vw, 40px);
  padding-top: clamp(18px, 2.6vw, 28px);
  padding-bottom: clamp(48px, 7vw, 88px);
}

.page-about .about-flow {
  display: grid;
  gap: clamp(52px, 8vw, 104px);
  min-width: 0;
}

/* ---------- 左侧刻度 ---------- */
.page-about .about-rail {
  display: grid;
  gap: 10px;
  padding-bottom: 14px;
  border-bottom: 1px solid var(--line-soft);
  min-width: 0;
}

.page-about .about-rail__label {
  margin: 0;
  font-family: var(--font-data);
  font-size: 11px;
  letter-spacing: .18em;
  color: var(--mute);
}

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

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

.page-about .about-rail__node {
  display: grid;
  gap: 2px;
  flex: 0 0 auto;
  padding: 7px 12px;
  border: 1px solid var(--line);
  text-decoration: none;
  transition: border-color .2s var(--ease), background .2s var(--ease);
}

.page-about .about-rail__year {
  font-family: var(--font-data);
  font-variant-numeric: tabular-nums;
  font-size: 14px;
  letter-spacing: .05em;
  color: var(--warm);
}

.page-about .about-rail__word {
  font-size: 11px;
  letter-spacing: .1em;
  color: var(--mute);
}

.page-about .about-rail__node:hover,
.page-about .about-rail__node:focus-visible {
  border-color: var(--cyan);
  background: rgba(51, 241, 207, .10);
}

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

.page-about .about-rail__foot {
  display: none;
  margin: 0;
  font-family: var(--font-data);
  font-size: 11px;
  letter-spacing: .1em;
  color: var(--mute);
}

/* ---------- 章节通用 ---------- */
.page-about .about-block__head {
  display: flex;
  align-items: baseline;
  gap: 14px;
  padding-bottom: 12px;
  margin-bottom: 20px;
  border-bottom: 1px solid var(--line-soft);
}

.page-about .about-block__index {
  flex: 0 0 auto;
  font-family: var(--font-data);
  font-size: 12px;
  letter-spacing: .14em;
  color: var(--cyan);
}

.page-about h2 {
  margin: 0;
  font-family: var(--font-heading);
  font-weight: 800;
  font-size: clamp(21px, 3vw, 32px);
  line-height: 1.38;
  letter-spacing: .05em;
  color: var(--warm);
}

.page-about .about-lead {
  margin: 0 0 22px;
  max-width: 44em;
  font-size: clamp(15px, 1.7vw, 16.5px);
  line-height: 1.95;
  color: rgba(245, 242, 234, .84);
}

.page-about p {
  margin: 0 0 14px;
  font-size: clamp(15px, 1.65vw, 16px);
  line-height: 1.92;
  color: rgba(245, 242, 234, .8);
}

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

.page-about a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid var(--line-strong);
  transition: color .18s var(--ease), border-color .18s var(--ease);
}

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

/* ---------- 01 服务对象 ---------- */
.page-about .about-audience {
  display: grid;
  gap: 0;
}

.page-about .about-audience__item {
  position: relative;
  padding: 20px 0 20px 24px;
  border-left: 1px solid var(--line-soft);
}

.page-about .about-audience__item::before {
  content: "";
  position: absolute;
  left: -4px;
  top: 26px;
  width: 7px;
  height: 7px;
  background: var(--cyan);
  border-radius: 50%;
}

.page-about .about-audience__item:nth-child(2)::before {
  background: var(--amber);
}

.page-about .about-audience__item:nth-child(3)::before {
  background: var(--blue);
}

.page-about .about-audience__item h3 {
  margin: 0 0 8px;
  font-family: var(--font-heading);
  font-size: 17px;
  font-weight: 700;
  letter-spacing: .06em;
  color: var(--warm);
}

/* ---------- 02 发展阶段 ---------- */
.page-about .about-eras {
  display: grid;
  gap: 14px;
}

.page-about .about-era {
  position: relative;
  display: grid;
  gap: 10px;
  padding: clamp(18px, 2.6vw, 26px);
  background: var(--ink-2);
  border: 1px solid var(--line-soft);
  border-left: 2px solid var(--line);
  scroll-margin-top: 140px;
  transition: border-color .2s var(--ease), background .2s var(--ease);
}

.page-about .about-era::after {
  content: "";
  position: absolute;
  right: 10px;
  bottom: 10px;
  width: 18px;
  height: 18px;
  border-right: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  pointer-events: none;
}

.page-about .about-era:hover,
.page-about .about-era:target {
  border-left-color: var(--cyan);
  background: rgba(51, 241, 207, .07);
}

.page-about .about-era__year {
  font-family: var(--font-data);
  font-variant-numeric: tabular-nums;
  font-size: 20px;
  letter-spacing: .08em;
  color: var(--cyan);
}

.page-about .about-era h3 {
  margin: 0;
  font-family: var(--font-heading);
  font-size: 17.5px;
  font-weight: 700;
  line-height: 1.5;
  letter-spacing: .05em;
  color: var(--warm);
}

.page-about .about-era p {
  margin: 0;
  font-size: 15px;
  line-height: 1.85;
}

/* ---------- 图片 ---------- */
.page-about .about-figure {
  margin: 24px 0 0;
}

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

.page-about .about-figure figcaption {
  margin-top: 10px;
  font-family: var(--font-data);
  font-size: 12px;
  letter-spacing: .04em;
  line-height: 1.7;
  color: var(--mute);
}

.page-about .about-figure--tall {
  max-width: 360px;
}

/* ---------- 03 球队库 ---------- */
.page-about .about-library {
  display: grid;
  gap: 24px;
}

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

.page-about .about-fields {
  list-style: none;
  margin: 16px 0 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.page-about .about-fields li {
  font-family: var(--font-data);
  font-size: 12px;
  letter-spacing: .04em;
  padding: 6px 10px;
  border: 1px solid var(--line);
  color: var(--paper);
}

.page-about .about-fields li:nth-child(2) {
  border-color: rgba(240, 169, 60, .55);
  color: var(--amber);
}

.page-about .about-fields li:nth-child(4) {
  border-color: rgba(76, 134, 255, .55);
  color: var(--blue);
}

.page-about .about-library__figure {
  margin: 0;
}

/* ---------- 04 额度 ---------- */
.page-about .about-quota {
  display: grid;
  gap: 20px;
  padding: clamp(22px, 4vw, 42px);
  background: var(--paper);
  border: 1px solid rgba(16, 18, 20, .14);
}

.page-about .about-quota__num {
  font-family: var(--font-data);
  font-variant-numeric: tabular-nums;
  font-size: clamp(56px, 13vw, 104px);
  line-height: .86;
  letter-spacing: -.02em;
  color: var(--carbon);
}

.page-about .about-quota__num small {
  display: block;
  margin-top: 12px;
  font-family: var(--font-heading);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: .14em;
  color: rgba(16, 18, 20, .62);
}

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

.page-about .about-quota h2 {
  color: var(--carbon);
  margin-bottom: 14px;
}

.page-about .about-quota p {
  color: rgba(16, 18, 20, .76);
}

/* ---------- 05 团队 ---------- */
.page-about .about-roles {
  display: grid;
  border-bottom: 1px solid var(--line-soft);
}

.page-about .about-role {
  border-top: 1px solid var(--line-soft);
  padding: 16px 0;
}

.page-about .about-role summary {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 14px;
  cursor: pointer;
  list-style: none;
  font-family: var(--font-heading);
  font-size: 15.5px;
  font-weight: 700;
  letter-spacing: .05em;
  color: var(--warm);
}

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

.page-about .about-role summary::after {
  content: "+";
  flex: 0 0 auto;
  font-family: var(--font-data);
  font-size: 18px;
  line-height: 1;
  color: var(--cyan);
}

.page-about .about-role[open] summary::after {
  content: "−";
}

.page-about .about-role[open] summary {
  color: var(--cyan);
}

.page-about .about-role p {
  margin: 10px 0 0;
  font-size: 15px;
  line-height: 1.85;
}

.page-about .about-note {
  margin: 20px 0 0;
  font-size: 14.5px;
  color: rgba(245, 242, 234, .7);
}

/* ---------- 收尾 ---------- */
.page-about .about-cta {
  display: grid;
  gap: 14px;
  padding: clamp(24px, 4vw, 44px);
  border: 1px solid var(--line-strong);
  background: linear-gradient(150deg, rgba(51, 241, 207, .10), rgba(10, 42, 36, 0) 68%);
}

.page-about .about-cta h2 {
  font-family: var(--font-display);
  letter-spacing: .03em;
}

.page-about .about-cta p {
  max-width: 40em;
}

.page-about .about-cta__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 6px;
}

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

/* ---------- 宽屏 ---------- */
@media (min-width: 760px) {
  .page-about .about-figures {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 18px;
  }

  .page-about .about-library {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, .95fr);
    align-items: start;
    gap: clamp(24px, 4vw, 44px);
  }

  .page-about .about-library__figure {
    margin-top: 4px;
  }

  .page-about .about-quota {
    grid-template-columns: auto minmax(0, 1fr);
    align-items: center;
    gap: clamp(24px, 4vw, 48px);
  }
}

@media (min-width: 960px) {
  .page-about .about-frame {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    gap: clamp(32px, 4.6vw, 68px);
  }

  .page-about .about-rail {
    position: sticky;
    top: 104px;
    align-self: start;
    display: block;
    padding-bottom: 0;
    border-bottom: 0;
  }

  .page-about .about-rail__label {
    margin-bottom: 16px;
  }

  .page-about .about-rail__list {
    display: grid;
    gap: 0;
    overflow: visible;
    position: relative;
    padding-left: 20px;
  }

  .page-about .about-rail__list::before {
    content: "";
    position: absolute;
    left: 4px;
    top: 10px;
    bottom: 10px;
    width: 1px;
    background: linear-gradient(180deg, var(--cyan), rgba(51, 241, 207, .08));
  }

  .page-about .about-rail__list li {
    position: relative;
    padding: 12px 0;
  }

  .page-about .about-rail__list li::before {
    content: "";
    position: absolute;
    left: -20px;
    top: 19px;
    width: 11px;
    height: 11px;
    border: 1px solid var(--line-strong);
    background: var(--ink);
  }

  .page-about .about-rail__list li:hover::before {
    background: var(--cyan);
    border-color: var(--cyan);
  }

  .page-about .about-rail__node {
    border: 0;
    padding: 0;
    background: none;
  }

  .page-about .about-rail__node:hover,
  .page-about .about-rail__node:focus-visible {
    background: none;
  }

  .page-about .about-rail__node:hover .about-rail__year,
  .page-about .about-rail__node:focus-visible .about-rail__year {
    color: var(--cyan);
  }

  .page-about .about-rail__foot {
    display: block;
    margin-top: 22px;
    padding-top: 14px;
    border-top: 1px solid var(--line-soft);
  }

  .page-about .about-era:hover,
  .page-about .about-era:target {
    transform: translateY(-2px);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-era,
  .page-about .about-rail__node,
  .page-about .about-role summary {
    transition: none;
  }

  .page-about .about-era:hover,
  .page-about .about-era:target {
    transform: none;
  }
}