.page-about {
  background: var(--ink-900);
  color: var(--white);
  font-family: var(--font-sans);
  overflow-x: hidden;
}

.page-about *,
.page-about *::before,
.page-about *::after {
  box-sizing: border-box;
}

.page-about .ab-in {
  width: 100%;
  max-width: var(--maxw);
  margin-inline: auto;
  padding-inline: var(--pad-x);
}

/* ---------- 首屏 ---------- */
.page-about .ab-hero {
  position: relative;
  padding-block: clamp(22px, 4vw, 44px) clamp(38px, 6vw, 84px);
  border-bottom: 1px solid var(--line);
  background:
    radial-gradient(120% 90% at 88% 0%, rgba(45, 226, 230, 0.14), transparent 62%),
    radial-gradient(90% 70% at 0% 100%, rgba(255, 107, 53, 0.12), transparent 66%),
    var(--ink-900);
  isolation: isolate;
}

.page-about .ab-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  background-image:
    linear-gradient(to right, rgba(169, 183, 198, 0.07) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(169, 183, 198, 0.07) 1px, transparent 1px);
  background-size: 64px 64px;
  pointer-events: none;
}

.page-about .ab-crumbs {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.09em;
  color: var(--mist);
}

.page-about .ab-crumbs a {
  color: var(--cyan);
  text-decoration: none;
}

.page-about .ab-crumbs a:hover,
.page-about .ab-crumbs a:focus-visible {
  text-decoration: underline;
}

.page-about .ab-hero__grid {
  position: relative;
  display: grid;
  gap: clamp(26px, 4vw, 46px);
  margin-top: clamp(20px, 3vw, 34px);
}

.page-about .ab-kicker {
  margin: 0 0 14px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--cyan);
}

.page-about .ab-kicker--paper {
  color: #b33a12;
}

.page-about .ab-title {
  margin: 0;
  font-size: clamp(32px, 6.2vw, 76px);
  line-height: 1.04;
  letter-spacing: -0.02em;
  font-weight: 800;
  color: var(--white);
  max-width: 18ch;
}

.page-about .ab-lede {
  margin: 20px 0 0;
  max-width: 46ch;
  font-size: clamp(15px, 1.6vw, 18px);
  line-height: 1.85;
  color: rgba(247, 250, 252, 0.82);
}

/* 首屏档案卡 */
.page-about .ab-deck {
  display: grid;
  gap: 12px;
  align-content: end;
}

.page-about .ab-card {
  position: relative;
  display: grid;
  gap: 6px;
  padding: 16px 18px;
  background: linear-gradient(158deg, var(--panel), rgba(14, 42, 69, 0.5));
  border: 1px solid var(--line-strong);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 16px), calc(100% - 16px) 100%, 0 100%);
}

.page-about .ab-card__k {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--mist);
}

.page-about .ab-card__v {
  font-family: var(--font-mono);
  font-size: clamp(24px, 3.2vw, 34px);
  line-height: 1;
  font-weight: 700;
  color: var(--cyan);
}

.page-about .ab-card__s {
  font-size: 12px;
  color: var(--mist);
}

.page-about .ab-deck__pair {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
}

.page-about .ab-deck__note {
  display: flex;
  align-items: center;
  gap: 9px;
  margin: 2px 0 0;
  font-size: 12.5px;
  line-height: 1.6;
  color: var(--mist);
}

.page-about .ab-deck__note .dot {
  flex: none;
}

/* ---------- 章节索引条 ---------- */
.page-about .ab-index {
  background: var(--ink-800);
  border-bottom: 1px solid var(--line);
}

.page-about .ab-index__in {
  padding-inline: 0;
}

.page-about .ab-index__list {
  display: flex;
  margin: 0;
  padding: 0;
  list-style: none;
  overflow-x: auto;
  scrollbar-width: none;
}

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

.page-about .ab-index__link {
  display: flex;
  align-items: baseline;
  gap: 9px;
  padding: 15px 18px;
  border-right: 1px solid var(--line);
  font-size: 13.5px;
  white-space: nowrap;
  text-decoration: none;
  color: var(--mist);
  transition: color 0.2s var(--ease), background-color 0.2s var(--ease);
}

.page-about .ab-index__link:hover,
.page-about .ab-index__link:focus-visible {
  color: var(--white);
  background: var(--panel);
  box-shadow: inset 0 -2px 0 var(--cyan);
  outline: none;
}

.page-about .ab-index__i {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--cyan);
}

/* ---------- 章节通用 ---------- */
.page-about .ab-sec {
  padding-block: clamp(42px, 7vw, 92px);
  scroll-margin-top: 72px;
}

.page-about .ab-sec--deep {
  background: var(--ink-900);
}

.page-about .ab-sec--graphite {
  background: var(--ink-800);
}

.page-about .ab-sec--paper {
  background: var(--paper);
  color: var(--paper-ink);
  --line: var(--paper-line);
  --line-strong: rgba(43, 31, 23, 0.4);
  --mist: rgba(43, 31, 23, 0.62);
}

.page-about .ab-head {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: clamp(12px, 3vw, 30px);
  align-items: start;
  margin-bottom: clamp(24px, 4vw, 46px);
}

.page-about .ab-head__num {
  font-family: var(--font-mono);
  font-size: clamp(34px, 5.6vw, 76px);
  line-height: 0.86;
  font-weight: 700;
  color: var(--line-strong);
  -webkit-text-stroke: 1px var(--line-strong);
  color: transparent;
}

@supports not ((-webkit-text-stroke: 1px #000) or (text-stroke: 1px #000)) {
  .page-about .ab-head__num {
    color: var(--line-strong);
  }
}

.page-about .ab-head h2 {
  margin: 0;
  font-size: clamp(22px, 3.4vw, 40px);
  line-height: 1.2;
  letter-spacing: -0.01em;
  font-weight: 800;
}

.page-about .ab-prose {
  max-width: 62ch;
  font-size: clamp(15px, 1.5vw, 17px);
  line-height: 1.9;
}

.page-about .ab-prose p {
  margin: 0 0 1.05em;
}

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

/* ---------- 图片 ---------- */
.page-about .ab-fig {
  position: relative;
  margin: 0;
  border: 1px solid var(--line-strong);
  background: var(--panel);
}

.page-about .ab-fig--wide {
  margin-bottom: clamp(24px, 4vw, 44px);
}

.page-about .ab-fig img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
}

.page-about .ab-fig__cap {
  position: absolute;
  left: 0;
  bottom: 0;
  padding: 6px 11px;
  background: var(--ink-900);
  border-top: 1px solid var(--line-strong);
  border-right: 1px solid var(--line-strong);
  font-family: var(--font-mono);
  font-size: 10.5px;
  letter-spacing: 0.1em;
  color: var(--mist);
}

/* ---------- 01 品牌起点 ---------- */
.page-about .ab-origin {
  display: grid;
  gap: clamp(24px, 4vw, 50px);
}

/* ---------- 02 三条原则 ---------- */
.page-about .ab-rules {
  display: grid;
  border-top: 1px solid var(--paper-line);
}

.page-about .ab-rule {
  padding: 24px 0 26px;
  border-bottom: 1px solid var(--paper-line);
}

.page-about .ab-rule__i {
  display: block;
  margin-bottom: 10px;
  font-family: var(--font-mono);
  font-size: 10.5px;
  letter-spacing: 0.16em;
  color: #b33a12;
}

.page-about .ab-rule h3 {
  margin: 0 0 12px;
  font-size: clamp(18px, 2vw, 23px);
  line-height: 1.35;
  font-weight: 800;
  color: var(--paper-ink);
}

.page-about .ab-rule p {
  margin: 0;
  font-size: 15px;
  line-height: 1.85;
  color: rgba(43, 31, 23, 0.86);
}

/* ---------- 03 时间线 ---------- */
.page-about .ab-stages {
  border-top: 1px solid var(--line);
}

.page-about .ab-stage {
  border-bottom: 1px solid var(--line);
}

.page-about .ab-stage summary {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  gap: 12px;
  align-items: baseline;
  padding: 16px 0;
  cursor: pointer;
  list-style: none;
  transition: color 0.2s var(--ease);
}

.page-about .ab-stage summary::-webkit-details-marker {
  display: none;
}

.page-about .ab-stage summary:hover .ab-stage__t,
.page-about .ab-stage summary:focus-visible .ab-stage__t {
  color: var(--cyan);
}

.page-about .ab-stage summary:focus-visible {
  outline: 1px solid var(--cyan);
  outline-offset: 4px;
}

.page-about .ab-stage__n {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--cyan);
}

.page-about .ab-stage__t {
  font-size: clamp(15.5px, 1.8vw, 20px);
  font-weight: 700;
  line-height: 1.4;
  color: var(--white);
  transition: color 0.2s var(--ease);
}

.page-about .ab-stage[open] .ab-stage__t {
  color: var(--cyan);
}

.page-about .ab-stage__x {
  position: relative;
  width: 14px;
  height: 14px;
  flex: none;
  align-self: center;
}

.page-about .ab-stage__x::before,
.page-about .ab-stage__x::after {
  content: "";
  position: absolute;
  top: 50%;
  left: 0;
  width: 14px;
  height: 1px;
  background: var(--mist);
  transition: transform 0.25s var(--ease);
}

.page-about .ab-stage__x::after {
  transform: rotate(90deg);
}

.page-about .ab-stage[open] .ab-stage__x::after {
  transform: rotate(0deg);
}

.page-about .ab-stage__body {
  padding: 0 0 20px 32px;
  font-size: 14.5px;
  line-height: 1.85;
  color: rgba(247, 250, 252, 0.78);
}

.page-about .ab-stage__body p {
  margin: 0;
  max-width: 62ch;
}

/* ---------- 04 团队 ---------- */
.page-about .ab-team {
  display: grid;
  gap: clamp(24px, 4vw, 46px);
}

.page-about .ab-team .ab-fig {
  background: var(--ink-900);
}

.page-about .ab-facts {
  margin: clamp(26px, 4vw, 40px) 0 0;
  border-top: 1px solid var(--paper-line);
}

.page-about .ab-facts__row {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 4px;
  padding: 12px 0;
  border-bottom: 1px solid var(--paper-line);
}

.page-about .ab-facts__row dt {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  color: #b33a12;
}

.page-about .ab-facts__row dd {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.7;
  color: var(--paper-ink);
}

/* ---------- 05 合作生态 ---------- */
.page-about .ab-partners {
  display: grid;
  gap: clamp(26px, 4vw, 48px);
}

.page-about .ab-nums {
  display: grid;
  gap: 16px;
}

.page-about .ab-num {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 16px;
  align-items: baseline;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--line);
}

.page-about .ab-num strong {
  font-family: var(--font-mono);
  font-size: clamp(30px, 4.2vw, 46px);
  line-height: 1;
  font-weight: 700;
  color: var(--lava);
}

.page-about .ab-num span {
  font-size: 14px;
  line-height: 1.55;
  color: var(--white);
}

.page-about .ab-num em {
  font-style: normal;
  font-size: 12.5px;
  color: var(--mist);
}

.page-about .ab-partners__side .ab-prose {
  color: rgba(247, 250, 252, 0.82);
}

.page-about .ab-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 22px 0 0;
  padding: 0;
  list-style: none;
}

.page-about .ab-tag {
  padding: 7px 12px;
  border: 1px solid var(--line-strong);
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.06em;
  color: var(--mist);
  background: rgba(14, 42, 69, 0.5);
}

.page-about .ab-tag--cyan {
  border-color: rgba(45, 226, 230, 0.5);
  color: var(--cyan);
  background: var(--cyan-08);
}

.page-about .ab-tag--lava {
  border-color: rgba(255, 107, 53, 0.5);
  color: var(--lava);
  background: var(--lava-08);
}

/* ---------- 06 服务范围与联系 ---------- */
.page-about .ab-reach {
  display: grid;
  gap: clamp(22px, 3.4vw, 34px);
}

.page-about .ab-reach .ab-prose {
  color: rgba(247, 250, 252, 0.84);
}

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

/* ---------- 中屏与桌面 ---------- */
@media (min-width: 640px) {
  .page-about .ab-facts__row {
    grid-template-columns: minmax(0, 0.5fr) minmax(0, 1fr);
    gap: 20px;
    align-items: baseline;
  }

  .page-about .ab-deck__pair {
    gap: 14px;
  }
}

@media (min-width: 880px) {
  .page-about .ab-origin {
    grid-template-columns: minmax(0, 6fr) minmax(0, 5fr);
    align-items: center;
  }

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

  .page-about .ab-team .ab-fig {
    order: 2;
  }

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

  .page-about .ab-rule {
    padding: 26px 22px 30px;
    border-bottom: none;
    border-left: 1px solid var(--paper-line);
  }

  .page-about .ab-rule:first-child {
    padding-left: 0;
    border-left: none;
  }

  .page-about .ab-rule:last-child {
    padding-right: 0;
  }

  .page-about .ab-partners {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    align-items: start;
  }
}

@media (min-width: 980px) {
  .page-about .ab-hero__grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    align-items: end;
  }

  .page-about .ab-title {
    font-size: clamp(44px, 5.4vw, 76px);
  }

  .page-about .ab-index__in {
    padding-inline: var(--pad-x);
  }
}

@media (min-width: 1240px) {
  .page-about .ab-origin .ab-prose {
    padding-right: 24px;
  }

  .page-about .ab-stage summary {
    padding: 19px 0;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .ab-index__link,
  .page-about .ab-stage summary,
  .page-about .ab-stage__t,
  .page-about .ab-stage__x::before,
  .page-about .ab-stage__x::after {
    transition: none;
  }
}
<<<END>>>