.page-about {
  --about-note-w: 236px;
  --about-measure: 680px;
  padding-block: 26px 88px;
}

.page-about .about-shell {
  position: relative;
}

/* ---------- 面包屑 ---------- */
.page-about .breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--muted);
  padding-bottom: 18px;
}

.page-about .breadcrumb a {
  color: var(--muted);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color 0.24s ease, border-color 0.24s ease;
}

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

.page-about .breadcrumb .sep {
  color: var(--line-600);
}

/* ---------- 封面 ---------- */
.page-about .about-cover {
  padding: 34px 0 34px;
  border-top: 1px solid var(--line-600);
  border-bottom: 1px solid var(--line-600);
}

.page-about .about-kicker {
  margin: 0;
  color: var(--signal);
}

.page-about .about-title {
  font-family: var(--font-display);
  font-weight: 300;
  font-size: clamp(34px, 8.2vw, 72px);
  line-height: 1.06;
  letter-spacing: -0.012em;
  color: var(--text);
  margin: 14px 0 0;
  max-width: 12em;
}

.page-about .about-lede {
  margin: 22px 0 0;
  max-width: 46em;
  font-size: 16px;
  line-height: 1.8;
  color: var(--muted);
}

.page-about .about-facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 30px 0 0;
  padding: 0;
  background: var(--line-600);
  border: 1px solid var(--line-600);
}

.page-about .about-facts > div {
  background: var(--ink-900);
  padding: 14px 16px;
}

.page-about .about-facts dt {
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--muted);
}

.page-about .about-facts dd {
  margin: 7px 0 0;
  font-size: 16px;
  color: var(--path);
}

/* ---------- 章节索引条 ---------- */
.page-about .about-toc {
  position: sticky;
  top: var(--bar-h);
  z-index: 5;
  margin: 0 0 4px;
  padding: 10px 0 9px;
  background: rgba(10, 26, 47, 0.94);
  border-bottom: 1px solid var(--line-600);
}

.page-about .toc-label {
  margin: 0 0 8px;
  color: var(--muted);
}

.page-about .toc-list {
  display: flex;
  gap: 20px;
  margin: 0;
  padding: 0 0 2px;
  list-style: none;
  overflow-x: auto;
  scrollbar-width: none;
}

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

.page-about .toc-list a {
  display: inline-flex;
  align-items: baseline;
  gap: 6px;
  white-space: nowrap;
  font-size: 13px;
  color: var(--muted);
  text-decoration: none;
  padding: 2px 0 4px;
  border-bottom: 1px solid transparent;
  transition: color 0.24s ease, border-color 0.24s ease;
}

.page-about .toc-idx {
  font-size: 11px;
  color: var(--line-600);
  transition: color 0.24s ease;
}

.page-about .toc-list a:hover,
.page-about .toc-list a:focus-visible {
  color: var(--text);
}

.page-about .toc-list a[aria-current] {
  color: var(--path);
  border-bottom-color: var(--path);
}

.page-about .toc-list a[aria-current] .toc-idx {
  color: var(--path);
}

/* ---------- 章节骨架 ---------- */
.page-about .sec {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 22px;
  padding: 46px 0;
  border-bottom: 1px solid var(--line-600);
}

.page-about .sec-body {
  max-width: var(--about-measure);
}

.page-about .sec-num {
  display: flex;
  align-items: center;
  gap: 12px;
  margin: 0 0 16px;
  font-family: var(--font-mono);
  letter-spacing: 0.18em;
  color: var(--path);
}

.page-about .sec-num::after {
  content: "";
  flex: 1 1 auto;
  height: 1px;
  background: var(--line-600);
}

.page-about .sec h2 {
  font-family: var(--font-display);
  font-weight: 400;
  font-size: clamp(24px, 4.6vw, 38px);
  line-height: 1.2;
  letter-spacing: -0.008em;
  color: var(--text);
  margin: 0 0 20px;
  max-width: 20em;
}

.page-about .sec-body > p {
  margin: 0 0 16px;
  font-size: 16px;
  line-height: 1.85;
  color: var(--text);
}

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

.page-about .sec-note {
  align-self: start;
  padding-top: 12px;
  border-top: 1px solid var(--path);
  font-size: 13px;
  line-height: 1.8;
  color: var(--muted);
}

.page-about .sec-note p {
  margin: 0;
}

/* ---------- 图框 ---------- */
.page-about .about-figure {
  margin: 6px 0 26px;
  padding: 10px;
  background: var(--ink-800);
  border: 1px solid var(--line-600);
}

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

.page-about .about-figure--team {
  max-width: 520px;
  background: var(--paper);
  border-color: var(--paper);
}

.page-about .about-figure--team .media-frame__cap {
  color: var(--ink-800);
}

.page-about .about-figure .media-frame__cap {
  margin: 10px 0 0;
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--muted);
}

/* ---------- 时间线 ---------- */
.page-about .tl {
  position: relative;
  margin: 28px 0 0;
  padding: 0;
  list-style: none;
}

.page-about .tl::before {
  content: "";
  position: absolute;
  left: 7px;
  top: 8px;
  bottom: 10px;
  width: 1px;
  background: linear-gradient(180deg, var(--path), var(--signal-deep));
  opacity: 0.6;
}

.page-about .tl-node {
  position: relative;
  padding: 0 0 30px 34px;
  outline: none;
}

.page-about .tl-node:last-child {
  padding-bottom: 4px;
}

.page-about .tl-node::before {
  content: "";
  position: absolute;
  left: 0;
  top: 5px;
  width: 15px;
  height: 15px;
  border-radius: 50%;
  background: var(--ink-900);
  border: 1px solid var(--path);
  transition: background 0.24s ease, box-shadow 0.24s ease;
}

.page-about .tl-node:hover::before,
.page-about .tl-node:focus-visible::before,
.page-about .tl-node:focus::before {
  background: var(--path);
  box-shadow: 0 0 0 5px rgba(25, 224, 192, 0.16);
}

.page-about .tl-year {
  margin: 0;
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--signal);
}

.page-about .tl-title {
  margin: 6px 0 6px;
  font-size: 17px;
  font-weight: 500;
  color: var(--text);
}

.page-about .tl-text {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--muted);
}

.page-about .tl-more {
  max-height: 0;
  margin: 0;
  overflow: hidden;
  opacity: 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--muted);
  transition: max-height 0.3s ease, opacity 0.3s ease, margin-top 0.3s ease;
}

.page-about .tl-node:hover .tl-more,
.page-about .tl-node:focus .tl-more,
.page-about .tl-node:focus-within .tl-more {
  max-height: 9em;
  margin-top: 8px;
  opacity: 1;
}

/* ---------- 服务标准 ---------- */
.page-about .std-list {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  margin: 0 0 24px;
  padding: 0;
  list-style: none;
  background: var(--line-600);
  border: 1px solid var(--line-600);
}

.page-about .std-list li {
  background: var(--ink-900);
  padding: 16px 18px;
}

.page-about .std-k {
  margin: 0;
  font-size: 17px;
  color: var(--path);
}

.page-about .std-v {
  margin: 7px 0 0;
  font-size: 13px;
  line-height: 1.6;
  color: var(--muted);
}

.page-about .std-cta {
  margin-top: 24px;
}

/* ---------- 出口条 ---------- */
.page-about .about-exits {
  padding: 50px 0 6px;
}

.page-about .about-exits h2 {
  font-family: var(--font-display);
  font-weight: 400;
  font-size: clamp(22px, 4vw, 32px);
  line-height: 1.24;
  color: var(--text);
  margin: 12px 0 0;
  max-width: 22em;
}

.page-about .exit-list {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  margin: 26px 0 0;
  padding: 0;
  list-style: none;
  background: var(--line-600);
  border: 1px solid var(--line-600);
}

.page-about .exit-list a {
  display: flex;
  flex-direction: column;
  gap: 7px;
  padding: 20px 18px;
  background: var(--ink-900);
  text-decoration: none;
  transition: background 0.24s ease;
}

.page-about .exit-list a:hover,
.page-about .exit-list a:focus-visible {
  background: var(--ink-800);
}

.page-about .exit-name {
  font-size: 17px;
  font-weight: 500;
  color: var(--text);
  transition: color 0.24s ease;
}

.page-about .exit-list a:hover .exit-name,
.page-about .exit-list a:focus-visible .exit-name {
  color: var(--path);
}

.page-about .exit-desc {
  font-size: 13px;
  line-height: 1.65;
  color: var(--muted);
}

/* ---------- 断点 ---------- */
@media (min-width: 620px) {
  .page-about .about-facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

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

  .page-about .about-title {
    max-width: 13em;
  }
}

@media (min-width: 900px) {
  .page-about {
    padding-block: 34px 104px;
  }

  .page-about .sec {
    grid-template-columns: minmax(0, 1fr) var(--about-note-w);
    gap: 52px;
    padding: 56px 0;
  }

  .page-about .sec-note {
    position: sticky;
    top: calc(var(--bar-h) + 58px);
  }

  .page-about .about-cover {
    padding: 44px 0 40px;
  }

  .page-about .about-lede {
    font-size: 17px;
  }

  .page-about .about-figure--team {
    float: right;
    width: 46%;
    max-width: 340px;
    margin: 4px 0 18px 28px;
  }
}

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

  .page-about .sec-body > p {
    font-size: 17px;
  }
}
<<<END>>>