.page-about {
  --ab-rail: 172px;
  --ab-chapter-gap: clamp(64px, 11vw, 156px);
  --ab-card: var(--panel);
}

/* ---------- 首屏 ---------- */
.page-about .ab-hero {
  position: relative;
  padding-block: clamp(20px, 3.5vw, 40px) clamp(40px, 7vw, 88px);
}

.page-about .ab-hero .crumbs {
  margin-bottom: clamp(20px, 3vw, 32px);
}

.page-about .ab-hero__title {
  margin: 0 0 clamp(16px, 2.4vw, 24px);
  max-width: 18ch;
  font-size: clamp(30px, 5.6vw, 54px);
  line-height: 1.16;
  letter-spacing: -0.022em;
  font-weight: 900;
  color: var(--paper);
}

.page-about .ab-hero__lead {
  margin: 0;
  max-width: 62ch;
  font-size: clamp(15px, 1.6vw, 17px);
  line-height: 1.85;
  color: var(--steel);
}

.page-about .ab-stats {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: 1px;
  margin: clamp(26px, 4vw, 42px) 0 0;
  padding: 0;
  list-style: none;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .ab-stat {
  background: var(--ink-950);
  padding: 16px 18px;
}

.page-about .ab-stat__num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(21px, 2.6vw, 27px);
  line-height: 1.2;
  color: var(--amber);
  font-variant-numeric: tabular-nums;
  letter-spacing: 0.01em;
}

.page-about .ab-stat__label {
  display: block;
  margin-top: 8px;
  font-size: 12.5px;
  line-height: 1.5;
  letter-spacing: 0.05em;
  color: var(--steel);
}

/* ---------- 主体栅格 ---------- */
.page-about .ab-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  align-items: start;
}

.page-about .ab-flow {
  min-width: 0;
}

/* ---------- 左侧章节索引 ---------- */
.page-about .ab-rail {
  margin-bottom: clamp(28px, 5vw, 44px);
  padding-bottom: 18px;
  border-bottom: 1px solid var(--line);
}

.page-about .ab-rail__label {
  margin: 0 0 12px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.18em;
  color: var(--steel);
  opacity: 0.72;
}

.page-about .ab-rail__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 2px 10px;
}

.page-about .ab-rail__link {
  display: flex;
  align-items: baseline;
  gap: 9px;
  padding: 7px 8px 7px 10px;
  border-left: 1px solid transparent;
  font-size: 13px;
  line-height: 1.5;
  color: var(--steel);
  text-decoration: none;
  transition: color 160ms ease, border-color 160ms ease, background 160ms ease;
}

.page-about .ab-rail__link:hover,
.page-about .ab-rail__link:focus-visible {
  color: var(--paper);
  border-left-color: var(--amber);
  background: linear-gradient(90deg, rgba(246, 168, 28, 0.1), rgba(246, 168, 28, 0) 82%);
}

.page-about .ab-rail__no {
  flex: none;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--amber);
}

.page-about .ab-rail__top {
  display: inline-block;
  margin-top: 16px;
  padding: 5px 0;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.1em;
  color: var(--steel);
  text-decoration: none;
  border-bottom: 1px solid var(--line);
  transition: color 160ms ease, border-color 160ms ease;
}

.page-about .ab-rail__top:hover,
.page-about .ab-rail__top:focus-visible {
  color: var(--amber);
  border-bottom-color: var(--amber);
}

/* ---------- 章节骨架 ---------- */
.page-about .ab-chapter {
  position: relative;
  scroll-margin-top: calc(var(--header-h) + 32px);
}

.page-about .ab-chapter + .ab-chapter {
  margin-top: var(--ab-chapter-gap);
  padding-top: clamp(34px, 5.5vw, 64px);
}

.page-about .ab-chapter + .ab-chapter::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 1px;
  background: linear-gradient(90deg, var(--line), rgba(29, 46, 68, 0) 82%);
}

.page-about .ab-ghost {
  position: absolute;
  top: -0.3em;
  right: 0;
  font-family: var(--font-mono);
  font-size: clamp(70px, 12vw, 156px);
  line-height: 0.78;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--paper);
  opacity: 0.05;
  pointer-events: none;
  user-select: none;
  z-index: 0;
}

.page-about .ab-chapter__head {
  position: relative;
  z-index: 1;
  margin-bottom: clamp(22px, 3.6vw, 40px);
}

.page-about .ab-chapter__kicker {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.18em;
  color: var(--amber);
}

.page-about .ab-chapter__title {
  margin: 0;
  max-width: 22ch;
  font-size: clamp(23px, 3.4vw, 33px);
  line-height: 1.28;
  letter-spacing: -0.015em;
  font-weight: 800;
  color: var(--paper);
}

.page-about .ab-chapter__lede {
  margin: 12px 0 0;
  max-width: 54ch;
  font-size: clamp(14.5px, 1.5vw, 16.5px);
  line-height: 1.8;
  color: var(--steel);
}

/* ---------- 正文块 ---------- */
.page-about .ab-body {
  position: relative;
  z-index: 1;
}

.page-about .ab-body p {
  margin: 0 0 16px;
  max-width: 66ch;
  font-size: 15.5px;
  line-height: 1.88;
  color: rgba(244, 241, 233, 0.86);
}

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

.page-about .ab-body strong {
  font-weight: 700;
  color: var(--paper);
}

.page-about .ab-body + .ab-body {
  margin-top: 22px;
}

.page-about .ab-note {
  margin: 18px 0 0;
  padding-left: 14px;
  max-width: 62ch;
  border-left: 1px solid var(--line);
  font-size: 13.5px;
  line-height: 1.72;
  color: var(--steel);
}

.page-about .ab-body-link {
  margin: 18px 0 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--steel);
}

.page-about .ab-inline-link {
  color: var(--amber-soft);
  text-decoration: none;
  border-bottom: 1px solid rgba(255, 208, 122, 0.42);
  transition: color 160ms ease, border-color 160ms ease;
}

.page-about .ab-inline-link:hover,
.page-about .ab-inline-link:focus-visible {
  color: var(--amber);
  border-bottom-color: var(--amber);
}

/* ---------- 配图 ---------- */
.page-about .ab-figure {
  position: relative;
  margin: clamp(22px, 3.4vw, 34px) 0 0;
  border: 1px solid var(--line);
  background: var(--ink-950);
  overflow: hidden;
}

.page-about .ab-figure::after {
  content: "";
  position: absolute;
  inset: auto 0 0 0;
  height: 40%;
  background: linear-gradient(180deg, rgba(5, 8, 12, 0), rgba(5, 8, 12, 0.55));
  pointer-events: none;
}

.page-about .ab-figure img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
  filter: saturate(0.92) contrast(1.06);
}

.page-about .ab-figure__cap {
  position: relative;
  z-index: 1;
  margin: 0;
  padding: 10px 14px;
  border-top: 1px solid var(--line);
  font-family: var(--font-mono);
  font-size: 11.5px;
  line-height: 1.6;
  letter-spacing: 0.06em;
  color: var(--steel);
}

/* ---------- 时间轴 ---------- */
.page-about .ab-timeline {
  position: relative;
  list-style: none;
  margin: 0;
  padding: 4px 0 4px 34px;
}

.page-about .ab-timeline::before {
  content: "";
  position: absolute;
  left: 7px;
  top: 10px;
  bottom: 10px;
  width: 1px;
  background: linear-gradient(180deg, var(--amber), var(--line) 34%, var(--line));
}

.page-about .ab-tl {
  position: relative;
  padding: 14px 16px;
  border: 1px solid transparent;
  transition: border-color 180ms ease, background 180ms ease;
}

.page-about .ab-tl::before {
  content: "";
  position: absolute;
  left: -32px;
  top: 24px;
  width: 8px;
  height: 8px;
  background: var(--ink-900);
  border: 1px solid var(--amber);
  transform: rotate(45deg);
  transition: background 180ms ease, box-shadow 180ms ease;
}

.page-about .ab-tl:hover,
.page-about .ab-tl:focus-within {
  border-color: var(--line);
  background: linear-gradient(90deg, rgba(18, 32, 50, 0.92), rgba(18, 32, 50, 0) 88%);
}

.page-about .ab-tl:hover::before,
.page-about .ab-tl:focus-within::before {
  background: var(--amber);
  box-shadow: 0 0 14px rgba(246, 168, 28, 0.6);
}

.page-about .ab-tl__ver {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 17px;
  letter-spacing: 0.12em;
  color: var(--amber);
}

.page-about .ab-tl__name {
  margin: 6px 0 8px;
  font-size: 16.5px;
  line-height: 1.5;
  font-weight: 700;
  color: var(--paper);
}

.page-about .ab-tl__desc {
  margin: 0;
  max-width: 60ch;
  font-size: 14.5px;
  line-height: 1.78;
  color: var(--steel);
}

/* ---------- 四步工序 ---------- */
.page-about .ab-steps {
  list-style: none;
  margin: clamp(20px, 3vw, 30px) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .ab-step {
  position: relative;
  background: var(--ab-card);
  padding: 16px 18px 20px;
}

.page-about .ab-step::after {
  content: "";
  position: absolute;
  top: 20px;
  right: 16px;
  width: 7px;
  height: 7px;
  border-top: 1px solid var(--amber);
  border-right: 1px solid var(--amber);
  transform: rotate(45deg);
  opacity: 0.5;
}

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

.page-about .ab-step__no {
  display: block;
  font-size: 11px;
  letter-spacing: 0.18em;
  color: var(--amber);
}

.page-about .ab-step__name {
  margin: 7px 0 8px;
  font-size: 15px;
  line-height: 1.4;
  font-weight: 700;
  color: var(--paper);
}

.page-about .ab-step p {
  margin: 0;
  font-size: 13.5px;
  line-height: 1.72;
  color: var(--steel);
}

/* ---------- 团队 ---------- */
.page-about .filter-bar {
  margin-top: clamp(22px, 3.2vw, 32px);
  margin-bottom: 4px;
}

.page-about .ab-team__grid {
  list-style: none;
  margin: 14px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 10px;
}

.page-about .ab-team__item {
  background: var(--ab-card);
  border: 1px solid var(--line);
  padding: 16px 18px 18px;
  transition: border-color 180ms ease, background 180ms ease;
}

.page-about .ab-team__item:hover {
  border-color: rgba(246, 168, 28, 0.5);
  background: var(--ink-950);
}

.page-about .ab-team__count {
  display: block;
  font-size: 22px;
  line-height: 1.2;
  color: var(--amber);
  font-variant-numeric: tabular-nums;
}

.page-about .ab-team__name {
  margin: 8px 0 8px;
  font-size: 16px;
  line-height: 1.45;
  font-weight: 700;
  color: var(--paper);
}

.page-about .ab-team__desc {
  margin: 0;
  font-size: 13.5px;
  line-height: 1.72;
  color: var(--steel);
}

/* ---------- 合作与认可 ---------- */
.page-about .ab-partner-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .ab-partner {
  background: var(--ab-card);
  padding: 18px 20px 20px;
}

.page-about .ab-partner__num {
  display: block;
  font-size: clamp(20px, 2.6vw, 26px);
  line-height: 1.2;
  color: var(--amber);
  font-variant-numeric: tabular-nums;
  letter-spacing: 0.04em;
}

.page-about .ab-partner__text {
  margin: 10px 0 0;
  font-size: 13.5px;
  line-height: 1.75;
  color: var(--steel);
}

.page-about .ab-honors {
  list-style: none;
  margin: clamp(22px, 3.2vw, 32px) 0 0;
  padding: 0;
  display: grid;
  gap: 12px;
}

.page-about .ab-honors li {
  position: relative;
  padding-left: 20px;
  max-width: 64ch;
  font-size: 14.5px;
  line-height: 1.78;
  color: rgba(244, 241, 233, 0.85);
}

.page-about .ab-honors li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 12px;
  width: 9px;
  height: 1px;
  background: var(--amber);
}

/* ---------- 服务细节 ---------- */
.page-about .ab-practices {
  list-style: none;
  margin: 0;
  padding: 0;
  border-top: 1px solid var(--line);
}

.page-about .ab-practice {
  display: grid;
  gap: 6px;
  padding: 16px 0;
  border-bottom: 1px solid var(--line);
}

.page-about .ab-practice__label {
  font-size: 11.5px;
  letter-spacing: 0.16em;
  color: var(--amber);
}

.page-about .ab-practice__text {
  margin: 0;
  max-width: 66ch;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--steel);
}

.page-about .ab-quote {
  margin: clamp(24px, 3.6vw, 36px) 0 0;
  padding: 6px 0 6px 20px;
  max-width: 58ch;
  border-left: 2px solid var(--amber);
  font-size: clamp(16px, 1.9vw, 19px);
  line-height: 1.8;
  color: var(--paper);
}

/* ---------- 收尾入口 ---------- */
.page-about .ab-cta {
  margin-top: clamp(46px, 7vw, 84px);
  padding: clamp(22px, 4vw, 38px);
  border: 1px solid var(--line);
  border-left: 2px solid var(--amber);
  background: linear-gradient(120deg, rgba(246, 168, 28, 0.08), rgba(18, 32, 50, 0.6) 48%, rgba(18, 32, 50, 0) 100%);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 20px 32px;
}

.page-about .ab-cta__copy {
  min-width: 0;
  flex: 1 1 260px;
}

.page-about .ab-cta__title {
  margin: 0 0 8px;
  font-size: clamp(17px, 2.1vw, 20px);
  line-height: 1.5;
  font-weight: 700;
  color: var(--paper);
}

.page-about .ab-cta__text {
  margin: 0;
  max-width: 50ch;
  font-size: 14px;
  line-height: 1.75;
  color: var(--steel);
}

.page-about .ab-cta__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

/* ---------- 断点 ---------- */
@media (min-width: 640px) {
  .page-about .ab-team__grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

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

@media (min-width: 760px) {
  .page-about .ab-steps {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .ab-practice {
    grid-template-columns: 132px minmax(0, 1fr);
    gap: 4px 24px;
    align-items: baseline;
  }
}

@media (min-width: 1024px) {
  .page-about .ab-layout {
    grid-template-columns: var(--ab-rail) minmax(0, 1fr);
    column-gap: clamp(36px, 4.5vw, 80px);
  }

  .page-about .ab-rail {
    position: sticky;
    top: calc(var(--header-h) + 28px);
    align-self: start;
    margin-bottom: 0;
    padding-bottom: 0;
    border-bottom: none;
  }

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

  .page-about .ab-rail__link {
    padding: 8px 10px 8px 12px;
    font-size: 13.5px;
  }

  .page-about .ab-ghost {
    right: 0.02em;
  }
}

@media (min-width: 1200px) {
  .page-about .ab-hero__lead {
    font-size: 17px;
  }

  .page-about .ab-body p {
    font-size: 16px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .ab-rail__link,
  .page-about .ab-tl,
  .page-about .ab-tl::before,
  .page-about .ab-team__item,
  .page-about .ab-inline-link,
  .page-about .ab-rail__top {
    transition: none;
  }
}
<<<END>>>