.page-about {
  --rail-w: 218px;
  --sec-space: clamp(38px, 5.5vw, 64px);
  background: var(--ink);
}

/* 首屏 */
.page-about .about-hero {
  padding: clamp(22px, 4vw, 44px) 0 clamp(26px, 4vw, 42px);
}

.page-about .about-hero h1 {
  font-family: var(--font-display);
  font-size: clamp(32px, 5.6vw, 62px);
  line-height: 1.06;
  letter-spacing: 0.045em;
  color: var(--text);
  margin: 10px 0 18px;
}

.page-about .about-lede {
  font-size: 17px;
  line-height: 1.8;
  color: var(--muted);
  max-width: 56ch;
  margin: 0;
}

.page-about .about-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 28px 0 0;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
}

.page-about .about-stats .stat {
  background: var(--ink-panel);
  padding: 14px 16px 16px;
}

.page-about .about-stats dt {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--muted);
  margin: 0 0 9px;
}

.page-about .about-stats dd {
  margin: 0;
  display: flex;
  align-items: baseline;
  gap: 6px;
  flex-wrap: wrap;
}

.page-about .stat-num {
  font-family: var(--font-display);
  font-size: clamp(26px, 3.4vw, 36px);
  line-height: 1;
  letter-spacing: 0.03em;
  color: var(--cyan);
}

.page-about .stat-unit {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--muted);
}

/* 主体栅格 */
.page-about .about-layout {
  padding: 0 0 clamp(48px, 8vw, 96px);
}

.page-about .about-rail {
  display: none;
}

.page-about .about-sec {
  padding: var(--sec-space) 0;
  border-top: 1px solid var(--line-soft);
  scroll-margin-top: 88px;
}

.page-about .about-sec:first-child {
  border-top: 0;
  padding-top: 10px;
}

.page-about .section-head {
  display: flex;
  align-items: baseline;
  gap: 12px;
  flex-wrap: wrap;
}

.page-about .section-title {
  font-family: var(--font-display);
  font-size: clamp(23px, 3.1vw, 34px);
  letter-spacing: 0.05em;
  line-height: 1.2;
  margin: 0;
  color: var(--text);
}

.page-about .sec-lede {
  font-size: 16px;
  line-height: 1.78;
  color: var(--muted);
  max-width: 62ch;
  margin: 14px 0 0;
}

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

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

.page-about .about-figure--ring {
  margin-top: 20px;
  max-width: 300px;
}

/* 时间线 */
.page-about .about-timeline {
  list-style: none;
  margin: 30px 0 0;
  padding: 0;
  position: relative;
}

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  left: 7px;
  top: 8px;
  bottom: 8px;
  width: 2px;
  background: linear-gradient(180deg, var(--cyan), var(--orange) 58%, var(--cyan-soft));
  opacity: 0.45;
}

.page-about .tl-node {
  position: relative;
  padding-left: 36px;
  margin-bottom: 30px;
}

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

.page-about .tl-dot {
  position: absolute;
  left: 0;
  top: 5px;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--ink);
  border: 2px solid var(--cyan);
  box-shadow: 0 0 0 4px rgba(47, 224, 192, 0.12);
}

.page-about .tl-node--orange .tl-dot {
  border-color: var(--orange);
  box-shadow: 0 0 0 4px rgba(255, 106, 43, 0.14);
}

.page-about .tl-kicker {
  font-size: 11px;
  letter-spacing: 0.12em;
  color: var(--muted);
  margin: 0 0 6px;
}

.page-about .tl-node--orange .tl-kicker {
  color: var(--orange);
}

.page-about .tl-title {
  font-family: var(--font-display);
  font-size: 20px;
  letter-spacing: 0.04em;
  line-height: 1.3;
  color: var(--text);
  margin: 0 0 8px;
}

.page-about .tl-desc {
  font-size: 16px;
  line-height: 1.78;
  color: var(--muted);
  margin: 0 0 12px;
  max-width: 60ch;
}

/* 展开控件 */
.page-about .expand-trigger {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--cyan);
  background: transparent;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 6px 12px;
  cursor: pointer;
  transition: border-color 0.16s var(--ease), color 0.16s var(--ease), background 0.16s var(--ease);
}

.page-about .expand-trigger:hover,
.page-about .expand-trigger:focus-visible {
  border-color: var(--cyan);
  color: var(--cyan-soft);
}

.page-about .expand-trigger[aria-expanded="true"] {
  background: rgba(47, 224, 192, 0.1);
  border-color: var(--cyan);
}

.page-about .expand-panel {
  display: none;
  margin-top: 12px;
}

.page-about .expand-panel.is-open {
  display: block;
}

.page-about .expand-panel ul {
  list-style: none;
  margin: 0;
  padding: 12px 16px;
  border-left: 2px solid var(--cyan);
  background: var(--ink-panel);
  border-radius: 0 var(--radius) var(--radius) 0;
}

.page-about .expand-panel li {
  position: relative;
  padding-left: 14px;
  font-size: 14px;
  line-height: 1.75;
  color: var(--muted);
  margin: 0 0 4px;
}

.page-about .expand-panel li:last-child {
  margin-bottom: 0;
}

.page-about .expand-panel li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.75em;
  width: 6px;
  height: 1px;
  background: var(--cyan);
}

/* 巡检留档便签 */
.page-about .about-note {
  margin-top: 32px;
  max-width: 520px;
  padding: 20px 22px;
}

.page-about .about-note .note-title {
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--muted-deep);
  margin: 0 0 10px;
}

.page-about .about-note .note-list {
  margin: 0;
  padding-left: 18px;
  font-size: 14px;
  line-height: 1.85;
  color: #24343F;
}

/* 团队 */
.page-about .team-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 12px;
  margin-top: 26px;
}

.page-about .team-card {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--ink-panel);
  padding: 18px 18px 16px;
  border-top: 2px solid var(--cyan);
}

.page-about .team-tag {
  display: inline-block;
  font-size: 11px;
  letter-spacing: 0.12em;
  color: var(--cyan);
  border: 1px solid var(--line);
  padding: 2px 8px;
  margin-bottom: 10px;
}

.page-about .team-title {
  font-family: var(--font-display);
  font-size: 19px;
  letter-spacing: 0.04em;
  color: var(--text);
  margin: 0 0 8px;
}

.page-about .team-desc {
  font-size: 15px;
  line-height: 1.75;
  color: var(--muted);
  margin: 0 0 12px;
}

.page-about .team-rot {
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--orange);
  margin: 0;
}

.page-about .team-foot {
  font-size: 15px;
  line-height: 1.78;
  color: var(--muted);
  margin: 20px 0 0;
}

/* 版本历程 */
.page-about .version-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--line-soft);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
}

.page-about .version-item {
  display: grid;
  gap: 6px;
  padding: 16px 18px;
  background: var(--ink);
}

.page-about .version-item:nth-child(odd) {
  background: var(--ink-panel);
}

.page-about .v-time {
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--orange);
}

.page-about .v-title {
  font-family: var(--font-display);
  font-size: 18px;
  letter-spacing: 0.04em;
  color: var(--text);
  margin: 0 0 6px;
}

.page-about .v-desc {
  font-size: 15px;
  line-height: 1.75;
  color: var(--muted);
  margin: 0;
}

.page-about .history-foot {
  font-size: 15px;
  line-height: 1.78;
  color: var(--muted);
  margin: 22px 0 0;
}

/* 平板与桌面 */
@media (min-width: 700px) {
  .page-about .about-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .team-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 14px;
  }

  .page-about .version-item {
    grid-template-columns: 118px minmax(0, 1fr);
    gap: 20px;
    align-items: start;
    padding: 18px 20px;
  }

  .page-about .v-time {
    padding-top: 4px;
  }
}

@media (min-width: 900px) {
  .page-about .about-layout {
    display: grid;
    grid-template-columns: var(--rail-w) minmax(0, 1fr);
    gap: clamp(28px, 4vw, 58px);
    align-items: start;
  }

  .page-about .about-rail {
    display: block;
    position: sticky;
    top: 96px;
    padding-top: 18px;
  }

  .page-about .rail-label {
    font-size: 11px;
    letter-spacing: 0.16em;
    color: var(--muted);
    margin: 0 0 12px;
  }

  .page-about .about-rail .chapter-nav {
    display: grid;
    gap: 2px;
    border-left: 1px solid var(--line);
  }

  .page-about .about-rail .chapter-link {
    display: block;
    font-size: 14px;
    line-height: 1.5;
    padding: 8px 12px;
    color: var(--muted);
    text-decoration: none;
    border-left: 2px solid transparent;
    margin-left: -1px;
    transition: color 0.16s var(--ease), border-color 0.16s var(--ease);
  }

  .page-about .about-rail .chapter-link:hover,
  .page-about .about-rail .chapter-link:focus-visible {
    color: var(--text);
  }

  .page-about .about-rail .chapter-link[aria-current="true"] {
    color: var(--cyan);
    border-left-color: var(--cyan);
    background: rgba(47, 224, 192, 0.06);
  }

  .page-about .about-figure--ring {
    max-width: 100%;
  }
}

@media (min-width: 1080px) {
  .page-about .about-lede {
    font-size: 18px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .expand-trigger,
  .page-about .about-rail .chapter-link {
    transition: none;
  }
}
<<<PAGE_CSS_END>>>