.page-about {
  background: var(--ink);
  color: var(--paper);
  overflow-x: hidden;
}

.page-about h1,
.page-about h2,
.page-about h3 {
  margin: 0;
  font-weight: 800;
  letter-spacing: -0.01em;
  line-height: 1.22;
}

.page-about h1 {
  font-size: clamp(28px, 4.6vw, 42px);
  margin-top: 14px;
}

.page-about h2 {
  font-size: clamp(22px, 3vw, 30px);
  margin-top: 10px;
}

.page-about h3 {
  font-size: 18px;
}

.page-about p {
  margin: 0 0 1.1em;
  font-size: 16px;
  line-height: 1.75;
  color: rgba(244, 241, 232, 0.84);
}

.page-about .lede {
  font-size: 17px;
  line-height: 1.8;
  color: rgba(244, 241, 232, 0.9);
}

.ab-sec-num {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--gold);
  margin: 0;
}

.ab-sec-head {
  margin-bottom: 28px;
}

.ab-sec-head .note {
  max-width: 56ch;
  margin-top: 10px;
}

/* 首屏 */
.ab-hero {
  padding: 24px 0 56px;
}

.ab-hero-grid {
  display: grid;
  gap: 36px;
  grid-template-columns: minmax(0, 1fr);
  align-items: start;
}

.ab-hero-main {
  max-width: 62ch;
}

.ab-facts {
  list-style: none;
  margin: 0;
  padding: 0;
  border-top: 1px solid var(--line);
}

.ab-facts li {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 2px;
  padding: 16px 0;
  border-bottom: 1px solid var(--line);
}

.ab-fact-num {
  font-size: 24px;
  color: var(--ice);
  font-weight: 600;
}

.ab-fact-key {
  font-size: 14px;
  font-weight: 700;
  color: var(--gold-soft);
}

.ab-fact-txt {
  font-size: 13px;
  line-height: 1.6;
  color: var(--stone);
}

/* 起点 */
.ab-origin {
  padding: 8px 0 56px;
}

.ab-origin-grid {
  display: grid;
  gap: 24px;
  grid-template-columns: minmax(0, 1fr);
}

.ab-origin-body p {
  max-width: 52ch;
}

.ab-origin-body p:nth-child(2) {
  max-width: 44ch;
}

.ab-origin-note {
  padding-left: 16px;
  border-left: 2px solid var(--line);
  font-size: 14px !important;
  color: var(--stone) !important;
}

/* 时间线 */
.ab-timeline {
  padding: 56px 0;
  border-top: 1px solid var(--line);
}

.ab-tl-figure {
  margin: 0 0 40px;
}

.ab-tl-figure img,
.ab-steps-figure img,
.ab-close-figure img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  object-fit: cover;
}

.ab-tl-list {
  position: relative;
  list-style: none;
  margin: 0;
  padding: 0 0 0 24px;
}

.ab-tl-list::before {
  content: "";
  position: absolute;
  left: 0;
  top: 6px;
  bottom: 6px;
  width: 2px;
  background: var(--gold);
  opacity: 0.55;
}

.ab-tl-node {
  position: relative;
  padding-bottom: 36px;
}

.ab-tl-node::before {
  content: "";
  position: absolute;
  left: -28px;
  top: 8px;
  width: 8px;
  height: 8px;
  background: var(--ink);
  border: 2px solid var(--gold);
  transition: background 180ms var(--ease), transform 180ms var(--ease);
}

.ab-tl-mark {
  display: inline-block;
  text-decoration: none;
  color: var(--ice);
  font-family: var(--font-mono);
  font-size: 18px;
  font-weight: 600;
  padding: 2px 0;
  border-bottom: 1px solid transparent;
  transition: color 180ms var(--ease), border-color 180ms var(--ease);
}

.ab-tl-mark:hover,
.ab-tl-mark:focus-visible {
  color: var(--gold-soft);
  border-bottom-color: var(--gold);
}

.ab-tl-body {
  max-width: 58ch;
  margin-top: 8px;
}

.ab-tl-node:nth-child(1) .ab-tl-body {
  max-width: 42ch;
}

.ab-tl-node:nth-child(2) .ab-tl-body {
  max-width: 48ch;
}

.ab-tl-node:nth-child(3) .ab-tl-body {
  max-width: 66ch;
}

.ab-tl-title {
  color: var(--paper);
  margin-bottom: 6px !important;
}

.ab-tl-node:target .ab-tl-title {
  color: var(--gold-soft);
}

.ab-tl-node:target::before {
  background: var(--gold);
  transform: scale(1.3);
}

/* 团队 */
.ab-team {
  padding: 56px 0;
  background: var(--panel);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.ab-bar {
  display: flex;
  flex-direction: column;
  gap: 6px;
  margin-bottom: 28px;
}

.ab-seg {
  position: relative;
  flex: 0 0 auto;
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 10px;
  padding: 12px 14px;
  background: var(--ink);
  border: 1px solid var(--line);
  transition: background 180ms var(--ease), border-color 180ms var(--ease), transform 180ms var(--ease);
}

.ab-seg-name {
  font-size: 14px;
  font-weight: 700;
  color: var(--paper);
}

.ab-seg-num {
  font-size: 13px;
  color: var(--ice);
}

.ab-seg-tip {
  display: block;
  flex-basis: 100%;
  font-size: 13px;
  line-height: 1.6;
  color: var(--stone);
  margin-top: 6px;
}

.ab-seg:hover,
.ab-seg:focus-visible {
  background: #123f36;
  border-color: var(--gold);
  transform: translateY(-2px);
  outline: none;
}

.ab-seg:focus-visible {
  box-shadow: 0 0 0 2px var(--ice);
}

.ab-team-tail {
  max-width: 64ch;
  font-size: 15px;
}

/* 三关 */
.ab-steps {
  padding: 56px 0;
}

.ab-steps-grid {
  display: grid;
  gap: 32px;
  grid-template-columns: minmax(0, 1fr);
}

.ab-steps-col {
  display: block;
}

.ab-step {
  position: relative;
  background: var(--paper);
  color: var(--paper-ink);
  border: 1px solid var(--line);
  padding: 20px 20px 18px;
  margin-bottom: 30px;
  transition: transform 180ms var(--ease), box-shadow 180ms var(--ease);
}

.ab-step:last-child {
  margin-bottom: 0;
}

.ab-step::after {
  content: "";
  position: absolute;
  left: 28px;
  bottom: -30px;
  height: 30px;
  width: 0;
  border-left: 1px dashed var(--gold);
  opacity: 0.7;
}

.ab-step:last-child::after {
  display: none;
}

.ab-step:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 0 rgba(4, 16, 13, 0.35);
}

.ab-step h3 {
  color: var(--paper-ink);
  margin-bottom: 6px !important;
}

.ab-step p {
  margin: 0;
  font-size: 15px;
  color: var(--stone-paper);
}

.ab-step-no {
  display: block;
  font-size: 12px;
  letter-spacing: 0.08em;
  color: #8a6f14;
  margin-bottom: 8px;
}

.ab-steps-side {
  display: flex;
  flex-direction: column;
  gap: 18px;
}

.ab-steps-figure {
  margin: 0;
}

.ab-steps-text {
  font-size: 14px;
  color: var(--stone);
  border-top: 1px solid var(--line);
  padding-top: 14px;
  margin: 0;
}

/* 四条做法 */
.ab-principles {
  padding: 48px 0 56px;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.ab-principles-inner {
  max-width: 100%;
}

.ab-principles .ab-sec-num {
  color: #8a6f14;
}

.ab-principles-list {
  max-width: 68ch;
}

.ab-principles .fold {
  margin-bottom: 10px;
  border: 1px solid rgba(30, 90, 78, 0.35);
}

.ab-principles .fold-body p {
  font-size: 15px;
}

/* 协作 */
.ab-network {
  padding: 56px 0;
}

.ab-network-grid {
  display: grid;
  gap: 32px;
  grid-template-columns: minmax(0, 1fr);
}

.ab-network-body p {
  max-width: 58ch;
}

.ab-network-link {
  margin-top: 22px;
}

.ab-quote {
  margin: 0;
  padding: 22px 22px 10px 22px;
  background: var(--paper);
  border-left: 3px solid var(--gold);
  align-self: start;
}

.ab-quote p {
  color: var(--paper-ink);
  font-size: 17px;
  font-weight: 700;
  line-height: 1.7;
  max-width: 30ch;
}

/* 结尾 */
.ab-close {
  padding: 56px 0 64px;
  border-top: 1px solid var(--line);
}

.ab-close-grid {
  display: grid;
  gap: 32px;
  grid-template-columns: minmax(0, 1fr);
  align-items: center;
}

.ab-close-body p {
  max-width: 56ch;
}

.ab-close-links {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin: 24px 0 0;
  padding: 0;
}

.ab-close-figure {
  margin: 0;
}

@media (min-width: 760px) {
  .ab-facts li {
    grid-template-columns: 118px minmax(0, 1fr);
    align-items: baseline;
    gap: 4px 16px;
  }

  .ab-fact-num {
    grid-row: span 2;
    align-self: center;
  }

  .ab-bar {
    flex-direction: row;
    align-items: stretch;
    gap: 4px;
    padding-bottom: 6px;
  }

  .ab-seg {
    flex-direction: column;
    align-items: flex-start;
    justify-content: flex-start;
    gap: 4px;
    padding: 14px 12px;
  }

  .ab-seg--data { flex: 9 1 0%; }
  .ab-seg--doc  { flex: 4 1 0%; }
  .ab-seg--tech { flex: 11 1 0%; }
  .ab-seg--cs   { flex: 4 1 0%; }

  .ab-seg-tip {
    position: absolute;
    left: 0;
    top: calc(100% + 10px);
    width: 230px;
    margin: 0;
    padding: 12px 14px;
    background: var(--paper);
    color: var(--stone-paper);
    border: 1px solid var(--line);
    opacity: 0;
    visibility: hidden;
    transform: translateY(-4px);
    transition: opacity 180ms var(--ease), transform 180ms var(--ease), visibility 180ms;
    z-index: 6;
    font-size: 13px;
  }

  .ab-seg--cs .ab-seg-tip {
    left: auto;
    right: 0;
  }

  .ab-seg:hover .ab-seg-tip,
  .ab-seg:focus-visible .ab-seg-tip,
  .ab-seg:focus-within .ab-seg-tip {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
  }
}

@media (min-width: 960px) {
  .ab-hero {
    padding: 44px 0 72px;
  }

  .ab-hero-grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 4fr);
    gap: 64px;
  }

  .ab-origin {
    padding-bottom: 72px;
  }

  .ab-origin-grid {
    grid-template-columns: minmax(0, 4fr) minmax(0, 8fr);
    gap: 48px;
  }

  .ab-origin-lead {
    position: sticky;
    top: 96px;
    align-self: start;
  }

  .ab-timeline,
  .ab-steps,
  .ab-network {
    padding: 80px 0;
  }

  .ab-team {
    padding: 80px 0;
  }

  .ab-tl-figure {
    margin-bottom: 48px;
  }

  .ab-tl-list {
    padding-left: 32px;
  }

  .ab-tl-node::before {
    left: -37px;
  }

  .ab-tl-mark {
    font-size: 20px;
  }

  .ab-steps-grid {
    grid-template-columns: minmax(0, 1.3fr) minmax(0, 0.9fr);
    gap: 48px;
    align-items: start;
  }

  .ab-steps-side {
    position: sticky;
    top: 96px;
  }

  .ab-network-grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 4fr);
    gap: 56px;
  }

  .ab-close-grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    gap: 48px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .ab-seg,
  .page-about .ab-step,
  .page-about .ab-tl-node::before,
  .page-about .ab-seg-tip {
    transition: opacity 140ms linear;
    transform: none !important;
  }
}
<<<END>>>