.page-about {
  --about-rail-w: 132px;
  --about-track: 28px;
}

/* ============ 右侧章节索引 ============ */
.page-about .about-rail {
  display: none;
}

@media (min-width: 1440px) {
  .page-about .about-rail {
    display: block;
    position: fixed;
    top: 50%;
    right: 20px;
    transform: translateY(-50%);
    width: var(--about-rail-w);
    z-index: 6;
    pointer-events: none;
  }

  .page-about .about-rail-list {
    list-style: none;
    margin: 0;
    padding: 0;
    display: flex;
    flex-direction: column;
    gap: 12px;
    text-align: right;
    pointer-events: auto;
  }

  .page-about .about-rail-link {
    display: block;
    font-family: var(--font-mono);
    font-size: 11px;
    line-height: 1.4;
    letter-spacing: 0.04em;
    color: var(--violet);
    text-decoration: none;
    padding: 4px 8px 4px 0;
    border-right: 1px solid transparent;
    transition: color 240ms var(--ease), border-color 240ms var(--ease);
  }

  .page-about .about-rail-link:hover,
  .page-about .about-rail-link:focus-visible {
    color: var(--cyan-soft);
    border-right-color: var(--line);
    outline: none;
  }

  .page-about .about-rail-link[aria-current="true"] {
    color: var(--amber);
    border-right-color: var(--amber);
  }
}

/* ============ 首屏 ============ */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding: 64px 0 80px;
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  top: 0;
  right: 0;
  width: 46%;
  height: 100%;
  background: linear-gradient(155deg, rgba(0, 229, 208, 0.10), rgba(11, 16, 38, 0) 64%);
  clip-path: polygon(24% 0, 100% 0, 100% 100%, 0 100%);
  pointer-events: none;
  z-index: 0;
}

.page-about .about-hero-grid {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: 1fr;
  gap: 40px;
  align-items: center;
}

.page-about .about-hero-copy .eyebrow {
  margin-bottom: 14px;
}

.page-about .about-hero-copy h1 {
  font-family: var(--font-display);
  font-size: clamp(30px, 5.2vw, 50px);
  line-height: 1.14;
  letter-spacing: -0.01em;
  color: var(--ink);
  margin: 0 0 22px;
  max-width: 15em;
}

.page-about .about-hero-copy .lede {
  margin: 0 0 18px;
  max-width: 34em;
}

.page-about .about-hero-copy > p:last-child {
  margin: 0;
  max-width: 34em;
  color: var(--violet-soft);
  font-size: 15px;
  line-height: 1.7;
}

.page-about .about-hero-figure {
  position: relative;
  margin: 0;
}

.page-about .about-hero-figure::before {
  content: "";
  position: absolute;
  top: -12px;
  left: -12px;
  right: 42%;
  height: 2px;
  background: var(--cyan);
}

.page-about .about-hero-figure img {
  display: block;
  width: 100%;
  height: auto;
  border: 1px solid var(--line);
  background: var(--bg-2);
  object-fit: cover;
}

.page-about .about-hero-figure .figure-caption {
  margin-top: 12px;
}

@media (min-width: 900px) {
  .page-about .about-hero-grid {
    grid-template-columns: 5fr 7fr;
    gap: 64px;
  }
}

/* ============ 章节头 ============ */
.page-about .about-head {
  display: grid;
  grid-template-columns: 1fr;
  gap: 12px;
  margin-bottom: 48px;
}

.page-about .about-head-num {
  font-size: 44px;
  line-height: 1;
  font-weight: 400;
  color: transparent;
  -webkit-text-stroke: 1px var(--cyan);
  letter-spacing: 0.02em;
}

.page-about .about-head-text .eyebrow {
  margin: 0 0 10px;
}

.page-about .about-head-title {
  font-family: var(--font-display);
  font-size: clamp(24px, 3.4vw, 38px);
  line-height: 1.22;
  letter-spacing: -0.01em;
  color: var(--ink);
  margin: 0;
  max-width: 20em;
}

@media (min-width: 760px) {
  .page-about .about-head {
    grid-template-columns: 110px 1fr;
    gap: 28px;
    align-items: start;
  }

  .page-about .about-head-num {
    font-size: 64px;
  }
}

/* ============ 01 品牌自述 ============ */
.page-about .about-intro {
  padding: 72px 0;
}

.page-about .about-intro-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 32px;
}

.page-about .about-intro-main p {
  margin: 0 0 18px;
}

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

.page-about .about-intro-aside {
  border-top: 1px solid var(--line);
  padding-top: 16px;
}

.page-about .about-intro-aside .note {
  margin: 0 0 12px;
}

.page-about .about-intro-aside .link-cyan {
  font-size: 14px;
  text-decoration: none;
  border-bottom: 1px solid var(--line);
  padding-bottom: 2px;
  transition: border-color 220ms var(--ease);
}

.page-about .about-intro-aside .link-cyan:hover {
  border-bottom-color: var(--cyan);
}

@media (min-width: 900px) {
  .page-about .about-intro-grid {
    grid-template-columns: 8fr 3fr;
    gap: 64px;
  }

  .page-about .about-intro-aside {
    align-self: start;
  }
}

/* ============ 02 版本时间线 ============ */
.page-about .about-timeline {
  padding: 80px 0;
}

.page-about .about-tl {
  display: grid;
  grid-template-columns: 1fr;
  gap: 48px;
}

.page-about .about-tl-side .eyebrow {
  margin: 0 0 12px;
}

.page-about .about-tl-side .about-head-title {
  margin-bottom: 16px;
  font-size: clamp(22px, 2.8vw, 32px);
}

.page-about .about-tl-side .note {
  margin: 0 0 28px;
  padding-left: 12px;
  border-left: 1px solid var(--line);
}

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

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

.page-about .about-tl-figure .figure-caption {
  margin-top: 10px;
}

.page-about .about-tl-list {
  list-style: none;
  margin: 0;
  padding: 0 0 0 var(--about-track);
  border-left: 1px solid var(--line);
}

.page-about .about-tl-item {
  position: relative;
  padding-bottom: 40px;
}

.page-about .about-tl-item:last-child {
  padding-bottom: 0;
}

.page-about .about-tl-node {
  position: absolute;
  left: calc((var(--about-track) + 1px) * -1 - 3px);
  top: 5px;
  width: 8px;
  height: 8px;
  background: var(--bg-2);
  border: 1px solid var(--cyan);
  transition: background 240ms var(--ease), border-color 240ms var(--ease);
}

.page-about .about-tl-item.is-current .about-tl-node {
  background: var(--amber);
  border-color: var(--amber);
}

.page-about .about-tl-item:hover .about-tl-node {
  background: var(--cyan);
}

.page-about .about-tl-item.is-current:hover .about-tl-node {
  background: var(--amber);
}

.page-about .about-tl-year {
  display: block;
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--violet);
  margin: 0 0 8px;
}

.page-about .about-tl-item.is-current .about-tl-year {
  color: var(--amber);
}

.page-about .about-tl-title {
  font-family: var(--font-display);
  font-size: 20px;
  line-height: 1.35;
  letter-spacing: -0.01em;
  color: var(--ink);
  margin: 0 0 10px;
}

.page-about .about-tl-text {
  margin: 0;
  max-width: 34em;
  font-size: 15px;
  line-height: 1.7;
  color: var(--violet-soft);
}

.page-about .about-tl-more {
  margin: 0;
  max-width: 34em;
  font-size: 13px;
  line-height: 1.65;
  color: var(--violet);
  max-height: 0;
  overflow: hidden;
  opacity: 0;
  transition: max-height 280ms var(--ease), opacity 220ms var(--ease), margin-top 280ms var(--ease);
}

.page-about .about-tl-item:hover .about-tl-more,
.page-about .about-tl-item:focus-within .about-tl-more {
  max-height: 140px;
  opacity: 1;
  margin-top: 10px;
}

@media (hover: none) {
  .page-about .about-tl-more {
    max-height: 200px;
    opacity: 1;
    margin-top: 10px;
  }
}

@media (min-width: 900px) {
  .page-about .about-tl {
    grid-template-columns: 4fr 8fr;
    gap: 72px;
  }

  .page-about .about-tl-side {
    position: sticky;
    top: 104px;
    align-self: start;
  }
}

/* ============ 03 团队构成 ============ */
.page-about .about-team {
  padding: 80px 0;
}

.page-about .about-team-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 20px;
}

.page-about .about-team-card {
  padding: 26px 22px 28px;
  background: var(--bg-2);
}

.page-about .about-team-num {
  margin: 0 0 12px;
  font-size: 26px;
  line-height: 1;
  letter-spacing: 0.02em;
  color: var(--cyan);
}

.page-about .about-team-role {
  font-family: var(--font-display);
  font-size: 18px;
  line-height: 1.35;
  color: var(--ink);
  margin: 0 0 12px;
}

.page-about .about-team-text {
  margin: 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--violet-soft);
}

.page-about .about-team-figure {
  margin: 56px 0 0;
}

.page-about .about-team-figure img {
  display: block;
  width: 100%;
  height: auto;
  border: 1px solid var(--line);
  background: var(--bg-2);
  object-fit: cover;
}

.page-about .about-team-figure .figure-caption {
  margin-top: 12px;
}

.page-about .about-team-rhythm {
  margin-top: 56px;
  padding-top: 32px;
  border-top: 1px solid var(--line);
}

.page-about .about-team-rhythm .eyebrow {
  margin: 0 0 20px;
}

.page-about .about-rhythm-list {
  list-style: none;
  margin: 0 0 24px;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
}

.page-about .about-rhythm-item {
  font-size: 14px;
  line-height: 1.75;
  color: var(--violet-soft);
  padding-left: 16px;
  border-left: 1px solid var(--line);
}

.page-about .about-rhythm-item .mono {
  display: block;
  margin-bottom: 4px;
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--amber);
}

.page-about .about-team-link {
  margin: 0;
}

.page-about .about-team-link .link-cyan {
  font-size: 14px;
  text-decoration: none;
  border-bottom: 1px solid var(--line);
  padding-bottom: 2px;
  transition: border-color 220ms var(--ease);
}

.page-about .about-team-link .link-cyan:hover {
  border-bottom-color: var(--cyan);
}

@media (min-width: 900px) {
  .page-about .about-team-grid {
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
  }

  .page-about .about-team-card:nth-child(2) {
    transform: translateY(28px);
  }

  .page-about .about-team-card:nth-child(3) {
    transform: translateY(48px);
  }

  .page-about .about-team-figure {
    margin-top: 104px;
  }

  .page-about .about-rhythm-list {
    grid-template-columns: repeat(3, 1fr);
    gap: 28px;
  }
}

/* ============ 04 栏目结构图 ============ */
.page-about .about-structure {
  padding: 80px 0;
}

.page-about .about-structure-lede {
  margin: 16px 0 0;
  max-width: 34em;
  color: var(--violet-soft);
  font-size: 15px;
}

.page-about .about-map-scroll {
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  padding-bottom: 8px;
}

.page-about .about-map {
  display: block;
  width: 100%;
  min-width: 720px;
  max-width: 900px;
  height: auto;
  margin: 0 auto;
}

.page-about .about-map-link {
  fill: none;
  stroke: var(--line);
  stroke-width: 1;
  vector-effect: non-scaling-stroke;
}

.page-about .about-map-hub {
  fill: rgba(242, 169, 59, 0.10);
  stroke: var(--amber);
  stroke-width: 1.5;
  vector-effect: non-scaling-stroke;
}

.page-about .about-map-hub-label {
  font-family: var(--font-mono);
  font-size: 15px;
  letter-spacing: 0.02em;
  fill: var(--amber-soft);
}

.page-about .about-map-node {
  fill: var(--bg-2);
  stroke: var(--cyan);
  stroke-width: 1;
  vector-effect: non-scaling-stroke;
  transition: fill 220ms var(--ease), stroke 220ms var(--ease);
}

.page-about .about-map-node.is-here {
  stroke: var(--amber);
}

.page-about .about-map-hit {
  text-decoration: none;
  cursor: pointer;
}

.page-about .about-map-hit:hover .about-map-node,
.page-about .about-map-hit:focus-visible .about-map-node {
  fill: rgba(0, 229, 208, 0.10);
  stroke: var(--cyan-soft);
}

.page-about .about-map-hit:hover .about-map-node.is-here,
.page-about .about-map-hit:focus-visible .about-map-node.is-here {
  fill: rgba(242, 169, 59, 0.12);
  stroke: var(--amber);
}

.page-about .about-map-hit:focus-visible {
  outline: none;
}

.page-about .about-map-label {
  font-family: var(--font-body);
  font-size: 15px;
  font-weight: 600;
  fill: var(--ink);
}

.page-about .about-map-sub {
  font-family: var(--font-body);
  font-size: 12px;
  fill: var(--violet);
}

/* ============ 05 内容基地 ============ */
.page-about .about-region {
  padding: 80px 0 64px;
}

.page-about .about-region-rule {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-top: 56px;
  width: 32%;
  min-width: 180px;
}

.page-about .about-region-dot {
  width: 5px;
  height: 5px;
  flex: 0 0 auto;
  background: var(--clay);
}

.page-about .about-region-line {
  flex: 1 1 auto;
  height: 1px;
  background: linear-gradient(90deg, var(--clay), rgba(181, 112, 90, 0));
}

/* ============ 下一步 ============ */
.page-about .about-next {
  padding: 56px 0 96px;
}

.page-about .about-next-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 28px;
  padding-top: 40px;
  border-top: 1px solid var(--line);
}

.page-about .about-next-copy .eyebrow {
  margin: 0 0 12px;
}

.page-about .about-next-copy .about-head-title {
  margin-bottom: 14px;
  font-size: clamp(22px, 2.8vw, 32px);
}

.page-about .about-next-copy .prose {
  margin: 0;
  color: var(--violet-soft);
  font-size: 15px;
}

.page-about .about-next-actions {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.page-about .about-next-actions .btn {
  justify-content: center;
  min-height: 44px;
  text-decoration: none;
}

@media (min-width: 900px) {
  .page-about .about-next-grid {
    grid-template-columns: 7fr 5fr;
    gap: 64px;
    align-items: center;
  }

  .page-about .about-next-actions {
    flex-direction: column;
    align-items: stretch;
  }
}

/* ============ 动效收敛 ============ */
@media (prefers-reduced-motion: reduce) {
  .page-about .about-tl-more {
    transition: none;
  }

  .page-about .about-tl-node,
  .page-about .about-map-node {
    transition: none;
  }
}
<<<END>>>