.page-about {
  --ab-hairline: rgba(40, 72, 59, 0.72);
  --ab-body-text: rgba(243, 239, 230, 0.82);
  position: relative;
  background-image:
    repeating-linear-gradient(to right, rgba(40, 72, 59, 0.22) 0 1px, transparent 1px 96px);
  background-position: center top;
  background-repeat: repeat-y;
  padding-bottom: clamp(40px, 6vw, 88px);
}

.page-about .ab-crumbs-wrap {
  padding-top: clamp(16px, 2.4vw, 26px);
}

.page-about .ab-crumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--grey);
}

.page-about .ab-crumbs a {
  color: var(--grey);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.page-about .ab-crumbs a:hover,
.page-about .ab-crumbs a:focus-visible {
  color: var(--lime);
  border-bottom-color: var(--lime);
}

.page-about .ab-crumbs__sep {
  color: var(--grid);
}

.page-about .ab-crumbs__current {
  color: var(--cream);
}

/* ---------- 首屏框景 ---------- */
.page-about .ab-hero {
  padding-top: clamp(14px, 2.4vw, 24px);
}

.page-about .ab-hero__frame {
  position: relative;
  border: 1px solid var(--ab-hairline);
  padding: clamp(18px, 3vw, 42px);
  background:
    radial-gradient(120% 140% at 88% 6%, rgba(30, 106, 90, 0.28) 0%, rgba(6, 31, 25, 0) 58%),
    rgba(10, 13, 12, 0.38);
}

.page-about .ab-hero__frame::before,
.page-about .ab-hero__frame::after {
  content: "";
  position: absolute;
  width: 58px;
  height: 58px;
  pointer-events: none;
}

.page-about .ab-hero__frame::before {
  top: -1px;
  left: -1px;
  border-top: 2px solid var(--lime);
  border-left: 2px solid var(--lime);
}

.page-about .ab-hero__frame::after {
  right: -1px;
  bottom: -1px;
  border-right: 2px solid var(--orange);
  border-bottom: 2px solid var(--orange);
}

.page-about .ab-hero__grid {
  display: grid;
  gap: clamp(22px, 3.4vw, 44px);
}

.page-about .ab-hero__title {
  margin: 14px 0 0;
  font-family: var(--font-display);
  font-weight: 300;
  font-size: clamp(32px, 6.4vw, 68px);
  line-height: 1.03;
  letter-spacing: -0.02em;
  color: var(--cream);
  max-width: 18ch;
}

.page-about .ab-hero__lede {
  margin: 20px 0 0;
  max-width: 44ch;
  font-size: clamp(15px, 1.6vw, 17px);
  line-height: 1.9;
  color: var(--ab-body-text);
}

.page-about .ab-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 26px;
}

.page-about .ab-hero__figure {
  margin: 0;
  position: relative;
  border: 1px solid var(--ab-hairline);
  padding: 10px;
  background: rgba(6, 31, 25, 0.6);
}

.page-about .ab-hero__figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  filter: saturate(0.85) brightness(0.82);
}

.page-about .ab-hero__caption {
  margin-top: 10px;
  font-size: 12px;
  line-height: 1.6;
  letter-spacing: 0.06em;
  color: var(--grey);
}

/* ---------- 数字带 ---------- */
.page-about .ab-stats-band {
  margin-top: clamp(26px, 4vw, 46px);
}

.page-about .ab-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--grid);
  border: 1px solid var(--grid);
}

.page-about .ab-stat {
  background: var(--ink-900);
  padding: 16px 14px 18px;
}

.page-about .ab-stat__value {
  margin: 0;
  font-family: var(--font-mono);
  font-size: clamp(26px, 4.2vw, 38px);
  line-height: 1;
  letter-spacing: -0.01em;
  color: var(--lime);
}

.page-about .ab-stat__label {
  margin: 8px 0 0;
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--grey);
}

/* ---------- 主体与左侧索引 ---------- */
.page-about .ab-body {
  padding-top: clamp(34px, 5.5vw, 76px);
}

.page-about .ab-layout {
  display: grid;
  gap: clamp(24px, 4vw, 56px);
}

.page-about .ab-index {
  border-top: 1px solid var(--ab-hairline);
  padding-top: 14px;
}

.page-about .ab-index__label {
  margin: 0 0 10px;
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--teal);
}

.page-about .ab-index__list {
  display: flex;
  gap: 8px;
  margin: 0;
  padding: 0 0 6px;
  list-style: none;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  scrollbar-width: thin;
}

.page-about .ab-index__link {
  display: flex;
  align-items: baseline;
  gap: 8px;
  padding: 8px 12px;
  border: 1px solid var(--grid);
  color: var(--grey);
  font-size: 13px;
  line-height: 1.4;
  text-decoration: none;
  white-space: nowrap;
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease), background-color var(--dur) var(--ease);
}

.page-about .ab-index__link:hover,
.page-about .ab-index__link:focus-visible {
  color: var(--cream);
  border-color: var(--orange);
  background: var(--ink-700);
  outline: none;
}

.page-about .ab-index__link:focus-visible {
  box-shadow: 0 0 0 2px rgba(255, 122, 33, 0.55);
}

.page-about .ab-index__num {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--teal);
  transition: color var(--dur) var(--ease);
}

.page-about .ab-index__link:hover .ab-index__num,
.page-about .ab-index__link:focus-visible .ab-index__num {
  color: var(--lime);
}

/* ---------- 章节 ---------- */
.page-about .ab-chapters {
  display: grid;
  gap: clamp(34px, 5vw, 72px);
}

.page-about .ab-chapter {
  position: relative;
  padding-top: clamp(26px, 3.4vw, 40px);
  border-top: 1px solid var(--ab-hairline);
}

.page-about .ab-chapter::before {
  content: "";
  position: absolute;
  top: -1px;
  left: 0;
  width: 72px;
  height: 3px;
  background: var(--lime);
}

.page-about .ab-chapter:nth-child(even)::before {
  background: var(--orange);
  width: 44px;
}

.page-about .section-head {
  display: grid;
  gap: 6px;
  margin-bottom: 20px;
}

.page-about .section__index {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--teal);
}

.page-about .section__title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 300;
  font-size: clamp(25px, 3.6vw, 40px);
  line-height: 1.12;
  letter-spacing: -0.015em;
  color: var(--cream);
  max-width: 22ch;
}

.page-about .ab-prose p {
  margin: 0 0 1.1em;
  max-width: 60ch;
  font-size: 15px;
  line-height: 1.9;
  color: var(--ab-body-text);
}

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

.page-about .ab-lede {
  margin: 0 0 18px;
  max-width: 56ch;
  font-size: clamp(15px, 1.6vw, 17px);
  line-height: 1.9;
  color: var(--cream);
}

.page-about .ab-lede--wide {
  max-width: 60ch;
}

.page-about .ab-note {
  margin: 18px 0 0;
  max-width: 62ch;
  font-size: 14px;
  line-height: 1.85;
  color: var(--grey);
}

.page-about .ab-note a {
  color: var(--lime);
  text-decoration: none;
  border-bottom: 1px solid rgba(200, 255, 69, 0.4);
  transition: border-color var(--dur) var(--ease);
}

.page-about .ab-note a:hover,
.page-about .ab-note a:focus-visible {
  border-bottom-color: var(--lime);
}

/* ---------- 01 起源 ---------- */
.page-about .ab-origin {
  display: grid;
  gap: clamp(18px, 3vw, 30px);
}

.page-about .ab-quote {
  margin: 0;
  padding: 6px 0 6px 18px;
  border-left: 2px solid var(--lime);
}

.page-about .ab-quote p {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 300;
  font-size: clamp(19px, 2.4vw, 26px);
  line-height: 1.45;
  color: var(--cream);
}

/* ---------- 02 覆盖 ---------- */
.page-about .ab-cover-grid {
  display: grid;
  gap: clamp(20px, 3vw, 32px);
}

.page-about .ab-cover-figure {
  margin: 0;
  border: 1px solid var(--ab-hairline);
  padding: 10px;
  background: rgba(10, 13, 12, 0.5);
}

.page-about .ab-cover-figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 5 / 6;
  object-fit: cover;
  filter: saturate(0.85) brightness(0.8);
}

.page-about .ab-cover-figure figcaption {
  margin-top: 10px;
  font-size: 12px;
  line-height: 1.6;
  color: var(--grey);
}

.page-about .ab-specs {
  margin: 0;
  border-top: 1px solid var(--ab-hairline);
}

.page-about .ab-specs__row {
  display: grid;
  gap: 4px;
  padding: 12px 0;
  border-bottom: 1px solid var(--ab-hairline);
}

.page-about .ab-specs__row dt {
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--teal);
}

.page-about .ab-specs__row dd {
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--ab-body-text);
}

/* ---------- 03 流程 ---------- */
.page-about .ab-flow-grid {
  display: grid;
  gap: clamp(20px, 3vw, 34px);
}

.page-about .ab-flow-figure {
  margin: 0;
  border: 1px solid var(--ab-hairline);
  padding: 10px;
  background: rgba(10, 13, 12, 0.5);
}

.page-about .ab-flow-figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 3 / 2;
  object-fit: cover;
  filter: saturate(0.8) brightness(0.78);
}

.page-about .ab-flow-figure figcaption {
  margin-top: 10px;
  font-size: 12px;
  line-height: 1.6;
  color: var(--grey);
}

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

.page-about .ab-step {
  display: grid;
  grid-template-columns: 1fr;
  gap: 6px;
  padding: 14px 0;
  border-bottom: 1px solid var(--ab-hairline);
}

.page-about .ab-step__num {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--orange);
}

.page-about .ab-step__title {
  margin: 0 0 4px;
  font-size: 16px;
  font-weight: 500;
  color: var(--cream);
}

.page-about .ab-step__body p {
  margin: 0;
  font-size: 14px;
  line-height: 1.85;
  color: var(--ab-body-text);
}

/* ---------- 04 时间线 ---------- */
.page-about .ab-tl {
  margin: 8px 0 0;
  padding: 0 0 0 20px;
  list-style: none;
  border-left: 1px solid var(--ab-hairline);
}

.page-about .ab-tl__item {
  position: relative;
  padding: 0 0 22px;
}

.page-about .ab-tl__item:last-child {
  padding-bottom: 0;
}

.page-about .ab-tl__item::before {
  content: "";
  position: absolute;
  top: 7px;
  left: -25px;
  width: 9px;
  height: 9px;
  background: var(--ink-900);
  border: 1px solid var(--lime);
  transition: background-color var(--dur) var(--ease), transform var(--dur) var(--ease);
}

.page-about .ab-tl__item:hover::before {
  background: var(--lime);
  transform: scale(1.25);
}

.page-about .ab-tl__ver {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--lime);
}

.page-about .ab-tl__title {
  margin: 5px 0 0;
  font-family: var(--font-display);
  font-weight: 400;
  font-size: clamp(17px, 2vw, 21px);
  line-height: 1.3;
  color: var(--cream);
}

.page-about .ab-tl__note {
  margin: 6px 0 0;
  max-width: 58ch;
  font-size: 14px;
  line-height: 1.85;
  color: var(--grey);
  transition: color var(--dur) var(--ease);
}

.page-about .ab-tl__item:hover .ab-tl__note {
  color: var(--cream);
}

/* ---------- 05 团队 ---------- */
.page-about .ab-team {
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .ab-team__item {
  display: grid;
  gap: 6px;
  padding: 20px 0;
  border-top: 1px solid var(--ab-hairline);
}

.page-about .ab-team__item:last-child {
  border-bottom: 1px solid var(--ab-hairline);
}

.page-about .ab-team__idx {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--teal);
}

.page-about .ab-team__name {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 400;
  font-size: clamp(18px, 2.2vw, 23px);
  line-height: 1.25;
  color: var(--cream);
}

.page-about .ab-team__desc {
  margin: 0;
  font-size: 14px;
  line-height: 1.85;
  color: var(--ab-body-text);
}

/* ---------- 06 合作 ---------- */
.page-about .ab-partner-groups {
  display: grid;
  gap: 14px;
}

.page-about .ab-panel {
  border: 1px solid var(--ab-hairline);
  padding: 16px 16px 18px;
  background: rgba(15, 53, 42, 0.35);
  transition: border-color var(--dur) var(--ease), transform var(--dur) var(--ease);
}

.page-about .ab-panel:hover {
  border-color: var(--orange);
  transform: translateY(-2px);
}

.page-about .ab-panel__title {
  margin: 0 0 8px;
  font-size: 16px;
  font-weight: 500;
  color: var(--cream);
}

.page-about .ab-panel__desc {
  margin: 0 0 12px;
  font-size: 14px;
  line-height: 1.85;
  color: var(--ab-body-text);
}

.page-about .ab-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .ab-tags .tag {
  border: 1px solid var(--grid);
  padding: 4px 10px;
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--lime);
  background: rgba(6, 31, 25, 0.6);
}

/* ---------- 07 做法与收尾 ---------- */
.page-about .ab-principles {
  display: grid;
  gap: 16px;
}

.page-about .ab-principle {
  border-left: 2px solid var(--grid);
  padding: 4px 0 4px 16px;
  transition: border-color var(--dur) var(--ease);
}

.page-about .ab-principle:hover {
  border-left-color: var(--lime);
}

.page-about .ab-principle__title {
  margin: 0 0 6px;
  font-size: 16px;
  font-weight: 500;
  color: var(--cream);
}

.page-about .ab-principle p {
  margin: 0;
  max-width: 46ch;
  font-size: 14px;
  line-height: 1.85;
  color: var(--ab-body-text);
}

.page-about .ab-principle a {
  color: var(--lime);
  text-decoration: none;
  border-bottom: 1px solid rgba(200, 255, 69, 0.4);
}

.page-about .ab-principle a:hover,
.page-about .ab-principle a:focus-visible {
  border-bottom-color: var(--lime);
}

.page-about .ab-cta {
  margin-top: clamp(22px, 3vw, 34px);
  padding: clamp(18px, 2.6vw, 26px);
  border: 1px solid var(--ab-hairline);
  background:
    linear-gradient(120deg, rgba(30, 106, 90, 0.32) 0%, rgba(10, 13, 12, 0.1) 62%),
    rgba(10, 13, 12, 0.6);
  display: grid;
  gap: 16px;
}

.page-about .ab-cta__text {
  margin: 0;
  max-width: 46ch;
  font-size: 15px;
  line-height: 1.85;
  color: var(--cream);
}

.page-about .ab-cta__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

/* ---------- 响应式 ---------- */
@media (min-width: 640px) {
  .page-about .ab-stats {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .ab-specs__row {
    grid-template-columns: 120px minmax(0, 1fr);
    gap: 16px;
    align-items: baseline;
  }

  .page-about .ab-step {
    grid-template-columns: 76px minmax(0, 1fr);
    gap: 14px;
  }

  .page-about .ab-team__item {
    grid-template-columns: 34px minmax(0, 3fr) minmax(0, 6fr);
    gap: 16px;
    align-items: baseline;
  }

  .page-about .ab-principles {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 20px 28px;
  }

  .page-about .ab-partner-groups {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

@media (min-width: 900px) {
  .page-about .ab-hero__grid {
    grid-template-columns: minmax(0, 6fr) minmax(0, 5fr);
    align-items: end;
  }

  .page-about .ab-stats {
    grid-template-columns: repeat(5, minmax(0, 1fr));
  }

  .page-about .ab-origin {
    grid-template-columns: minmax(0, 7fr) minmax(0, 4fr);
    align-items: start;
    gap: 40px;
  }

  .page-about .ab-cover-grid {
    grid-template-columns: minmax(0, 4fr) minmax(0, 7fr);
    align-items: start;
  }

  .page-about .ab-flow-grid {
    grid-template-columns: minmax(0, 5fr) minmax(0, 6fr);
    align-items: start;
  }

  .page-about .ab-cta {
    grid-template-columns: minmax(0, 7fr) auto;
    align-items: center;
  }
}

@media (min-width: 1000px) {
  .page-about .ab-layout {
    grid-template-columns: 210px minmax(0, 1fr);
    align-items: start;
    gap: 56px;
  }

  .page-about .ab-index {
    position: sticky;
    top: 104px;
  }

  .page-about .ab-index__list {
    flex-direction: column;
    gap: 2px;
    overflow: visible;
    padding-bottom: 0;
  }

  .page-about .ab-index__link {
    border-color: transparent;
    border-left: 2px solid transparent;
    padding: 9px 10px;
    white-space: normal;
  }

  .page-about .ab-index__link:hover,
  .page-about .ab-index__link:focus-visible {
    border-color: transparent;
    border-left-color: var(--orange);
    background: rgba(15, 53, 42, 0.55);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .ab-panel:hover {
    transform: none;
  }

  .page-about .ab-tl__item:hover::before {
    transform: none;
  }
}
<<<END>>>