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

.page-about section[id] {
  scroll-margin-top: 96px;
}

.page-about .h1,
.page-about .h2,
.page-about .h3 {
  color: var(--paper);
}

.page-about .ab-head {
  max-width: 48em;
  margin: 0 0 30px;
}

.page-about .ab-head__num {
  display: inline-block;
  margin: 0 0 14px;
  padding: 4px 10px;
  border: 2px solid var(--gold);
  border-radius: var(--radius);
  color: var(--gold);
  background: rgba(201, 162, 39, .08);
  font-size: 12px;
  letter-spacing: .14em;
}

.page-about .ab-head .h2 {
  margin: 0 0 12px;
}

.page-about .ab-head__sub {
  margin: 0;
  font-size: 15px;
  line-height: 1.85;
  color: rgba(244, 241, 232, .78);
}

/* ---------- 图片容器 ---------- */
.page-about .ab-fig {
  margin: 0;
  border: 2px solid var(--gold);
  border-radius: var(--radius);
  box-shadow: var(--shadow-hard);
  background: var(--ink);
  overflow: hidden;
}

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

.page-about .ab-fig__cap {
  padding: 10px 14px;
  border-top: 2px solid var(--line-gold);
  background: var(--green);
  color: var(--gold-soft);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .08em;
}

/* ---------- 首屏 ---------- */
.page-about .ab-hero {
  position: relative;
  padding: 26px 0 0;
  border-bottom: 2px solid var(--gold);
  background:
    radial-gradient(120% 90% at 82% 0%, rgba(53, 224, 208, .15) 0%, rgba(53, 224, 208, 0) 58%),
    linear-gradient(180deg, var(--ink) 0%, var(--green) 76%, var(--ink) 100%);
}

.page-about .ab-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image:
    linear-gradient(rgba(201, 162, 39, .07) 1px, transparent 1px),
    linear-gradient(90deg, rgba(201, 162, 39, .07) 1px, transparent 1px);
  background-size: 46px 46px;
  -webkit-mask-image: linear-gradient(180deg, #000 0%, transparent 88%);
  mask-image: linear-gradient(180deg, #000 0%, transparent 88%);
}

.page-about .ab-hero .wrap {
  position: relative;
  z-index: 1;
}

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

.page-about .crumb ol {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  margin: 0;
  padding: 0;
  list-style: none;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--gold-soft);
}

.page-about .crumb a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(53, 224, 208, .42);
}

.page-about .crumb li[aria-current="page"] {
  color: var(--gold-soft);
}

.page-about .crumb li + li::before {
  content: "/";
  margin-right: 8px;
  color: var(--line-gold);
}

.page-about .ab-hero__kicker {
  margin: 0 0 14px;
  color: var(--gold);
  font-size: 12px;
  letter-spacing: .16em;
  text-transform: uppercase;
}

.page-about .ab-hero__title {
  margin: 0 0 18px;
  max-width: 14em;
  font-size: clamp(30px, 8.4vw, 58px);
  text-shadow: 5px 5px 0 rgba(0, 0, 0, .52);
}

.page-about .ab-hero__lead {
  max-width: 34em;
  margin: 0 0 24px;
  color: var(--paper);
  font-size: 16px;
  line-height: 1.85;
}

.page-about .ab-hero__meta {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin: 0 0 30px;
}

.page-about .ab-jump {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  margin: 0;
  padding: 0;
  list-style: none;
  border-top: 2px solid var(--line-gold);
  border-left: 2px solid var(--line-gold);
}

.page-about .ab-jump li {
  min-width: 0;
  border-right: 2px solid var(--line-gold);
  border-bottom: 2px solid var(--line-gold);
}

.page-about .ab-jump a {
  display: flex;
  align-items: baseline;
  gap: 9px;
  height: 100%;
  padding: 13px 14px;
  color: var(--paper);
  text-decoration: none;
  font-size: 14px;
  transition: background .24s var(--ease), color .24s var(--ease);
}

.page-about .ab-jump a:hover,
.page-about .ab-jump a:focus-visible {
  background: var(--deep);
  color: var(--cyan);
}

.page-about .ab-jump .mono {
  color: var(--gold);
  font-size: 12px;
  letter-spacing: .1em;
}

/* ---------- 时间线 ---------- */
.page-about .ab-tl {
  padding: 56px 0 62px;
  border-top: 2px solid var(--gold);
  background: var(--deep);
}

.page-about .ab-tl .ab-fig--wide {
  margin-bottom: 34px;
}

.page-about .ab-tl__body {
  display: grid;
  gap: 0;
}

.page-about .ab-tl__rail {
  display: none;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .ab-tl__list {
  display: grid;
  gap: 18px;
  margin: 0;
  padding: 0;
  list-style: none;
  min-width: 0;
}

.page-about .ab-tl__item {
  position: relative;
  padding: 22px 20px 24px 26px;
  border: 2px solid var(--line-gold);
  border-radius: var(--radius);
  background: var(--green);
  box-shadow: var(--shadow-soft);
}

.page-about .ab-tl__item::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  width: 4px;
  height: 100%;
  background: var(--gold);
}

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

.page-about .ab-tl__item h3 {
  margin: 0 0 10px;
}

.page-about .ab-tl__item p {
  margin: 0 0 14px;
  color: rgba(244, 241, 232, .82);
  font-size: 15px;
  line-height: 1.85;
}

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

.page-about .ab-tl__tags li {
  padding: 4px 10px;
  border: 1px solid var(--line-soft);
  border-radius: var(--radius);
  color: var(--gold-soft);
  font-size: 11px;
  letter-spacing: .08em;
}

/* ---------- 三个难题 ---------- */
.page-about .ab-prob {
  padding: 54px 0 60px;
  border-top: 2px solid var(--gold);
  border-bottom: 2px solid var(--gold);
  background:
    radial-gradient(90% 70% at 12% 0%, rgba(201, 162, 39, .16) 0%, rgba(201, 162, 39, 0) 62%),
    var(--wine);
}

.page-about .ab-prob__grid {
  display: grid;
  gap: 18px;
}

.page-about .ab-prob__card {
  position: relative;
  overflow: hidden;
  padding: 26px 20px 24px;
  border: 2px solid var(--gold);
  border-radius: var(--radius);
  background: rgba(7, 19, 15, .52);
  box-shadow: var(--shadow-hard);
}

.page-about .ab-prob__card::after {
  content: "";
  position: absolute;
  top: 0;
  right: 0;
  width: 24px;
  height: 24px;
  background: var(--gold);
  clip-path: polygon(100% 0, 0 0, 100% 100%);
}

.page-about .ab-prob__no {
  margin: 0 0 10px;
  color: var(--gold-soft);
  font-size: 12px;
  letter-spacing: .14em;
}

.page-about .ab-prob__card h3 {
  margin: 0 0 12px;
}

.page-about .ab-prob__card p {
  margin: 0 0 12px;
  color: rgba(244, 241, 232, .84);
  font-size: 15px;
  line-height: 1.85;
}

.page-about .ab-prob__fix {
  display: flex;
  align-items: baseline;
  gap: 8px;
  margin: 0;
  padding-top: 12px;
  border-top: 1px solid var(--line-soft);
  color: var(--cyan) !important;
  font-size: 13px;
}

.page-about .ab-prob__fix .mono {
  color: var(--gold);
  font-size: 11px;
  letter-spacing: .12em;
}

/* ---------- 内容方法论 ---------- */
.page-about .ab-method {
  padding: 54px 0 60px;
  background: var(--paper);
  color: var(--ink);
}

.page-about .ab-method .h2,
.page-about .ab-method .h3 {
  color: var(--ink);
}

.page-about .ab-method .ab-head__num {
  border-color: var(--wine);
  color: var(--wine);
  background: rgba(110, 31, 50, .07);
}

.page-about .ab-method .ab-head__sub {
  color: rgba(14, 43, 37, .8);
}

.page-about .ab-m__rows {
  display: grid;
  gap: 0;
  border-top: 2px solid var(--ink);
}

.page-about .ab-m__row {
  padding: 24px 2px 26px;
  border-bottom: 2px solid var(--ink);
}

.page-about .ab-m__row:last-child {
  border-bottom: none;
}

.page-about .ab-m__num {
  margin: 0 0 10px;
  color: var(--wine);
  font-size: 12px;
  letter-spacing: .14em;
}

.page-about .ab-m__row h3 {
  margin: 0 0 10px;
}

.page-about .ab-m__row p {
  margin: 0;
  color: rgba(14, 43, 37, .84);
  font-size: 15px;
  line-height: 1.85;
}

/* ---------- 团队与产能 ---------- */
.page-about .ab-team {
  padding: 54px 0 60px;
  border-top: 2px solid var(--gold);
  background: var(--purple);
}

.page-about .ab-team__wrap {
  display: grid;
  gap: 24px;
  min-width: 0;
}

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

.page-about .ab-unit {
  margin-bottom: 12px;
  border: 2px solid var(--gold);
  border-radius: var(--radius);
  background: rgba(7, 19, 15, .38);
  box-shadow: var(--shadow-soft);
}

.page-about .ab-unit summary {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 14px 16px;
  cursor: pointer;
  list-style: none;
}

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

.page-about .ab-unit summary:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: -2px;
}

.page-about .ab-unit__num {
  min-width: 2.2em;
  color: var(--gold);
  font-family: var(--font-mono);
  font-size: 26px;
  font-weight: 700;
  line-height: 1;
  letter-spacing: .04em;
}

.page-about .ab-unit__role {
  color: var(--paper);
  font-size: 16px;
  font-weight: 700;
}

.page-about .ab-unit__hint {
  margin-left: auto;
  color: var(--cyan);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .1em;
  white-space: nowrap;
}

.page-about .ab-unit__hint::after {
  content: "+ 职责";
}

.page-about .ab-unit[open] .ab-unit__hint::after {
  content: "− 收起";
}

.page-about .ab-unit__body {
  margin: 0;
  padding: 0 16px 16px;
  color: rgba(244, 241, 232, .82);
  font-size: 14px;
  line-height: 1.8;
}

.page-about .ab-team__total {
  margin: 18px 0 0;
  padding-top: 14px;
  border-top: 1px solid var(--line-soft);
  color: var(--gold-soft);
  font-size: 12px;
  letter-spacing: .1em;
}

/* ---------- 共建伙伴 ---------- */
.page-about .ab-partner {
  padding: 54px 0 60px;
  border-top: 2px solid var(--gold);
  background: var(--deep);
}

.page-about .ab-partner__wrap {
  display: grid;
  gap: 26px;
  min-width: 0;
}

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

.page-about .ab-partner__stats {
  margin: 0 0 22px;
  padding: 0;
  list-style: none;
  border-top: 2px solid var(--line-gold);
}

.page-about .ab-partner__stats li {
  display: flex;
  align-items: baseline;
  gap: 14px;
  padding: 16px 4px;
  border-bottom: 2px solid var(--line-gold);
}

.page-about .ab-partner__num {
  min-width: 4.2em;
  color: var(--cyan);
  font-size: 26px;
  font-weight: 700;
  line-height: 1;
  letter-spacing: .04em;
}

.page-about .ab-partner__key {
  color: rgba(244, 241, 232, .86);
  font-size: 14px;
  line-height: 1.75;
}

.page-about .ab-partner__note {
  margin: 0;
  color: rgba(244, 241, 232, .8);
  font-size: 14px;
  line-height: 1.85;
}

.page-about .ab-link {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(53, 224, 208, .55);
}

/* ---------- 承诺 ---------- */
.page-about .ab-promise {
  padding: 56px 0 62px;
  border-top: 2px solid var(--gold);
  background: var(--ink);
}

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

.page-about .ab-badge {
  padding: 26px 18px 24px;
  border: 2px solid var(--gold);
  border-radius: var(--radius);
  background: var(--green);
  box-shadow: var(--shadow-hard);
  text-align: center;
}

.page-about .ab-badge__tag {
  display: inline-block;
  margin: 0 0 14px;
  padding: 3px 10px;
  border: 2px solid var(--cyan);
  border-radius: var(--radius);
  color: var(--cyan);
  font-size: 12px;
  letter-spacing: .16em;
}

.page-about .ab-badge__title {
  margin: 0 0 10px;
  color: var(--gold-soft);
  font-size: 20px;
  font-weight: 900;
  letter-spacing: .04em;
}

.page-about .ab-badge__text {
  margin: 0;
  color: rgba(244, 241, 232, .82);
  font-size: 14px;
  line-height: 1.8;
}

/* ---------- 继续浏览 ---------- */
.page-about .ab-next {
  padding: 34px 0 44px;
  border-top: 2px solid var(--gold);
  background: var(--green);
}

.page-about .ab-next__label {
  margin: 0 0 16px;
  color: var(--gold);
  font-size: 12px;
  letter-spacing: .14em;
}

.page-about .ab-next__list {
  display: grid;
  gap: 10px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .ab-next__list a {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: 14px 16px;
  border: 2px solid var(--line-gold);
  border-radius: var(--radius);
  color: var(--paper);
  text-decoration: none;
  font-size: 15px;
  font-weight: 700;
  transition: border-color .24s var(--ease), transform .24s var(--ease), color .24s var(--ease);
}

.page-about .ab-next__list a .mono {
  color: var(--gold-soft);
  font-size: 11px;
  font-weight: 400;
  letter-spacing: .1em;
}

.page-about .ab-next__list a:hover,
.page-about .ab-next__list a:focus-visible {
  border-color: var(--cyan);
  color: var(--cyan);
  transform: translate(-2px, -2px);
}

/* ---------- 滚动显现（纯 CSS，降级安全） ---------- */
@keyframes ab-rise {
  from {
    opacity: 0;
    transform: translateY(14px);
  }
  to {
    opacity: 1;
    transform: none;
  }
}

@supports (animation-timeline: view()) {
  @media (prefers-reduced-motion: no-preference) {
    .page-about .ab-tl__item,
    .page-about .ab-prob__card,
    .page-about .ab-badge {
      animation: ab-rise linear both;
      animation-timeline: view();
      animation-range: entry 0% entry 62%;
    }

    .page-about .ab-tl__item:nth-child(2) {
      animation-delay: .06s;
    }

    .page-about .ab-tl__item:nth-child(3) {
      animation-delay: .12s;
    }

    .page-about .ab-tl__item:nth-child(4) {
      animation-delay: .18s;
    }
  }
}

/* ---------- 响应式 ---------- */
@media (min-width: 720px) {
  .page-about .ab-jump {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

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

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

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

  .page-about .ab-m__rows {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    border-bottom: 2px solid var(--ink);
  }

  .page-about .ab-m__row {
    padding: 26px 22px 30px;
    border-bottom: none;
    border-right: 2px solid var(--ink);
  }

  .page-about .ab-m__row:last-child {
    border-right: none;
  }
}

@media (min-width: 880px) {
  .page-about .ab-hero {
    padding-top: 34px;
  }

  .page-about .ab-tl__body {
    grid-template-columns: 88px minmax(0, 1fr);
    gap: 0 36px;
  }

  .page-about .ab-tl__rail {
    display: block;
    position: sticky;
    top: 104px;
    align-self: start;
    padding-left: 16px;
    border-left: 2px solid var(--line-gold);
  }

  .page-about .ab-tl__rail-item {
    position: relative;
    padding: 9px 0;
    color: rgba(240, 217, 140, .5);
    font-family: var(--font-mono);
    font-size: 13px;
    letter-spacing: .12em;
  }

  .page-about .ab-tl__rail-item::before {
    content: "";
    position: absolute;
    left: -21px;
    top: 50%;
    width: 8px;
    height: 8px;
    transform: translateY(-50%);
    border: 2px solid var(--line-gold);
    border-radius: 50%;
    background: var(--deep);
  }

  .page-about .ab-tl__rail-item.is-on {
    color: var(--cyan);
  }

  .page-about .ab-tl__rail-item.is-on::before {
    border-color: var(--cyan);
    background: var(--cyan);
    box-shadow: 0 0 10px rgba(53, 224, 208, .8);
  }

  .page-about .ab-tl__list {
    gap: 22px;
  }

  .page-about .ab-team__wrap {
    grid-template-columns: 0.88fr 1.12fr;
    gap: 32px;
    align-items: start;
  }

  .page-about .ab-partner__wrap {
    grid-template-columns: 1fr 1fr;
    gap: 34px;
    align-items: center;
  }

  .page-about .ab-next__list {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

@media (min-width: 1080px) {
  .page-about .ab-hero__lead {
    font-size: 17px;
  }

  .page-about .ab-tl,
  .page-about .ab-prob,
  .page-about .ab-method,
  .page-about .ab-team,
  .page-about .ab-partner,
  .page-about .ab-promise {
    padding-top: 68px;
    padding-bottom: 74px;
  }
}