.page-about {
  --about-year-col: 104px;
  --about-sticky-top: calc(var(--header-h) + 32px);
  --about-paper-line: rgba(10, 15, 44, 0.14);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding-top: clamp(20px, 4vw, 40px);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  top: -32%;
  right: -12%;
  width: min(600px, 78vw);
  height: min(600px, 78vw);
  background: radial-gradient(circle, rgba(47, 230, 200, 0.15), transparent 62%);
  pointer-events: none;
}

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

.page-about .about-hero h1 {
  margin: 14px 0 0;
  font-family: var(--font-head);
  font-weight: 900;
  font-size: clamp(30px, 7.4vw, 58px);
  line-height: 1.16;
  letter-spacing: -0.02em;
  color: var(--paper);
  max-width: 22ch;
}

.page-about .about-hero__hl {
  color: var(--cyan);
}

.page-about .about-hero__lead {
  margin-top: 20px;
  max-width: 62ch;
}

.page-about .about-stats {
  list-style: none;
  margin: clamp(28px, 5vw, 52px) 0 0;
  padding: 1px;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  overflow: hidden;
}

.page-about .about-stat {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 16px 18px;
  background: var(--ink-800);
  min-width: 0;
}

.page-about .about-stat:last-child {
  grid-column: 1 / -1;
}

.page-about .about-stat__num {
  font-family: var(--font-mono);
  font-size: clamp(20px, 3.4vw, 28px);
  font-weight: 600;
  line-height: 1.1;
  color: var(--cyan);
}

.page-about .about-stat__label {
  font-size: 13px;
  color: var(--muted);
  letter-spacing: 0.02em;
}

/* ---------- 区块标题 ---------- */
.page-about .about-head {
  max-width: 68ch;
  margin-bottom: clamp(26px, 4vw, 44px);
}

.page-about .about-head h2 {
  margin: 10px 0 0;
  font-family: var(--font-head);
  font-weight: 900;
  font-size: clamp(23px, 4.2vw, 38px);
  line-height: 1.22;
  letter-spacing: -0.02em;
  color: var(--paper);
}

.page-about .about-head__desc {
  margin-top: 14px;
  color: var(--muted);
  font-size: 15px;
  line-height: 1.75;
}

/* ---------- 时间线 ---------- */
.page-about .about-timeline {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(20px, 3vw, 34px);
}

.page-about .about-years {
  display: flex;
  gap: 8px;
  overflow-x: auto;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--line);
  scrollbar-width: thin;
}

.page-about .about-years::-webkit-scrollbar {
  height: 4px;
}

.page-about .about-years::-webkit-scrollbar-thumb {
  background: var(--line);
  border-radius: 999px;
}

.page-about .about-year-link {
  flex: 0 0 auto;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.06em;
  color: var(--muted);
  text-decoration: none;
  padding: 7px 14px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: var(--ink-800);
  white-space: nowrap;
  transition: color 0.18s var(--ease), background 0.18s var(--ease), border-color 0.18s var(--ease);
}

.page-about .about-year-link:hover {
  color: var(--paper);
  border-color: var(--line-cyan);
}

.page-about .about-year-link.is-current {
  color: var(--ink-900);
  background: var(--cyan);
  border-color: var(--cyan);
}

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

.page-about .about-node {
  padding: 18px 0 26px;
  border-top: 1px solid var(--line-soft);
  scroll-margin-top: var(--about-sticky-top);
}

.page-about .about-node:first-child {
  border-top: 0;
  padding-top: 0;
}

.page-about .about-node__head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 10px 14px;
}

.page-about .about-node h3 {
  margin: 0;
  font-family: var(--font-head);
  font-weight: 700;
  font-size: clamp(18px, 2.6vw, 22px);
  line-height: 1.4;
  color: var(--paper);
}

.page-about .about-node > p {
  margin: 12px 0 0;
  max-width: 64ch;
  color: var(--muted);
  font-size: 15px;
  line-height: 1.75;
}

.page-about .about-node p a,
.page-about .about-more p a,
.page-about .about-deal p a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid var(--line-cyan);
}

.page-about .about-node p a:hover,
.page-about .about-more p a:hover,
.page-about .about-deal p a:hover {
  border-bottom-color: var(--cyan);
}

/* ---------- 折叠 ---------- */
.page-about .about-more {
  margin-top: 14px;
  padding-left: 14px;
  border-left: 2px solid var(--line-cyan);
  max-width: 64ch;
}

.page-about .about-more summary {
  list-style: none;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 14px;
  color: var(--cyan);
  padding: 4px 0;
}

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

.page-about .about-more summary::before {
  content: "＋";
  font-family: var(--font-mono);
  font-size: 12px;
}

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

.page-about .about-more p {
  margin: 8px 0 2px;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.75;
}

/* ---------- 图片 ---------- */
.page-about .about-figure {
  margin: clamp(32px, 5vw, 60px) 0 0;
}

.page-about .about-team-figure {
  margin: 0 0 clamp(26px, 4vw, 42px);
}

.page-about .about-flow-figure {
  margin: 0;
}

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

.page-about .figure__caption {
  margin-top: 12px;
  font-size: 13px;
  color: var(--muted);
  line-height: 1.7;
  max-width: 72ch;
}

/* ---------- 团队 ---------- */
.page-about .about-teams {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--gap);
}

.page-about .about-team {
  background: var(--ink-800);
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  padding: clamp(18px, 3vw, 26px);
  min-width: 0;
}

.page-about .about-team__count {
  margin: 0;
  font-family: var(--font-mono);
  font-size: clamp(30px, 5vw, 42px);
  font-weight: 600;
  line-height: 1;
  color: var(--cyan);
}

.page-about .about-team h3 {
  margin: 12px 0 0;
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 18px;
  color: var(--paper);
}

.page-about .about-team > p {
  margin: 10px 0 0;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.75;
}

.page-about .about-team .about-more {
  border-left-color: var(--line);
}

/* ---------- 流程 ---------- */
.page-about .about-flow {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(26px, 4vw, 44px);
}

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

.page-about .about-step {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 16px;
  padding: 18px 0;
  border-top: 1px solid var(--line-soft);
}

.page-about .about-step:first-child {
  border-top: 0;
  padding-top: 0;
}

.page-about .about-step__no {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.06em;
  color: var(--cyan);
  padding-top: 3px;
}

.page-about .about-step h3 {
  margin: 0;
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 17px;
  color: var(--paper);
}

.page-about .about-step p {
  margin: 8px 0 0;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.75;
  max-width: 58ch;
}

/* ---------- 资质（浅色分区） ---------- */
.page-about .about-credits-section .about-head h2 {
  color: var(--ink-900);
}

.page-about .about-credits-section .about-head__desc {
  color: #3D4778;
}

.page-about .about-credits-section .eyebrow {
  color: #4A5590;
}

.page-about .about-credits {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 0;
}

.page-about .about-credit {
  padding: 20px 0;
  border-top: 1px solid var(--about-paper-line);
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 6px;
}

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

.page-about .about-credit__num {
  font-family: var(--font-mono);
  font-size: clamp(24px, 4vw, 34px);
  font-weight: 600;
  line-height: 1.1;
  color: var(--ink-900);
  word-break: break-all;
}

.page-about .about-credit h3 {
  margin: 0;
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 16px;
  color: var(--ink-900);
}

.page-about .about-credit p {
  margin: 0;
  font-size: 14px;
  line-height: 1.7;
  color: #3D4778;
}

/* ---------- 合作 ---------- */
.page-about .about-partners {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  overflow: hidden;
}

.page-about .about-partner {
  background: var(--ink-800);
  padding: 20px;
  display: flex;
  align-items: baseline;
  gap: 14px;
  flex-wrap: wrap;
}

.page-about .about-partner__num {
  font-family: var(--font-mono);
  font-size: clamp(26px, 4vw, 36px);
  font-weight: 600;
  line-height: 1;
  color: var(--cyan);
}

.page-about .about-partner__label {
  font-size: 14px;
  color: var(--muted);
}

.page-about .about-deals {
  margin-top: clamp(24px, 4vw, 40px);
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--gap);
}

.page-about .about-deal {
  border-left: 2px solid var(--line-cyan);
  padding-left: 18px;
}

.page-about .about-deal h3 {
  margin: 0;
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 18px;
  color: var(--paper);
}

.page-about .about-deal p {
  margin: 10px 0 0;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.75;
  max-width: 56ch;
}

.page-about .about-reach {
  margin: clamp(24px, 4vw, 40px) 0 0;
  padding-top: 18px;
  border-top: 1px solid var(--line);
  font-family: var(--font-mono);
  font-size: 13px;
  line-height: 1.8;
  color: var(--muted);
  max-width: 68ch;
}

/* ---------- 结尾 ---------- */
.page-about .about-cta__panel {
  padding: clamp(24px, 4vw, 44px);
  background:
    linear-gradient(160deg, rgba(47, 230, 200, 0.12), transparent 58%),
    var(--ink-800);
}

.page-about .about-cta__panel h2 {
  margin: 10px 0 0;
  font-family: var(--font-head);
  font-weight: 900;
  font-size: clamp(23px, 4.2vw, 36px);
  line-height: 1.22;
  letter-spacing: -0.02em;
  color: var(--paper);
}

.page-about .about-cta__panel p {
  margin: 14px 0 0;
  max-width: 62ch;
  color: var(--muted);
  font-size: 15px;
  line-height: 1.75;
}

.page-about .about-cta__actions {
  margin-top: 24px;
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.page-about .about-cta__note {
  margin-top: 20px;
  padding-top: 16px;
  border-top: 1px solid var(--line);
  font-size: 13px;
  color: var(--muted);
}

/* ---------- 平板 ---------- */
@media (min-width: 700px) {
  .page-about .about-stats {
    grid-template-columns: repeat(5, minmax(0, 1fr));
  }

  .page-about .about-stat:last-child {
    grid-column: auto;
  }

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

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

  .page-about .about-credits {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 0 clamp(20px, 3vw, 36px);
  }

  .page-about .about-credit {
    border-top: 1px solid var(--about-paper-line);
  }
}

/* ---------- 桌面 ---------- */
@media (min-width: 900px) {
  .page-about .about-timeline {
    grid-template-columns: var(--about-year-col) minmax(0, 1fr);
    gap: clamp(28px, 5vw, 72px);
  }

  .page-about .about-years {
    flex-direction: column;
    align-items: stretch;
    overflow: visible;
    gap: 2px;
    padding: 0 0 0 0;
    border-bottom: 0;
    border-left: 1px solid var(--line);
    position: sticky;
    top: var(--about-sticky-top);
    align-self: start;
    max-height: calc(100vh - var(--about-sticky-top) - 32px);
  }

  .page-about .about-year-link {
    background: transparent;
    border: 0;
    border-radius: 0;
    padding: 9px 0 9px 18px;
    position: relative;
    font-size: 14px;
    text-align: left;
  }

  .page-about .about-year-link::before {
    content: "";
    position: absolute;
    left: -1px;
    top: 50%;
    width: 8px;
    height: 1px;
    background: var(--line);
    transform: translateY(-50%);
    transition: width 0.18s var(--ease), background 0.18s var(--ease), height 0.18s var(--ease);
  }

  .page-about .about-year-link:hover {
    background: transparent;
    color: var(--paper);
  }

  .page-about .about-year-link:hover::before {
    width: 14px;
    background: var(--line-cyan);
  }

  .page-about .about-year-link.is-current {
    background: transparent;
    color: var(--cyan);
  }

  .page-about .about-year-link.is-current::before {
    width: 20px;
    height: 2px;
    background: var(--cyan);
  }

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

  .page-about .about-team {
    grid-column: span 6;
  }

  .page-about .about-team:nth-child(1),
  .page-about .about-team:nth-child(4) {
    grid-column: span 7;
  }

  .page-about .about-team:nth-child(2),
  .page-about .about-team:nth-child(3) {
    grid-column: span 5;
  }

  .page-about .about-flow {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, 0.85fr);
    align-items: start;
  }

  .page-about .about-flow-figure {
    position: sticky;
    top: var(--about-sticky-top);
  }
}

@media (min-width: 1100px) {
  .page-about .about-hero h1 {
    max-width: 18ch;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-year-link,
  .page-about .about-year-link::before {
    transition: none;
  }
}