.page-about {
  --about-rail: 190px;
  --about-paper-pad: 26px;
  background-color: var(--ink-950);
  color: var(--paper-000);
  overflow-x: clip;
}

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

/* ---------- 首屏 ---------- */

.page-about .about-hero {
  padding-block: 36px 32px;
}

.page-about .about-hero__title {
  margin: 14px 0 0;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(32px, 8vw, 62px);
  line-height: 1.14;
  letter-spacing: -0.01em;
  color: var(--paper-000);
  max-width: 16em;
}

.page-about .about-hero__lede {
  margin: 22px 0 0;
  max-width: 46em;
  font-family: var(--font-body);
  font-size: 17px;
  line-height: 1.78;
  color: var(--slate-400);
}

.page-about .about-hero__stats {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(108px, 1fr));
  gap: 18px 20px;
  margin: 38px 0 0;
  padding-top: 24px;
  border-top: 1px solid var(--ink-800);
}

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

.page-about .about-stat__label {
  font-family: var(--font-board);
  font-size: 12.5px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--slate-400);
}

.page-about .about-stat__value {
  margin: 8px 0 0;
  margin-inline-start: 0;
  font-size: clamp(26px, 5vw, 38px);
  line-height: 1.1;
  letter-spacing: -0.02em;
  color: var(--cyan-400);
}

.page-about .about-hero__figure {
  margin-block: 4px 0;
  border: 1px solid var(--ink-800);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 20px), calc(100% - 20px) 100%, 0 100%);
}

.page-about .about-hero__figure img {
  width: 100%;
  object-fit: cover;
}

/* ---------- 主体骨架 ---------- */

.page-about .about-body {
  padding-block: 48px 24px;
}

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

.page-about .about-rail {
  margin-bottom: 26px;
}

.page-about .about-rail__nav .anchor-index__list {
  display: flex;
  gap: 8px;
  margin: 0;
  padding: 0 2px 8px;
  list-style: none;
  overflow-x: auto;
  scrollbar-width: thin;
}

.page-about .about-rail__nav .anchor-index__link {
  display: block;
  white-space: nowrap;
  padding: 8px 12px;
  border: 1px solid var(--ink-800);
  border-radius: 0;
  font-family: var(--font-board);
  font-size: 13px;
  letter-spacing: 0.06em;
  color: var(--slate-400);
  text-decoration: none;
  transition: color 0.18s var(--ease), border-color 0.18s var(--ease);
}

.page-about .about-rail__nav .anchor-index__link:hover,
.page-about .about-rail__nav .anchor-index__link:focus-visible,
.page-about .about-rail__nav .anchor-index__link.is-active {
  color: var(--cyan-400);
  border-color: var(--cyan-400);
}

/* ---------- 章节 ---------- */

.page-about .chapter-block {
  padding-block: 40px;
  border-top: 1px solid var(--ink-800);
  scroll-margin-top: 24px;
}

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

.page-about .chapter-block .chapter {
  display: flex;
  align-items: baseline;
  gap: 14px;
  margin-bottom: 20px;
}

.page-about .chapter-block .chapter__num {
  flex: 0 0 auto;
  font-size: 15px;
  letter-spacing: 0.08em;
  color: var(--cyan-400);
}

.page-about .chapter-block .chapter__title {
  font-family: var(--font-display);
  font-size: clamp(22px, 4.4vw, 32px);
  font-weight: 700;
  line-height: 1.32;
  color: var(--paper-000);
  margin: 0;
}

.page-about .about-text p {
  max-width: 42em;
  margin: 0 0 18px;
  font-family: var(--font-body);
  font-size: 17px;
  line-height: 1.78;
  color: var(--paper-000);
}

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

.page-about .about-text--after {
  margin-top: 26px;
}

/* ---------- 三层结构 ---------- */

.page-about .layer-list {
  list-style: none;
  margin: 28px 0 0;
  padding: 0;
  display: grid;
  gap: 12px;
}

.page-about .layer-item {
  padding: 20px 22px 22px;
  background-color: var(--ink-900);
  border-top: 2px solid var(--cyan-400);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 12px), calc(100% - 12px) 100%, 0 100%);
}

.page-about .layer-item__year {
  display: block;
  font-size: 13px;
  letter-spacing: 0.08em;
  color: var(--amber-300);
}

.page-about .layer-item__title {
  margin: 8px 0 10px;
  font-family: var(--font-display);
  font-size: 19px;
  font-weight: 700;
  color: var(--paper-000);
}

.page-about .layer-item__desc {
  margin: 0;
  font-size: 15px;
  line-height: 1.72;
  color: var(--slate-400);
}

/* ---------- 图片区 ---------- */

.page-about .about-figure {
  margin: 30px 0 0;
}

.page-about .about-figure img {
  width: 100%;
  border: 1px solid var(--ink-800);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 16px), calc(100% - 16px) 100%, 0 100%);
}

.page-about .about-figure--wide {
  margin-top: 0;
  margin-bottom: 30px;
}

.page-about .about-figure__cap {
  margin-top: 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--slate-400);
}

/* ---------- 团队比例条 ---------- */

.page-about .team-bar {
  display: flex;
  gap: 3px;
  margin-top: 30px;
}

.page-about .team-bar__seg {
  position: relative;
  flex: 1 1 0;
  min-width: 0;
  min-height: 84px;
  padding: 14px 12px 16px;
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
  gap: 4px;
  outline: none;
  cursor: default;
  transition: transform 0.18s var(--ease), filter 0.18s var(--ease);
}

.page-about .team-bar__seg--edit {
  flex-grow: 38;
  background: linear-gradient(180deg, rgba(63, 227, 210, 0.92), rgba(18, 117, 110, 0.85));
  color: var(--ink-950);
}

.page-about .team-bar__seg--check {
  flex-grow: 16;
  background: linear-gradient(180deg, rgba(240, 180, 76, 0.94), rgba(255, 122, 51, 0.8));
  color: var(--ink-950);
}

.page-about .team-bar__seg--tech {
  flex-grow: 24;
  background-color: var(--ink-900);
  border: 1px solid var(--ink-800);
  color: var(--paper-000);
}

.page-about .team-bar__seg:hover,
.page-about .team-bar__seg:focus-visible {
  transform: translateY(-2px);
  filter: brightness(1.06);
}

.page-about .team-bar__seg:focus-visible {
  box-shadow: 0 0 0 2px var(--cyan-400);
}

.page-about .team-bar__count {
  font-size: 22px;
  line-height: 1;
  letter-spacing: -0.01em;
}

.page-about .team-bar__role {
  font-family: var(--font-board);
  font-size: 13px;
  letter-spacing: 0.08em;
  opacity: 0.88;
}

.page-about .team-bar__tip {
  position: absolute;
  left: 0;
  bottom: calc(100% + 10px);
  width: max-content;
  max-width: min(260px, calc(100vw - 72px));
  padding: 10px 12px;
  background-color: var(--cream-100);
  color: var(--ink-950);
  font-family: var(--font-body);
  font-size: 13px;
  line-height: 1.62;
  opacity: 0;
  visibility: hidden;
  transform: translateY(6px);
  pointer-events: none;
  z-index: 4;
  transition: opacity 0.18s var(--ease), transform 0.18s var(--ease), visibility 0.18s;
}

.page-about .team-bar__seg:hover .team-bar__tip,
.page-about .team-bar__seg:focus-visible .team-bar__tip {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

/* ---------- 纸面区块与流程 ---------- */

.page-about .about-paper {
  margin-top: 8px;
  padding: var(--about-paper-pad);
  background-color: var(--cream-100);
  background-image:
    linear-gradient(rgba(8, 19, 31, 0.05) 1px, transparent 1px),
    linear-gradient(90deg, rgba(8, 19, 31, 0.05) 1px, transparent 1px);
  background-size: 32px 32px;
  color: var(--ink-950);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 16px), calc(100% - 16px) 100%, 0 100%);
}

.page-about .about-paper__intro {
  margin: 0;
  font-family: var(--font-display);
  font-size: 18px;
  line-height: 1.6;
  color: var(--ink-950);
}

.page-about .flow-list {
  list-style: none;
  margin: 18px 0 0;
  padding: 0;
}

.page-about .flow-step {
  display: grid;
  grid-template-columns: 34px minmax(0, 1fr);
  gap: 14px;
  padding: 18px 0;
  border-top: 1px solid rgba(8, 19, 31, 0.16);
}

.page-about .flow-step:first-child {
  border-top: 0;
  padding-top: 6px;
}

.page-about .flow-step__num {
  font-size: 13px;
  letter-spacing: 0.06em;
  color: var(--orange-500);
  padding-top: 3px;
}

.page-about .flow-step__title {
  margin: 0 0 6px;
  font-family: var(--font-board);
  font-size: 17px;
  letter-spacing: 0.06em;
  color: var(--ink-950);
}

.page-about .flow-step__body p {
  margin: 0;
  font-size: 15px;
  line-height: 1.74;
  color: var(--ink-900);
}

/* ---------- 年表 ---------- */

.page-about .timeline {
  position: relative;
  list-style: none;
  margin: 26px 0 0;
  padding: 0;
}

.page-about .timeline::before {
  content: "";
  position: absolute;
  left: 6px;
  top: 22px;
  bottom: 22px;
  width: 1px;
  background: linear-gradient(180deg, var(--cyan-700), var(--amber-300) 50%, var(--ink-800));
}

.page-about .tl-node {
  position: relative;
  padding-left: 32px;
  border-bottom: 1px solid var(--ink-800);
}

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

.page-about .tl-node::before {
  content: "";
  position: absolute;
  left: 0;
  top: 24px;
  width: 13px;
  height: 13px;
  box-sizing: border-box;
  border-radius: 50%;
  background-color: var(--ink-950);
  border: 2px solid var(--amber-300);
}

.page-about .tl-node details > summary {
  display: flex;
  align-items: baseline;
  gap: 16px;
  padding: 18px 34px 18px 0;
  list-style: none;
  cursor: pointer;
  outline: none;
}

.page-about .tl-node details > summary::-webkit-details-marker {
  display: none;
}

.page-about .tl-node details > summary::after {
  content: "+";
  position: absolute;
  right: 6px;
  top: 17px;
  font-family: var(--font-mono);
  font-size: 17px;
  color: var(--cyan-400);
}

.page-about .tl-node details[open] > summary::after {
  content: "–";
}

.page-about .tl-node details > summary:focus-visible {
  box-shadow: inset 0 0 0 2px var(--cyan-400);
}

.page-about .tl-node__year {
  flex: 0 0 auto;
  font-size: 14.5px;
  letter-spacing: 0.06em;
  color: var(--amber-300);
}

.page-about .tl-node__title {
  font-family: var(--font-display);
  font-size: 18px;
  line-height: 1.45;
  color: var(--paper-000);
  transition: color 0.18s var(--ease);
}

.page-about .tl-node details > summary:hover .tl-node__title {
  color: var(--cyan-400);
}

.page-about .tl-node__desc {
  margin: 0 0 20px;
  padding-right: 30px;
  max-width: 40em;
  font-size: 15px;
  line-height: 1.74;
  color: var(--slate-400);
}

/* ---------- 引文块 ---------- */

.page-about .about-quote {
  margin: 6px 0 0;
  padding: 22px 24px;
  border-left: 4px solid var(--orange-500);
  background-color: var(--cream-100);
  color: var(--ink-950);
}

.page-about .about-quote p {
  margin: 0;
  font-family: var(--font-display);
  font-size: 18px;
  line-height: 1.72;
}

/* ---------- 出口卡片 ---------- */

.page-about .about-links {
  list-style: none;
  margin: 26px 0 0;
  padding: 0;
  display: grid;
  gap: 12px;
}

.page-about .about-link {
  position: relative;
  display: block;
  padding: 20px 52px 22px 22px;
  background-color: var(--ink-900);
  border: 1px solid var(--ink-800);
  text-decoration: none;
  color: inherit;
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 12px), calc(100% - 12px) 100%, 0 100%);
  transition: transform 0.18s var(--ease), border-color 0.18s var(--ease);
}

.page-about .about-link:hover,
.page-about .about-link:focus-visible {
  transform: translateY(-2px);
  border-color: var(--cyan-400);
}

.page-about .about-link__kicker {
  display: block;
  font-family: var(--font-board);
  font-size: 12.5px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--amber-300);
}

.page-about .about-link__title {
  display: block;
  margin-top: 8px;
  font-family: var(--font-display);
  font-size: 20px;
  font-weight: 700;
  color: var(--paper-000);
}

.page-about .about-link__desc {
  display: block;
  margin-top: 8px;
  font-size: 14.5px;
  line-height: 1.7;
  color: var(--slate-400);
}

.page-about .about-link__arrow {
  position: absolute;
  top: 20px;
  right: 20px;
  font-family: var(--font-mono);
  font-size: 17px;
  color: var(--cyan-400);
}

/* ---------- 断点 ---------- */

@media (min-width: 720px) {
  .page-about .layer-list {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

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

  .page-about .about-paper {
    --about-paper-pad: 34px;
  }
}

@media (min-width: 1024px) {
  .page-about .about-hero {
    padding-block: 56px 44px;
  }

  .page-about .about-body {
    display: grid;
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    column-gap: 56px;
    align-items: start;
    padding-block: 72px 40px;
  }

  .page-about .about-rail {
    position: sticky;
    top: 28px;
    margin-bottom: 0;
  }

  .page-about .about-rail__nav .anchor-index__list {
    flex-direction: column;
    gap: 0;
    padding-bottom: 0;
    overflow: visible;
  }

  .page-about .about-rail__nav .anchor-index__link {
    border: 0;
    border-left: 2px solid var(--ink-800);
    padding: 10px 0 10px 14px;
    white-space: normal;
    line-height: 1.5;
  }

  .page-about .about-rail__nav .anchor-index__link:hover,
  .page-about .about-rail__nav .anchor-index__link:focus-visible,
  .page-about .about-rail__nav .anchor-index__link.is-active {
    border-left-color: var(--cyan-400);
    border-top-color: transparent;
    border-right-color: transparent;
    border-bottom-color: transparent;
  }

  .page-about .chapter-block {
    padding-block: 52px;
  }

  .page-about .about-paper {
    --about-paper-pad: 44px;
  }
}

@media (min-width: 1440px) {
  .page-about {
    --about-rail: 220px;
  }

  .page-about .about-body {
    column-gap: 76px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-link,
  .page-about .team-bar__seg,
  .page-about .team-bar__tip,
  .page-about .tl-node__title,
  .page-about .about-rail__nav .anchor-index__link {
    transition: none;
  }

  .page-about .about-link:hover,
  .page-about .team-bar__seg:hover {
    transform: none;
  }
}
<<<END>>>