.page-about {
  --ab-grid-line: rgba(11, 43, 38, .06);
  --ab-copper-soft: rgba(176, 122, 42, .16);
  background: var(--cream);
  color: var(--black);
}

.page-about .ab-wrap {
  width: 100%;
  max-width: var(--shell);
  margin-inline: auto;
  padding-inline: clamp(1.1rem, 4vw, 2.5rem);
}

.page-about .ab-narrow {
  max-width: 880px;
}

.page-about a:focus-visible {
  outline: 2px solid var(--orange);
  outline-offset: 3px;
}

/* ---------- 首屏 ---------- */
.page-about .ab-hero {
  position: relative;
  overflow: hidden;
  padding-block: clamp(1.4rem, 4vw, 2.4rem) clamp(2.2rem, 5vw, 3.6rem);
  background: linear-gradient(180deg, var(--paper) 0%, var(--cream) 100%);
  border-bottom: 1px solid var(--line);
}

.page-about .ab-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    repeating-linear-gradient(90deg, var(--ab-grid-line) 0 1px, transparent 1px 72px),
    repeating-linear-gradient(0deg, var(--ab-grid-line) 0 1px, transparent 1px 72px);
  -webkit-mask-image: linear-gradient(180deg, #000 0%, transparent 92%);
  mask-image: linear-gradient(180deg, #000 0%, transparent 92%);
  pointer-events: none;
}

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

.page-about .ab-hero .breadcrumb {
  margin-bottom: clamp(1.3rem, 4vw, 2.2rem);
  font-size: .82rem;
}

.page-about .ab-hero .breadcrumb-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: .4rem;
}

.page-about .ab-hero .breadcrumb-item {
  display: inline-flex;
  align-items: center;
  gap: .4rem;
}

.page-about .ab-hero .breadcrumb-link {
  color: var(--graphite);
  text-decoration: none;
}

.page-about .ab-hero .breadcrumb-link:hover {
  color: var(--copper-ink);
}

.page-about .ab-hero .breadcrumb-sep {
  color: var(--mist);
}

.page-about .ab-hero .breadcrumb-current {
  color: var(--ink-900);
  font-weight: 600;
}

.page-about .ab-hero-grid {
  display: grid;
  gap: 2rem;
}

.page-about .ab-stamp {
  display: inline-flex;
  align-items: center;
  gap: .55rem;
  margin: 0 0 1rem;
  padding: .32rem .72rem;
  border: 1px solid var(--copper);
  border-radius: 999px;
  font-size: .72rem;
  letter-spacing: .04em;
  color: var(--copper-ink);
  background: rgba(251, 248, 242, .72);
}

.page-about .ab-stamp-dot {
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--orange);
}

.page-about .ab-hero h1 {
  margin: .4rem 0 0;
  font-family: var(--font-head);
  font-weight: 900;
  font-size: clamp(1.95rem, 6vw, 3.4rem);
  line-height: 1.12;
  letter-spacing: -.01em;
  color: var(--ink-900);
}

.page-about .ab-lede {
  margin: 1.1rem 0 0;
  max-width: 46ch;
  font-size: clamp(.96rem, 1.7vw, 1.06rem);
  line-height: 1.72;
  color: var(--graphite);
}

.page-about .ab-lede-2 {
  margin: .95rem 0 0;
  max-width: 42ch;
  padding-left: .9rem;
  border-left: 2px solid var(--copper-300);
  font-size: .92rem;
  line-height: 1.7;
  color: var(--ink-700);
}

/* 页内索引 */
.page-about .ab-toc {
  position: relative;
  background: var(--paper);
  border: 1px solid var(--line-strong);
  border-radius: var(--radius-card);
  padding: 1.1rem 1.15rem 1rem;
  box-shadow: var(--shadow-card);
}

.page-about .ab-toc::after {
  content: "";
  position: absolute;
  top: -1px;
  right: 18px;
  width: 34px;
  height: 12px;
  border-radius: 0 0 3px 3px;
  background: var(--copper-300);
  opacity: .85;
}

.page-about .ab-toc-title {
  margin: 0 0 .55rem;
  font-size: .72rem;
  letter-spacing: .16em;
  color: var(--copper-ink);
}

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

.page-about .ab-toc-list li + li {
  border-top: 1px dashed var(--line);
}

.page-about .ab-toc-list a {
  display: flex;
  align-items: baseline;
  gap: .7rem;
  padding: .52rem .1rem;
  font-size: .9rem;
  color: var(--ink-900);
  text-decoration: none;
  transition: color .2s ease, transform .2s ease;
}

.page-about .ab-toc-list a:hover {
  color: var(--copper-ink);
  transform: translateX(3px);
}

.page-about .ab-toc-list .mono {
  font-size: .74rem;
  color: var(--copper);
}

/* ---------- 通用章节 ---------- */
.page-about .ab-section {
  padding-block: clamp(2.4rem, 6vw, 4.4rem);
}

.page-about .ab-section--paper {
  background: var(--paper);
  border-block: 1px solid var(--line);
}

.page-about .ab-section--dark {
  position: relative;
  overflow: hidden;
  background: var(--ink-900);
  color: var(--cream);
}

.page-about .ab-section--dark::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image: repeating-linear-gradient(90deg, rgba(175, 196, 186, .09) 0 1px, transparent 1px 88px);
  pointer-events: none;
}

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

.page-about .ab-sec-head {
  max-width: 62ch;
  margin-bottom: clamp(1.3rem, 3vw, 2.1rem);
}

.page-about .ab-sec-index {
  margin: 0 0 .5rem;
  font-size: .74rem;
  letter-spacing: .14em;
  color: var(--copper);
}

.page-about .ab-sec-head h2 {
  margin: 0;
  font-family: var(--font-head);
  font-weight: 800;
  font-size: clamp(1.42rem, 3.6vw, 2.1rem);
  line-height: 1.22;
  color: var(--ink-900);
}

.page-about .ab-sec-head p {
  margin: .8rem 0 0;
  line-height: 1.75;
  color: var(--graphite);
}

.page-about .ab-sec-head--light h2 {
  color: var(--cream);
}

.page-about .ab-sec-head--light p {
  color: var(--mist);
}

.page-about .ab-sec-head--light .ab-sec-index {
  color: var(--copper-300);
}

/* ---------- 图片 ---------- */
.page-about .ab-figure {
  margin: 0;
  overflow: hidden;
  border: 1px solid var(--line-strong);
  border-radius: var(--radius-card);
  background: var(--paper);
  box-shadow: var(--shadow-card);
}

.page-about .ab-figure img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  aspect-ratio: 16 / 10;
  object-fit: cover;
}

.page-about .ab-figure figcaption {
  padding: .6rem .85rem;
  border-top: 1px solid var(--line);
  background: var(--cream);
  font-size: .72rem;
  letter-spacing: .04em;
  color: var(--graphite);
}

.page-about .ab-figure--wide {
  margin-bottom: clamp(1.6rem, 4vw, 2.6rem);
}

/* ---------- 时间轴 ---------- */
.page-about .ab-tl {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .ab-tl-item {
  position: relative;
  padding: 0 0 clamp(1.6rem, 4vw, 2.3rem) 1.55rem;
  border-left: 1px solid var(--line-strong);
}

.page-about .ab-tl-item:last-child {
  padding-bottom: 0;
  border-left-color: transparent;
}

.page-about .ab-tl-item::before {
  content: "";
  position: absolute;
  left: -5.5px;
  top: .5rem;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--copper);
  box-shadow: 0 0 0 4px var(--cream);
}

.page-about .ab-tl-year {
  display: flex;
  align-items: baseline;
  gap: .55rem;
  margin-bottom: .35rem;
}

.page-about .ab-tl-y {
  font-family: var(--font-mono);
  font-size: 1.12rem;
  font-weight: 600;
  letter-spacing: .02em;
  color: var(--copper-ink);
}

.page-about .ab-tl-stage {
  padding: .1rem .5rem;
  border: 1px solid var(--line-strong);
  border-radius: 999px;
  font-size: .7rem;
  letter-spacing: .1em;
  color: var(--graphite);
}

.page-about .ab-tl-body h3 {
  margin: 0 0 .35rem;
  font-family: var(--font-head);
  font-weight: 700;
  font-size: clamp(1rem, 2.2vw, 1.18rem);
  color: var(--ink-900);
}

.page-about .ab-tl-body p {
  margin: 0;
  max-width: 60ch;
  line-height: 1.76;
  color: var(--graphite);
  font-size: .94rem;
}

/* ---------- 三步排查 ---------- */
.page-about .ab-steps {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: .9rem;
}

.page-about .ab-step {
  padding: 1.1rem 1.05rem 1.15rem;
  border: 1px solid rgba(217, 178, 124, .3);
  border-top: 3px solid var(--copper);
  border-radius: 8px;
  background: var(--ink-700);
}

.page-about .ab-step-num {
  display: block;
  margin-bottom: .7rem;
  font-size: 1.6rem;
  line-height: 1;
  color: var(--copper-300);
}

.page-about .ab-step h3 {
  margin: 0 0 .4rem;
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 1.05rem;
  color: var(--cream);
}

.page-about .ab-step p {
  margin: 0;
  font-size: .92rem;
  line-height: 1.72;
  color: var(--mist);
}

.page-about .ab-method-note {
  margin-top: clamp(1.3rem, 3vw, 2rem);
  padding-top: 1.1rem;
  border-top: 1px dashed rgba(217, 178, 124, .35);
  display: grid;
  gap: 1rem;
}

.page-about .ab-method-note p {
  margin: 0;
  max-width: 66ch;
  line-height: 1.78;
  color: var(--mist);
  font-size: .94rem;
}

.page-about .ab-textlink {
  display: inline-flex;
  align-items: center;
  gap: .4rem;
  padding-bottom: .15rem;
  border-bottom: 1px solid rgba(217, 178, 124, .5);
  color: var(--copper-300);
  font-weight: 700;
  font-size: .9rem;
  text-decoration: none;
  white-space: nowrap;
  justify-self: start;
  transition: color .2s ease, border-color .2s ease;
}

.page-about .ab-textlink:hover {
  color: var(--cream);
  border-color: var(--cream);
}

.page-about .ab-textlink--ink {
  color: var(--copper-ink);
  border-color: rgba(176, 122, 42, .45);
}

.page-about .ab-textlink--ink:hover {
  color: var(--ink-900);
  border-color: var(--ink-900);
}

.page-about .ab-inline-link {
  color: var(--copper-300);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.page-about .ab-inline-link:hover {
  color: var(--cream);
}

/* ---------- 团队 ---------- */
.page-about .ab-team-top {
  display: grid;
  gap: 1.6rem;
  margin-bottom: clamp(1.4rem, 3vw, 2.2rem);
}

.page-about .ab-team-cards {
  display: grid;
  gap: 1rem;
}

.page-about .ab-team-card {
  padding: 1.2rem 1.15rem 1.1rem;
  border: 1px solid var(--line-strong);
  border-radius: var(--radius-card);
  background: var(--paper);
  box-shadow: 5px 5px 0 var(--ab-copper-soft);
  transition: transform .25s ease, box-shadow .25s ease, border-color .25s ease;
}

.page-about .ab-team-card:hover,
.page-about .ab-team-card:focus-within {
  transform: translateY(-4px);
  border-color: var(--copper);
  box-shadow: 7px 9px 0 var(--ab-copper-soft);
}

.page-about .ab-team-role {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: .6rem;
  margin-bottom: .7rem;
  padding-bottom: .6rem;
  border-bottom: 1px solid var(--line);
}

.page-about .ab-team-role h3 {
  margin: 0;
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 1.08rem;
  color: var(--ink-900);
}

.page-about .ab-team-count {
  font-size: .8rem;
  color: var(--copper-ink);
}

.page-about .ab-team-card p {
  margin: 0;
  font-size: .93rem;
  line-height: 1.72;
  color: var(--graphite);
}

.page-about .ab-team-more {
  margin-top: .8rem !important;
  padding: .7rem .8rem;
  border-left: 2px solid var(--copper-300);
  background: var(--cream);
  font-size: .87rem !important;
  color: var(--ink-700) !important;
  opacity: .8;
  transition: opacity .25s ease, background .25s ease;
}

.page-about .ab-team-card:hover .ab-team-more,
.page-about .ab-team-card:focus-within .ab-team-more {
  opacity: 1;
  background: rgba(217, 178, 124, .18);
}

/* ---------- 质量 ---------- */
.page-about .ab-quality {
  position: relative;
}

.page-about .ab-seal {
  display: none;
}

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

.page-about .ab-qitem {
  display: grid;
  gap: .35rem;
  padding: 1.05rem .15rem;
  border-bottom: 1px solid var(--line);
}

.page-about .ab-qnum {
  font-size: .78rem;
  letter-spacing: .08em;
  color: var(--copper);
}

.page-about .ab-qitem h3 {
  margin: 0;
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 1rem;
  color: var(--ink-900);
}

.page-about .ab-qitem p {
  margin: 0;
  font-size: .93rem;
  line-height: 1.72;
  color: var(--graphite);
}

/* ---------- 区域 ---------- */
.page-about .ab-region-grid {
  display: grid;
  gap: 1.8rem;
}

.page-about .ab-region-grid h2 {
  margin: 0;
  font-family: var(--font-head);
  font-weight: 800;
  font-size: clamp(1.42rem, 3.4vw, 2.05rem);
  line-height: 1.22;
  color: var(--cream);
}

.page-about .ab-region-grid > div > p {
  margin: .8rem 0 0;
  line-height: 1.78;
  color: var(--mist);
  font-size: .94rem;
}

.page-about .ab-region-facts {
  list-style: none;
  margin: 1.2rem 0 0;
  padding: 0;
  display: grid;
  gap: .55rem;
}

.page-about .ab-region-facts li {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: .65rem;
  padding: .62rem .78rem;
  border: 1px solid rgba(217, 178, 124, .24);
  border-radius: 6px;
  background: rgba(11, 43, 38, .5);
  color: var(--cream);
  font-size: .9rem;
  line-height: 1.5;
}

.page-about .ab-region-facts .mono {
  font-size: .82rem;
  color: var(--copper-300);
}

.page-about .ab-region-note {
  margin: 1rem 0 0 !important;
  font-size: .88rem !important;
  line-height: 1.72;
  color: var(--mist);
}

/* ---------- 协作 ---------- */
.page-about .ab-tags {
  list-style: none;
  margin: 1.3rem 0 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: .5rem;
}

.page-about .ab-tag {
  padding: .38rem .82rem;
  border: 1px solid var(--line-strong);
  border-radius: 999px;
  background: var(--paper);
  font-size: .82rem;
  color: var(--ink-700);
}

/* ---------- 收束 ---------- */
.page-about .ab-cta {
  padding-block: clamp(2rem, 5vw, 3.4rem);
}

.page-about .ab-cta-inner {
  position: relative;
  overflow: hidden;
  display: grid;
  gap: 1.4rem;
  padding: clamp(1.4rem, 4vw, 2.4rem);
  border-top: 4px solid var(--copper);
  border-radius: var(--radius-card);
  background: var(--ink-900);
  color: var(--cream);
}

.page-about .ab-cta-kicker {
  margin: 0 0 .5rem;
  font-size: .72rem;
  letter-spacing: .16em;
  color: var(--copper-300);
}

.page-about .ab-cta-inner h2 {
  margin: 0;
  font-family: var(--font-head);
  font-weight: 800;
  font-size: clamp(1.24rem, 3vw, 1.68rem);
  line-height: 1.26;
  color: var(--cream);
}

.page-about .ab-cta-inner p {
  margin: .7rem 0 0;
  max-width: 54ch;
  font-size: .92rem;
  line-height: 1.74;
  color: var(--mist);
}

.page-about .ab-cta-actions {
  display: flex;
  flex-wrap: wrap;
  gap: .7rem;
}

.page-about .ab-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: .72rem 1.3rem;
  border: 1px solid transparent;
  border-radius: 999px;
  font-family: var(--font-body);
  font-size: .9rem;
  font-weight: 700;
  text-decoration: none;
  transition: background .2s ease, color .2s ease, border-color .2s ease, transform .2s ease;
}

.page-about .ab-btn--solid {
  background: var(--copper);
  color: var(--ink-900);
}

.page-about .ab-btn--solid:hover {
  background: var(--copper-300);
  transform: translateY(-2px);
}

.page-about .ab-btn--line {
  border-color: rgba(245, 240, 230, .42);
  color: var(--cream);
}

.page-about .ab-btn--line:hover {
  border-color: var(--copper-300);
  color: var(--copper-300);
}

/* ---------- 响应式 ---------- */
@media (min-width: 760px) {
  .page-about .ab-figure--wide img {
    aspect-ratio: 3 / 2;
  }

  .page-about .ab-figure--std img {
    aspect-ratio: 4 / 3;
  }

  .page-about .ab-figure--region img {
    aspect-ratio: 12 / 7;
  }
}

@media (min-width: 800px) {
  .page-about .ab-steps {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .ab-method-note {
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: end;
    gap: 2rem;
  }

  .page-about .ab-qitem {
    grid-template-columns: 46px 180px minmax(0, 1fr);
    align-items: baseline;
    gap: .4rem 1.2rem;
  }
}

@media (min-width: 820px) {
  .page-about .ab-team-cards {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .ab-cta-inner {
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: center;
    gap: 2.4rem;
  }
}

@media (min-width: 880px) {
  .page-about .ab-tl-item {
    display: grid;
    grid-template-columns: 168px minmax(0, 1fr);
    gap: 2rem;
    padding-left: 2rem;
  }

  .page-about .ab-tl-year {
    flex-direction: column;
    align-items: flex-start;
    gap: .3rem;
    margin-bottom: 0;
  }

  .page-about .ab-tl-y {
    font-size: 1.5rem;
  }
}

@media (min-width: 900px) {
  .page-about .ab-hero-grid {
    grid-template-columns: minmax(0, 1.55fr) minmax(0, 1fr);
    gap: 3.2rem;
    align-items: start;
  }

  .page-about .ab-team-top {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, .95fr);
    gap: 2.6rem;
    align-items: end;
  }

  .page-about .ab-team-top .ab-sec-head {
    margin-bottom: 0;
  }

  .page-about .ab-region-grid {
    grid-template-columns: minmax(0, .95fr) minmax(0, 1.05fr);
    gap: 3rem;
    align-items: center;
  }

  .page-about .ab-seal {
    display: grid;
    place-items: center;
    position: absolute;
    top: 0;
    right: 0;
    width: 96px;
    height: 96px;
    border: 2px solid rgba(176, 122, 42, .45);
    border-radius: 50%;
    background: rgba(217, 178, 124, .12);
    color: var(--copper-ink);
    font-family: var(--font-mono);
    font-size: .7rem;
    letter-spacing: .14em;
    line-height: 1.5;
    text-align: center;
    transform: rotate(-9deg);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .ab-team-card,
  .page-about .ab-btn,
  .page-about .ab-toc-list a,
  .page-about .ab-team-more {
    transition: none;
  }

  .page-about .ab-team-card:hover,
  .page-about .ab-team-card:focus-within,
  .page-about .ab-btn--solid:hover,
  .page-about .ab-toc-list a:hover {
    transform: none;
  }
}
<<<END>>>