.page-about {
  --ab-line: rgba(27, 51, 88, 0.16);
  --ab-line-dark: rgba(201, 209, 217, 0.18);
  background: var(--paper-100);
  color: var(--text-ink);
  font-family: var(--font-body);
  overflow-x: hidden;
}

/* ---------- 首屏 ---------- */
.page-about .ab-hero {
  position: relative;
  background: var(--ink-900);
  color: var(--paper-100);
  padding: clamp(22px, 4vw, 40px) 0 clamp(34px, 6vw, 76px);
  overflow: hidden;
}
.page-about .ab-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(var(--grid-line) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid-line) 1px, transparent 1px);
  background-size: 58px 58px;
  pointer-events: none;
}
.page-about .ab-hero::after {
  content: "";
  position: absolute;
  right: -10%;
  bottom: -40%;
  width: 60%;
  height: 120%;
  background: linear-gradient(150deg, transparent 40%, rgba(43, 224, 200, 0.1) 100%);
  transform: skewX(-6deg);
  pointer-events: none;
}
.page-about .ab-hero > .container {
  position: relative;
  z-index: 1;
}

.page-about .ab-hero .breadcrumb ol {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 0 0 clamp(18px, 4vw, 36px);
  padding: 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
}
.page-about .ab-hero .breadcrumb li {
  display: flex;
  align-items: center;
  gap: 8px;
  color: rgba(201, 209, 217, 0.62);
}
.page-about .ab-hero .breadcrumb li + li::before {
  content: "/";
  color: rgba(201, 209, 217, 0.3);
}
.page-about .ab-hero .breadcrumb a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(43, 224, 200, 0.35);
}
.page-about .ab-hero .breadcrumb a:hover {
  border-bottom-color: var(--cyan);
}

.page-about .ab-hero__title {
  margin: 12px 0 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(2.1rem, 5.2vw, 4.1rem);
  line-height: 1.08;
  letter-spacing: -0.02em;
  max-width: 20ch;
}
.page-about .ab-hero__lead {
  margin: clamp(18px, 3vw, 28px) 0 0;
  max-width: 62ch;
  font-size: clamp(1rem, 1.4vw, 1.15rem);
  line-height: 1.8;
  color: var(--metal-300);
}

.page-about .ab-hero__meta {
  margin-top: clamp(28px, 4vw, 46px);
  padding-top: 20px;
  border-top: 1px solid var(--ab-line-dark);
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px 20px;
}
.page-about .ab-meta {
  display: flex;
  flex-direction: column;
  gap: 6px;
  border-left: 2px solid var(--ink-700);
  padding-left: 12px;
}
.page-about .ab-meta__k {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  color: rgba(201, 209, 217, 0.6);
}
.page-about .ab-meta__v {
  font-family: var(--font-mono);
  font-size: clamp(1rem, 1.6vw, 1.25rem);
  color: var(--paper-100);
  letter-spacing: 0.02em;
}

/* ---------- 一段自述 ---------- */
.page-about .ab-story {
  position: relative;
  background: var(--ink-800);
  color: var(--paper-100);
  padding: clamp(44px, 8vw, 100px) 0;
  overflow: hidden;
}
.page-about .ab-story__bg {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: 0.18;
  filter: saturate(0.55) contrast(1.05);
}
.page-about .ab-story::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(105deg, var(--ink-800) 20%, rgba(16, 32, 60, 0.72) 70%, rgba(10, 20, 40, 0.9) 100%);
  pointer-events: none;
}
.page-about .ab-story__inner {
  position: relative;
  z-index: 1;
}
.page-about .ab-story__title {
  margin: 10px 0 clamp(20px, 3vw, 32px);
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(1.7rem, 3.4vw, 2.5rem);
  line-height: 1.2;
  letter-spacing: -0.01em;
  max-width: 24ch;
}
.page-about .ab-story__prose {
  max-width: 66ch;
}
.page-about .ab-story__prose p {
  color: var(--metal-300);
  line-height: 1.85;
  margin: 0 0 1.05em;
}
.page-about .ab-story__prose p:last-child {
  margin-bottom: 0;
}
.page-about .ab-dropcap::first-letter {
  float: left;
  font-family: var(--font-serif);
  font-size: 3.1em;
  line-height: 0.86;
  padding: 6px 12px 0 0;
  color: var(--cyan);
}
.page-about .ab-quote {
  margin: clamp(30px, 5vw, 52px) 0 0;
  padding: 18px 0 18px 22px;
  border-left: 1px solid var(--cyan);
  max-width: 46ch;
}
.page-about .ab-quote blockquote {
  margin: 0;
  font-family: var(--font-serif);
  font-size: clamp(1.1rem, 2vw, 1.45rem);
  line-height: 1.6;
  color: var(--paper-100);
}
.page-about .ab-quote figcaption {
  margin-top: 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: rgba(201, 209, 217, 0.66);
}

/* ---------- 通用章节 ---------- */
.page-about .ab-section {
  padding: clamp(44px, 7vw, 92px) 0;
}
.page-about .ab-section--paper {
  background: var(--paper-100);
  color: var(--text-ink);
}
.page-about .ab-section--flow {
  background: var(--paper-200);
  border-top: 1px solid rgba(27, 51, 88, 0.08);
}
.page-about .ab-section--dark {
  background: var(--ink-900);
  color: var(--paper-100);
}
.page-about .ab-section--promise {
  position: relative;
  background: var(--ink-800);
  color: var(--paper-100);
  overflow: hidden;
}
.page-about .ab-section--promise::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(var(--grid-line) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid-line) 1px, transparent 1px);
  background-size: 46px 46px;
  pointer-events: none;
}
.page-about .ab-section--promise > .container {
  position: relative;
  z-index: 1;
}

.page-about .ab-section__title {
  margin: 10px 0 clamp(14px, 2vw, 20px);
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(1.55rem, 3.2vw, 2.3rem);
  line-height: 1.22;
  letter-spacing: -0.01em;
  max-width: 26ch;
  color: var(--text-ink);
}
.page-about .ab-section__title--on-dark {
  color: var(--paper-100);
}
.page-about .ab-section__lead {
  margin: 0 0 clamp(24px, 4vw, 44px);
  max-width: 60ch;
  font-size: 1rem;
  line-height: 1.8;
  color: #3c4552;
}
.page-about .ab-section__lead--on-dark {
  color: var(--metal-300);
}

/* ---------- 时间线 ---------- */
.page-about .ab-timeline {
  display: grid;
  gap: 28px;
}
.page-about .ab-timeline__rail {
  border-top: 1px solid var(--ab-line);
  padding-top: 14px;
}
.page-about .ab-rail__caption {
  margin: 0 0 10px;
  font-size: 0.9rem;
  letter-spacing: 0.2em;
  color: var(--metal-600);
}
.page-about .ab-rail__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  gap: 8px;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  padding-bottom: 4px;
}
.page-about .ab-rail__link {
  display: inline-flex;
  align-items: baseline;
  gap: 6px;
  white-space: nowrap;
  padding: 7px 12px;
  border: 1px solid var(--ab-line);
  background: var(--paper-200);
  color: var(--text-ink);
  font-size: 13px;
  text-decoration: none;
  transition: border-color 200ms ease, background 200ms ease;
}
.page-about .ab-rail__link .mono {
  font-size: 12px;
  color: var(--cyan-text);
  letter-spacing: 0.06em;
}
.page-about .ab-rail__link:hover,
.page-about .ab-rail__link:focus-visible {
  border-color: var(--cyan-text);
  background: #fff;
}

.page-about .ab-timeline__entries {
  list-style: none;
  margin: 0;
  padding: 0 0 0 24px;
  border-left: 1px solid var(--ab-line);
}
.page-about .ab-entry {
  position: relative;
  padding: 0 0 clamp(28px, 4vw, 44px);
}
.page-about .ab-entry:last-child {
  padding-bottom: 0;
}
.page-about .ab-entry::before {
  content: "";
  position: absolute;
  left: -29px;
  top: 12px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--paper-100);
  border: 1px solid var(--ink-700);
  box-sizing: border-box;
}
.page-about .ab-entry:last-child::before {
  background: var(--orange);
  border-color: var(--orange);
}
.page-about .ab-entry__year {
  margin: 0;
  font-size: clamp(1.2rem, 2.2vw, 1.6rem);
  font-weight: 600;
  letter-spacing: 0.04em;
  color: var(--orange-text);
}
.page-about .ab-entry__title {
  margin: 4px 0 8px;
  font-family: var(--font-display);
  font-size: clamp(1.1rem, 1.9vw, 1.32rem);
  font-weight: 700;
  line-height: 1.4;
  color: var(--text-ink);
}
.page-about .ab-entry__text {
  margin: 0;
  max-width: 60ch;
  font-size: 0.98rem;
  line-height: 1.85;
  color: #3c4552;
}
.page-about .ab-entry__text a {
  color: var(--cyan-text);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.page-about .ab-figure {
  margin: 20px 0 0;
  border: 1px solid var(--ab-line);
  background: var(--paper-200);
  padding: 10px;
}
.page-about .ab-figure img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  object-fit: cover;
  aspect-ratio: 1 / 1;
}
.page-about .ab-figure__cap {
  margin: 10px 0 2px;
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--metal-600);
}

/* ---------- 流水线 ---------- */
.page-about .ab-flow__head {
  display: grid;
  gap: 24px;
  margin-bottom: clamp(26px, 4vw, 44px);
}
.page-about .ab-figure--flow {
  margin: 0;
  background: var(--paper-100);
  border: 1px solid rgba(27, 51, 88, 0.14);
  padding: 10px;
}
.page-about .ab-figure--flow img {
  aspect-ratio: 14 / 9;
}
.page-about .ab-flow__intro .ab-section__lead {
  margin-bottom: 0;
}

.page-about .ab-flow__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 12px;
}
.page-about .ab-flow__step {
  position: relative;
  background: var(--paper-100);
  border-left: 3px solid var(--orange);
  padding: 18px 18px 20px;
  transition: transform 200ms ease, box-shadow 200ms ease;
}
.page-about .ab-flow__step:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 20px rgba(10, 20, 40, 0.1);
}
.page-about .ab-flow__num {
  display: inline-block;
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--orange-text);
}
.page-about .ab-flow__name {
  margin: 6px 0 4px;
  font-family: var(--font-display);
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text-ink);
}
.page-about .ab-flow__role {
  margin: 0 0 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--cyan-text);
}
.page-about .ab-flow__out {
  margin: 0;
  font-size: 0.92rem;
  line-height: 1.75;
  color: #3c4552;
}
.page-about .ab-flow__out a {
  color: var(--cyan-text);
  text-decoration: underline;
  text-underline-offset: 3px;
}

/* ---------- 团队 ---------- */
.page-about .ab-team {
  display: grid;
  gap: 14px;
}
.page-about .ab-card {
  position: relative;
  background: var(--ink-800);
  border: 1px solid var(--ab-line-dark);
  padding: 22px 20px 24px;
  clip-path: polygon(0 0, calc(100% - 16px) 0, 100% 16px, 100% 100%, 0 100%);
  transition: border-color 200ms ease;
}
.page-about .ab-card:hover {
  border-color: var(--cyan);
}
.page-about .ab-card__num {
  margin: 0;
  font-size: 2.1rem;
  line-height: 1;
  letter-spacing: 0.02em;
  color: var(--cyan);
}
.page-about .ab-card__role {
  margin: 10px 0 8px;
  font-family: var(--font-display);
  font-size: 1.06rem;
  font-weight: 700;
  color: var(--paper-100);
}
.page-about .ab-card__desc {
  margin: 0;
  font-size: 0.92rem;
  line-height: 1.8;
  color: var(--metal-300);
}

/* ---------- 客户 ---------- */
.page-about .ab-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--ab-line);
  border: 1px solid var(--ab-line);
  margin-bottom: clamp(26px, 4vw, 44px);
}
.page-about .ab-stat {
  background: var(--paper-100);
  padding: 18px 16px 20px;
}
.page-about .ab-stat__num {
  margin: 0;
  font-size: clamp(1.5rem, 3vw, 2rem);
  line-height: 1.1;
  letter-spacing: 0.01em;
  color: var(--text-ink);
}
.page-about .ab-stat__num span {
  font-size: 0.72em;
  margin-left: 2px;
  color: var(--metal-600);
}
.page-about .ab-stat__label {
  margin: 8px 0 0;
  font-size: 0.86rem;
  line-height: 1.6;
  color: var(--metal-600);
}
.page-about .ab-clients__body {
  gap: clamp(20px, 3vw, 40px);
}
.page-about .ab-clients__body .prose p {
  margin: 0 0 1em;
  line-height: 1.85;
  color: #3c4552;
}
.page-about .ab-clients__body .prose p:last-child {
  margin-bottom: 0;
}

/* ---------- 承诺 ---------- */
.page-about .ab-promises {
  display: grid;
  gap: 16px;
}
.page-about .ab-promise {
  border-top: 1px solid var(--cyan);
  padding-top: 16px;
}
.page-about .ab-promise__num {
  margin: 0;
  font-size: 1.5rem;
  letter-spacing: 0.08em;
  color: rgba(43, 224, 200, 0.85);
}
.page-about .ab-promise__title {
  margin: 8px 0 10px;
  font-family: var(--font-display);
  font-size: 1.12rem;
  font-weight: 700;
  color: var(--paper-100);
}
.page-about .ab-promise__text {
  margin: 0;
  font-size: 0.94rem;
  line-height: 1.85;
  color: var(--metal-300);
}
.page-about .ab-cta {
  margin-top: clamp(30px, 4vw, 46px);
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

/* ---------- 响应式 ---------- */
@media (min-width: 640px) {
  .page-about .ab-hero__meta {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
  .page-about .ab-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
  .page-about .ab-team {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  .page-about .ab-flow__list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  .page-about .ab-figure {
    max-width: 460px;
  }
}

@media (min-width: 900px) {
  .page-about .ab-timeline {
    grid-template-columns: 200px minmax(0, 1fr);
    gap: clamp(28px, 4vw, 64px);
    align-items: start;
  }
  .page-about .ab-timeline__rail {
    position: sticky;
    top: 28px;
    border-top: none;
    border-left: 1px solid var(--ab-line);
    padding: 0 0 0 16px;
  }
  .page-about .ab-rail__list {
    flex-direction: column;
    overflow: visible;
  }
  .page-about .ab-rail__link {
    width: 100%;
    justify-content: flex-start;
    background: transparent;
    border-color: transparent;
    border-bottom: 1px solid var(--ab-line);
    padding: 9px 0;
  }
  .page-about .ab-rail__link:hover,
  .page-about .ab-rail__link:focus-visible {
    background: var(--paper-200);
    border-color: transparent;
    border-bottom-color: var(--cyan);
  }
  .page-about .ab-flow__head {
    grid-template-columns: minmax(0, 5fr) minmax(0, 6fr);
    gap: clamp(24px, 4vw, 52px);
    align-items: end;
  }
  .page-about .ab-figure--flow {
    margin: 0;
  }
  .page-about .ab-entry--wide .ab-figure {
    max-width: 520px;
  }
  .page-about .ab-team {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
  .page-about .ab-promises {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 24px;
  }
}

@media (min-width: 1080px) {
  .page-about .ab-flow__list {
    grid-template-columns: repeat(5, minmax(0, 1fr));
    gap: 8px;
  }
  .page-about .ab-flow__step {
    border-left: none;
    padding: 20px 20px 22px 24px;
    clip-path: polygon(0 0, calc(100% - 16px) 0, 100% 50%, calc(100% - 16px) 100%, 0 100%);
  }
  .page-about .ab-flow__step:first-child {
    clip-path: polygon(0 0, calc(100% - 16px) 0, 100% 50%, calc(100% - 16px) 100%, 0 100%);
  }
  .page-about .ab-flow__step::after {
    content: "";
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    width: 3px;
    background: var(--orange);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .ab-flow__step,
  .page-about .ab-card,
  .page-about .ab-rail__link {
    transition: none;
  }
  .page-about .ab-flow__step:hover {
    transform: none;
  }
}
<<<END>>>