.page-about {
  --ab-rail-w: 136px;
  --ab-gap: 52px;
  color: var(--db-text);
}

.page-about .ab-crumbs {
  padding-top: 18px;
}

.page-about .ab-crumbs__sep {
  margin: 0 8px;
  color: var(--db-line);
}

/* ---------- 首屏 ---------- */

.page-about .ab-hero {
  padding: clamp(26px, 5vw, 56px) 0 clamp(24px, 4vw, 40px);
  border-bottom: 1px solid var(--db-line);
}

.page-about .ab-hero__kicker {
  margin: 0 0 18px;
  font-size: 12px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--db-cyan);
}

.page-about .ab-hero__title {
  margin: 0;
  font-family: var(--db-font-head);
  font-weight: 800;
  font-size: clamp(28px, 6.6vw, 46px);
  line-height: 1.16;
  letter-spacing: -0.02em;
  max-width: 15em;
}

.page-about .ab-hero__title::after {
  content: "";
  display: block;
  width: 72px;
  height: 3px;
  margin-top: 22px;
  background: linear-gradient(90deg, var(--db-gold), rgba(233, 180, 76, 0));
}

.page-about .ab-hero__lede {
  margin: 22px 0 0;
  max-width: 36em;
  font-size: 17px;
  line-height: 1.75;
  color: var(--db-muted);
}

.page-about .ab-hero__stats {
  list-style: none;
  margin: 32px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--db-line);
  border: 1px solid var(--db-line);
}

.page-about .ab-hero__stats li {
  background: var(--db-console);
  padding: 16px 18px;
  display: flex;
  flex-direction: column;
  gap: 8px;
  min-width: 0;
}

.page-about .ab-stat__num {
  font-size: 20px;
  letter-spacing: 0.02em;
  color: var(--db-gold);
}

.page-about .ab-stat__label {
  font-size: 13px;
  line-height: 1.5;
  color: var(--db-muted);
}

@media (min-width: 720px) {
  .page-about .ab-hero__stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

/* ---------- 画布骨架 ---------- */

.page-about .ab-canvas {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
}

.page-about .ab-rail {
  position: sticky;
  top: var(--db-header-h);
  z-index: 3;
  background: var(--db-ink);
  border-bottom: 1px solid var(--db-line);
  padding: 10px 0 12px;
  overflow-x: auto;
  scrollbar-width: none;
}

.page-about .ab-rail::-webkit-scrollbar {
  display: none;
}

.page-about .ab-rail__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  gap: 4px;
  width: max-content;
}

.page-about .ab-rail__tick {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 7px 12px;
  border: 1px solid transparent;
  color: var(--db-muted);
  text-decoration: none;
  font-size: 13px;
  letter-spacing: 0.04em;
  white-space: nowrap;
  transition: color 220ms var(--db-ease), border-color 220ms var(--db-ease),
    background-color 220ms var(--db-ease);
}

.page-about .ab-rail__tick:hover,
.page-about .ab-rail__tick:focus-visible {
  color: var(--db-cyan);
  border-color: var(--db-line);
  background: var(--db-console);
}

.page-about .ab-rail__tick--year .ab-rail__label {
  font-family: var(--db-font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 14px;
  letter-spacing: 0.08em;
}

.page-about .ab-rail__tick:not(.ab-rail__tick--year) {
  color: rgba(169, 184, 206, 0.72);
}

@media (min-width: 900px) {
  .page-about .ab-canvas {
    grid-template-columns: var(--ab-rail-w) minmax(0, 1fr);
    gap: var(--ab-gap);
    align-items: start;
  }

  .page-about .ab-rail {
    position: sticky;
    top: calc(var(--db-header-h) + 34px);
    overflow: visible;
    background: transparent;
    border-bottom: 0;
    border-left: 1px solid var(--db-line);
    padding: 8px 0;
    margin-top: clamp(30px, 5vw, 58px);
  }

  .page-about .ab-rail__list {
    flex-direction: column;
    gap: 0;
    width: auto;
  }

  .page-about .ab-rail__tick {
    position: relative;
    justify-content: flex-start;
    padding: 10px 8px 10px 22px;
    border: 0;
    background: none;
  }

  .page-about .ab-rail__tick::before {
    content: "";
    position: absolute;
    left: 0;
    top: 50%;
    width: 11px;
    height: 1px;
    background: var(--db-line);
    transform: translateY(-50%);
    transition: width 220ms var(--db-ease), background-color 220ms var(--db-ease);
  }

  .page-about .ab-rail__tick:hover,
  .page-about .ab-rail__tick:focus-visible {
    background: none;
    border: 0;
    color: var(--db-cyan);
  }

  .page-about .ab-rail__tick:hover::before,
  .page-about .ab-rail__tick:focus-visible::before {
    width: 17px;
    background: var(--db-cyan);
  }
}

/* ---------- 右侧连续画布 ---------- */

.page-about .ab-stream {
  min-width: 0;
  display: flex;
  flex-direction: column;
  gap: clamp(38px, 6vw, 68px);
  padding: clamp(30px, 5vw, 58px) 0 clamp(40px, 6vw, 84px);
}

.page-about .ab-stage,
.page-about .ab-block {
  position: relative;
  padding-left: 18px;
  scroll-margin-top: calc(var(--db-header-h) + 84px);
}

.page-about .ab-stage::before,
.page-about .ab-block::before {
  content: "";
  position: absolute;
  left: 0;
  top: 8px;
  bottom: 8px;
  width: 2px;
  background: var(--db-line);
  transition: background-color 260ms var(--db-ease);
}

.page-about .ab-stage:target::before,
.page-about .ab-block:target::before {
  background: var(--db-gold);
}

.page-about .ab-stage__head {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: 16px;
}

.page-about .ab-stage__year {
  font-size: 13px;
  letter-spacing: 0.14em;
  color: var(--db-gold);
  border: 1px solid rgba(233, 180, 76, 0.34);
  padding: 3px 9px;
  background: rgba(233, 180, 76, 0.06);
}

.page-about .ab-stage__title,
.page-about .ab-block__title {
  margin: 0;
  font-family: var(--db-font-head);
  font-weight: 700;
  letter-spacing: -0.02em;
  font-size: clamp(21px, 4.4vw, 30px);
  line-height: 1.3;
}

.page-about .ab-block__title {
  margin-bottom: 16px;
  max-width: 20em;
}

.page-about .ab-stage__body p,
.page-about .ab-block__body p {
  margin: 0 0 16px;
  max-width: 34em;
  font-size: 16px;
  line-height: 1.75;
  color: var(--db-muted);
}

.page-about .ab-stage__body p:last-child,
.page-about .ab-block__body p:last-child {
  margin-bottom: 0;
}

@media (min-width: 900px) {
  .page-about .ab-stage__body p,
  .page-about .ab-block__body p {
    font-size: 17px;
  }
}

/* ---------- 图 ---------- */

.page-about .ab-figure {
  margin: 26px 0 0;
}

.page-about .ab-figure--inline {
  max-width: 520px;
}

.page-about .ab-figure img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
  filter: saturate(0.9) contrast(1.04);
}

.page-about .ab-figure .db-figure__cap {
  margin-top: 10px;
  font-size: 13px;
  line-height: 1.6;
  color: rgba(169, 184, 206, 0.78);
}

/* ---------- 团队比例条 ---------- */

.page-about .ab-bar__row {
  display: flex;
  height: 52px;
  margin: 24px 0 14px;
  border: 1px solid var(--db-line);
  background: var(--db-console);
  overflow: hidden;
}

.page-about .ab-bar__seg {
  display: flex;
  align-items: center;
  gap: 12px;
  min-width: 0;
  padding: 0 16px;
  overflow: hidden;
  transition: filter 220ms var(--db-ease);
}

.page-about .ab-bar__seg:hover {
  filter: brightness(1.14);
}

.page-about .ab-bar__seg--dev {
  flex: 22 1 0;
  background: linear-gradient(90deg, rgba(233, 180, 76, 0.92), rgba(233, 180, 76, 0.46));
  color: #1b1206;
}

.page-about .ab-bar__seg--ops {
  flex: 18 1 0;
  background: linear-gradient(90deg, rgba(63, 216, 206, 0.5), rgba(63, 216, 206, 0.22));
  color: var(--db-text);
}

.page-about .ab-bar__val {
  font-size: 16px;
  letter-spacing: 0.04em;
  flex: none;
}

.page-about .ab-bar__tip {
  font-size: 13px;
  opacity: 0.86;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

@media (max-width: 640px) {
  .page-about .ab-bar__tip {
    display: none;
  }
}

.page-about .ab-legend {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 8px;
}

.page-about .ab-legend li {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 14px;
  color: var(--db-muted);
}

.page-about .ab-legend b {
  color: var(--db-text);
  font-weight: 500;
}

.page-about .ab-legend__dot {
  width: 10px;
  height: 10px;
  flex: none;
}

.page-about .ab-legend__dot--dev {
  background: var(--db-gold);
}

.page-about .ab-legend__dot--ops {
  background: var(--db-cyan);
}

@media (min-width: 641px) {
  .page-about .ab-legend {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

/* ---------- 判断标准 ---------- */

.page-about .ab-principles {
  display: grid;
  gap: 1px;
  background: var(--db-line);
  border: 1px solid var(--db-line);
  margin-bottom: 26px;
}

.page-about .ab-principle {
  background: var(--db-console);
  padding: 20px 20px 22px;
}

.page-about .ab-principle h3 {
  margin: 0 0 10px;
  font-family: var(--db-font-head);
  font-weight: 700;
  font-size: 17px;
  letter-spacing: -0.01em;
}

.page-about .ab-principle p {
  margin: 0;
  font-size: 15px;
  line-height: 1.75;
  color: var(--db-muted);
}

@media (min-width: 860px) {
  .page-about .ab-principles {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

.page-about .ab-quote {
  margin: 0;
  padding: 4px 0 4px 22px;
  border-left: 3px solid var(--db-gold);
  background: linear-gradient(90deg, rgba(233, 180, 76, 0.07), rgba(233, 180, 76, 0));
}

.page-about .ab-quote p {
  margin: 0;
  max-width: 26em;
  font-family: var(--db-font-head);
  font-weight: 600;
  font-size: clamp(19px, 3.4vw, 24px);
  line-height: 1.6;
  letter-spacing: -0.01em;
  color: var(--db-text);
}

/* ---------- 更新节奏 ---------- */

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

.page-about .ab-rhythm li {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 16px 0;
  border-bottom: 1px solid var(--db-line);
}

.page-about .ab-rhythm__key {
  font-size: 18px;
  letter-spacing: 0.03em;
  color: var(--db-cyan);
}

.page-about .ab-rhythm__desc {
  font-size: 15px;
  line-height: 1.7;
  color: var(--db-muted);
}

@media (min-width: 760px) {
  .page-about .ab-rhythm li {
    flex-direction: row;
    align-items: baseline;
    gap: 26px;
  }

  .page-about .ab-rhythm__key {
    flex: none;
    width: 116px;
    text-align: right;
  }

  .page-about .ab-rhythm__desc {
    max-width: 32em;
  }
}

/* ---------- 延伸阅读 ---------- */

.page-about .ab-next {
  padding: 26px 0 0;
  border-top: 2px solid var(--db-panel);
}

.page-about .ab-next__title {
  margin: 0 0 18px;
  font-family: var(--db-font-head);
  font-weight: 700;
  font-size: 17px;
  letter-spacing: 0.02em;
  color: var(--db-muted);
}

.page-about .ab-next__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--db-line);
  border: 1px solid var(--db-line);
}

.page-about .ab-next__list li {
  background: var(--db-ink);
}

.page-about .ab-next__list a {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 18px 18px 20px;
  text-decoration: none;
  color: var(--db-text);
  font-family: var(--db-font-head);
  font-weight: 700;
  font-size: 16px;
  letter-spacing: -0.01em;
  transition: background-color 220ms var(--db-ease), box-shadow 220ms var(--db-ease);
}

.page-about .ab-next__list a span {
  font-family: var(--db-font-body);
  font-weight: 400;
  font-size: 14px;
  line-height: 1.6;
  color: var(--db-muted);
  transition: color 220ms var(--db-ease);
}

.page-about .ab-next__list a:hover,
.page-about .ab-next__list a:focus-visible {
  background: var(--db-console);
  box-shadow: inset 0 -2px 0 var(--db-gold);
}

.page-about .ab-next__list a:hover span,
.page-about .ab-next__list a:focus-visible span {
  color: var(--db-cyan);
}

@media (min-width: 680px) {
  .page-about .ab-next__list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 1000px) {
  .page-about .ab-next__list {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

/* ---------- 滚动点亮（渐进增强） ---------- */

@supports (animation-timeline: view()) {
  .page-about .ab-stage,
  .page-about .ab-block {
    animation: ab-lit linear both;
    animation-timeline: view();
    animation-range: entry 4% cover 42%;
  }

  @keyframes ab-lit {
    from {
      opacity: 0.5;
    }
    to {
      opacity: 1;
    }
  }

  .page-about .ab-quote {
    animation: ab-quote-in linear both;
    animation-timeline: view();
    animation-range: entry 8% cover 34%;
  }

  @keyframes ab-quote-in {
    from {
      opacity: 0;
      transform: translateY(8px);
    }
    to {
      opacity: 1;
      transform: none;
    }
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .ab-stage,
  .page-about .ab-block,
  .page-about .ab-quote {
    animation: none !important;
  }
}
<<<END>>>