.page-about {
  --ab-prose-max: 42em;
  --ab-rail-w: 104px;
  --ab-gold-line: rgba(201, 169, 110, 0.32);
  --ab-ink-soft: #242424;
}

/* ---------- 首屏 ---------- */

.page-about .ab-hero {
  position: relative;
  overflow: hidden;
  padding: clamp(20px, 3vw, 34px) var(--gutter) clamp(38px, 6vw, 76px);
  background-color: var(--c-porcelain);
  background-image:
    linear-gradient(to right, var(--c-grid) 1px, transparent 1px),
    linear-gradient(to bottom, var(--c-grid) 1px, transparent 1px);
  background-size: 96px 96px;
  background-position: center top;
}

.page-about .ab-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, rgba(247, 244, 239, 0.55), var(--c-porcelain) 72%);
  pointer-events: none;
}

.page-about .ab-crumb {
  position: relative;
  z-index: 1;
  margin-bottom: clamp(18px, 2.6vw, 30px);
}

.page-about .ab-hero-grid {
  position: relative;
  z-index: 1;
  max-width: var(--wrap-max);
  margin-inline: auto;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(26px, 4vw, 52px);
  align-items: center;
}

.page-about .ab-kicker {
  margin: 0 0 14px;
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--c-gold);
}

.page-about .ab-h1 {
  margin: 0;
  font-family: var(--font-serif);
  font-weight: 800;
  font-size: clamp(30px, 4.4vw, 52px);
  line-height: 1.24;
  letter-spacing: 0.02em;
  color: var(--c-ink);
}

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

.page-about .ab-lede {
  margin: 20px 0 0;
  max-width: 36em;
  font-size: clamp(15px, 1.5vw, 17px);
  line-height: 1.85;
  color: var(--c-graphite);
}

.page-about .ab-hero-tags {
  list-style: none;
  margin: 24px 0 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.page-about .ab-hero-figure {
  margin: 0;
  background: var(--c-white);
  border: 1px solid var(--c-line);
  box-shadow: var(--shadow-paper);
  overflow: hidden;
}

.page-about .ab-hero-figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 1400 / 800;
  object-fit: cover;
}

.page-about .ab-hero-figure .frame-caption {
  padding: 12px 16px;
  margin: 0;
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--c-graphite);
  border-top: 1px solid var(--c-line-soft);
}

/* ---------- 主体骨架 ---------- */

.page-about .ab-body {
  max-width: var(--wrap-max);
  margin-inline: auto;
  padding-inline: var(--gutter);
  display: grid;
  grid-template-columns: minmax(0, 1fr);
}

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

.page-about .ab-rail-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 54px;
}

.page-about .ab-rail-link {
  position: relative;
  display: block;
  padding-left: 28px;
  text-decoration: none;
  color: var(--c-graphite);
}

.page-about .ab-rail-link::before {
  content: "";
  position: absolute;
  left: 4px;
  top: 4px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--c-gold);
  box-shadow: 0 0 0 4px rgba(201, 169, 110, 0.16);
  transition: background-color 0.3s var(--ease), box-shadow 0.3s var(--ease);
}

.page-about .ab-rail-link::after {
  content: "";
  position: absolute;
  left: 8px;
  top: 20px;
  height: calc(100% + 40px);
  width: 1px;
  background: linear-gradient(180deg, var(--c-gold), rgba(201, 169, 110, 0.08));
}

.page-about .ab-rail-item:last-child .ab-rail-link::after {
  display: none;
}

.page-about .ab-rail-link:hover::before {
  background: var(--c-red);
  box-shadow: 0 0 0 4px rgba(200, 16, 46, 0.16);
}

.page-about .ab-rail-no {
  display: block;
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--c-gold);
}

.page-about .ab-rail-label {
  display: block;
  margin-top: 3px;
  font-size: 13px;
  letter-spacing: 0.06em;
}

.page-about .ab-flow {
  min-width: 0;
  padding-bottom: clamp(40px, 5vw, 78px);
}

/* ---------- 章节 ---------- */

.page-about .ab-sec {
  padding-block: clamp(40px, 5vw, 68px);
  border-top: 1px solid var(--c-line-soft);
  scroll-margin-top: 140px;
}

.page-about .ab-sec:first-child {
  border-top: 0;
  padding-top: clamp(26px, 3.5vw, 46px);
}

.page-about .ab-sec-head {
  position: relative;
  padding-left: 18px;
}

.page-about .ab-sec-head::before {
  content: "";
  position: absolute;
  left: 0;
  top: 6px;
  width: 3px;
  height: 30px;
  background: var(--c-red);
}

.page-about .ab-sec-no {
  margin: 0 0 10px;
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--c-gold);
}

.page-about .ab-sec-title {
  margin: 0;
  font-family: var(--font-serif);
  font-weight: 800;
  font-size: clamp(23px, 2.6vw, 32px);
  line-height: 1.34;
  letter-spacing: 0.015em;
  color: var(--c-ink);
}

.page-about .ab-sec-sub {
  margin: 14px 0 0;
  max-width: 38em;
  font-size: 15px;
  line-height: 1.85;
  color: var(--c-graphite);
}

.page-about .ab-prose {
  margin-top: clamp(20px, 2.6vw, 28px);
  max-width: var(--ab-prose-max);
}

.page-about .ab-prose p {
  margin: 0 0 16px;
  font-size: 16px;
  line-height: 1.9;
  color: var(--c-text);
}

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

.page-about .ab-prose-after {
  margin-top: clamp(22px, 3vw, 32px);
}

.page-about .ab-sec .callout {
  margin-top: clamp(22px, 3vw, 30px);
  max-width: var(--ab-prose-max);
}

.page-about .ab-sec .callout p {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
}

.page-about .ab-sec .callout .callout-title {
  margin-bottom: 6px;
  font-weight: 700;
}

/* ---------- 团队角色 ---------- */

.page-about .ab-roles {
  margin-top: clamp(24px, 3vw, 34px);
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 16px;
}

.page-about .ab-role {
  background: var(--c-white);
  border: 1px solid var(--c-line);
  box-shadow: var(--shadow-paper);
  padding: clamp(20px, 2.4vw, 28px);
  transition: border-color 0.35s var(--ease), box-shadow 0.35s var(--ease), transform 0.35s var(--ease);
}

.page-about .ab-role:hover {
  border-color: var(--c-gold);
  box-shadow: var(--shadow-lift);
  transform: translateY(-3px);
}

.page-about .ab-role-idx {
  margin: 0;
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--c-gold);
}

.page-about .ab-role-title {
  margin: 10px 0 0;
  font-family: var(--font-serif);
  font-size: 20px;
  font-weight: 700;
  letter-spacing: 0.02em;
  color: var(--c-ink);
}

.page-about .ab-role-text {
  margin: 12px 0 0;
  font-size: 15px;
  line-height: 1.82;
  color: var(--c-graphite);
}

.page-about .ab-flow-figure {
  margin: clamp(26px, 3.4vw, 38px) 0 0;
  padding: clamp(18px, 2.4vw, 28px);
  background: var(--c-porcelain);
  border: 1px solid var(--c-line-soft);
}

.page-about .ab-flow-svg {
  display: block;
  width: 100%;
  max-width: 460px;
  height: auto;
  margin-inline: auto;
}

.page-about .ab-flow-figure .frame-caption {
  margin: 14px 0 0;
  text-align: center;
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--c-graphite);
}

/* ---------- 数据带 ---------- */

.page-about .ab-stats {
  position: relative;
  margin-top: clamp(24px, 3vw, 34px);
  padding: clamp(24px, 3vw, 36px) clamp(16px, 2.4vw, 30px);
  background: var(--c-ink);
  border-top: 3px solid var(--c-red);
  overflow: hidden;
}

.page-about .ab-stats::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--c-red), var(--c-gold));
}

.page-about .ab-stat-row {
  list-style: none;
  margin: 0;
  padding: 0 0 6px;
  display: grid;
  grid-auto-flow: column;
  grid-auto-columns: 74%;
  gap: 0;
  overflow-x: auto;
  scroll-snap-type: x proximity;
  scrollbar-width: thin;
}

.page-about .ab-stat {
  scroll-snap-align: start;
  padding: 4px clamp(14px, 2vw, 26px);
  border-left: 1px solid var(--ab-gold-line);
}

.page-about .ab-stat:first-child {
  border-left: 0;
  padding-left: 0;
}

.page-about .ab-stat-val {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(28px, 3.6vw, 42px);
  line-height: 1;
  letter-spacing: -0.01em;
  color: var(--c-gold);
  transition: transform 0.35s var(--ease);
}

.page-about .ab-stat-val small {
  font-size: 0.45em;
  margin-left: 3px;
  letter-spacing: 0;
  color: var(--c-gold-light);
}

.page-about .ab-stat-label {
  display: block;
  margin-top: 12px;
  font-size: 13px;
  line-height: 1.65;
  color: rgba(247, 244, 239, 0.68);
}

.page-about .ab-stats:hover .ab-stat-val {
  transform: translateY(-2px);
}

/* ---------- 节奏表 ---------- */

.page-about .ab-cadence {
  list-style: none;
  margin: clamp(22px, 3vw, 32px) 0 0;
  padding: 0;
  border-top: 1px solid var(--c-line);
  max-width: 56em;
}

.page-about .ab-cadence-item {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 6px;
  padding: 18px 0;
  border-bottom: 1px solid var(--c-line);
  transition: background-color 0.3s var(--ease);
}

.page-about .ab-cadence-item:hover {
  background: rgba(201, 169, 110, 0.08);
}

.page-about .ab-cadence-num {
  font-size: 17px;
  letter-spacing: 0.02em;
  color: var(--c-red);
}

.page-about .ab-cadence-text {
  font-size: 15px;
  line-height: 1.78;
  color: var(--c-graphite);
}

/* ---------- 生态 ---------- */

.page-about .ab-eco {
  margin-top: clamp(24px, 3vw, 34px);
  display: grid;
  gap: 0;
  max-width: 62em;
}

.page-about .ab-eco-item {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 8px;
  padding: clamp(18px, 2.4vw, 26px) 0;
  border-bottom: 1px solid var(--c-line-soft);
}

.page-about .ab-eco-item:first-child {
  border-top: 1px solid var(--c-line-soft);
}

.page-about .ab-eco-key {
  font-size: 22px;
  line-height: 1.1;
  letter-spacing: 0.02em;
  color: var(--c-jade);
}

.page-about .ab-eco-title {
  margin: 0;
  font-family: var(--font-serif);
  font-size: 18px;
  font-weight: 700;
  letter-spacing: 0.02em;
  color: var(--c-ink);
}

.page-about .ab-eco-body p {
  margin: 10px 0 0;
  font-size: 15px;
  line-height: 1.82;
  color: var(--c-graphite);
}

.page-about .ab-eco-more {
  margin: clamp(20px, 2.6vw, 28px) 0 0;
  font-size: 15px;
  line-height: 1.85;
  color: var(--c-graphite);
}

.page-about .ab-eco-more a {
  color: var(--c-red);
  text-decoration: none;
  border-bottom: 1px solid var(--c-gold);
  padding-bottom: 1px;
  transition: color 0.3s var(--ease), border-color 0.3s var(--ease);
}

.page-about .ab-eco-more a:hover {
  color: var(--c-red-deep);
  border-color: var(--c-red);
}

/* ---------- 时间线 ---------- */

.page-about .ab-tl-figure {
  margin: clamp(24px, 3vw, 34px) 0 0;
  border: 1px solid var(--c-line-soft);
  background: var(--c-white);
  overflow: hidden;
}

.page-about .ab-tl-figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 1200 / 480;
  object-fit: cover;
}

.page-about .ab-tl-figure .frame-caption {
  padding: 10px 16px;
  margin: 0;
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--c-graphite);
  border-top: 1px solid var(--c-line-soft);
}

.page-about .ab-timeline {
  list-style: none;
  margin: clamp(26px, 3.4vw, 38px) 0 0;
  padding: 0;
}

.page-about .ab-tl-item {
  position: relative;
  padding: 0 0 clamp(24px, 3vw, 34px) 30px;
}

.page-about .ab-tl-item::before {
  content: "";
  position: absolute;
  left: 3px;
  top: 6px;
  width: 11px;
  height: 11px;
  border-radius: 50%;
  background: var(--c-porcelain);
  border: 2px solid var(--c-gold);
  transition: background-color 0.3s var(--ease), border-color 0.3s var(--ease);
}

.page-about .ab-tl-item::after {
  content: "";
  position: absolute;
  left: 9px;
  top: 22px;
  bottom: 0;
  width: 1px;
  background: var(--c-line);
}

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

.page-about .ab-tl-item:last-child::after {
  display: none;
}

.page-about .ab-tl-item:hover::before {
  background: var(--c-red);
  border-color: var(--c-red);
}

.page-about .ab-tl-phase {
  margin: 0;
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--c-gold);
}

.page-about .ab-tl-title {
  margin: 7px 0 0;
  font-family: var(--font-serif);
  font-size: 17px;
  font-weight: 700;
  line-height: 1.55;
  letter-spacing: 0.01em;
  color: var(--c-ink);
}

.page-about .ab-tl-text {
  margin: 8px 0 0;
  max-width: 40em;
  font-size: 15px;
  line-height: 1.82;
  color: var(--c-graphite);
}

/* ---------- 结尾指引 ---------- */

.page-about .ab-next {
  background: var(--c-ink);
  padding: clamp(38px, 5vw, 70px) var(--gutter);
}

.page-about .ab-next-inner {
  max-width: var(--wrap-max);
  margin-inline: auto;
}

.page-about .ab-next-kicker {
  margin: 0;
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--c-gold);
}

.page-about .ab-next-title {
  margin: 12px 0 0;
  font-family: var(--font-serif);
  font-weight: 800;
  font-size: clamp(22px, 2.4vw, 30px);
  letter-spacing: 0.02em;
  color: var(--c-porcelain);
}

.page-about .ab-next-grid {
  margin-top: clamp(22px, 3vw, 32px);
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  background: var(--ab-gold-line);
}

.page-about .ab-next-card {
  display: block;
  padding: clamp(20px, 2.6vw, 28px);
  background: var(--c-ink);
  text-decoration: none;
  color: inherit;
  transition: background-color 0.3s var(--ease), box-shadow 0.3s var(--ease);
}

.page-about .ab-next-card:hover,
.page-about .ab-next-card:focus-visible {
  background: var(--ab-ink-soft);
  box-shadow: inset 3px 0 0 var(--c-red);
}

.page-about .ab-next-no {
  display: block;
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--c-gold);
}

.page-about .ab-next-name {
  display: block;
  margin-top: 10px;
  font-family: var(--font-serif);
  font-size: 19px;
  font-weight: 700;
  letter-spacing: 0.03em;
  color: var(--c-porcelain);
}

.page-about .ab-next-desc {
  display: block;
  margin-top: 10px;
  font-size: 14px;
  line-height: 1.75;
  color: rgba(247, 244, 239, 0.66);
}

/* ---------- 响应式 ---------- */

@media (min-width: 700px) {
  .page-about .ab-cadence-item {
    grid-template-columns: 158px minmax(0, 1fr);
    align-items: baseline;
    gap: 22px;
    padding: 20px 0;
  }

  .page-about .ab-eco-item {
    grid-template-columns: 132px minmax(0, 1fr);
    align-items: start;
    gap: 26px;
  }
}

@media (min-width: 760px) {
  .page-about .ab-roles {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

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

@media (min-width: 880px) {
  .page-about .ab-stat-row {
    grid-auto-flow: row;
    grid-template-columns: repeat(4, minmax(0, 1fr));
    overflow: visible;
  }
}

@media (min-width: 940px) {
  .page-about .ab-hero-grid {
    grid-template-columns: minmax(0, 6fr) minmax(0, 6fr);
    gap: clamp(32px, 4vw, 60px);
  }

  .page-about .ab-br {
    display: inline;
  }
}

@media (min-width: 1024px) {
  .page-about .ab-body {
    grid-template-columns: var(--ab-rail-w) minmax(0, 1fr);
    column-gap: clamp(28px, 3.4vw, 56px);
  }

  .page-about .ab-rail {
    display: block;
  }

  .page-about .ab-rail-inner {
    position: sticky;
    top: 132px;
    padding-top: 32px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .ab-role,
  .page-about .ab-stat-val,
  .page-about .ab-rail-link::before,
  .page-about .ab-tl-item::before,
  .page-about .ab-next-card {
    transition: none;
  }

  .page-about .ab-role:hover,
  .page-about .ab-stats:hover .ab-stat-val {
    transform: none;
  }
}