.page-about {
  --about-deep-rgb: 10, 25, 47;
  --about-gold-rgb: 212, 175, 55;
  background-color: var(--cream);
  overflow-x: hidden;
}

/* ===== 首屏 Hero：深蓝底 + 对角动势 ===== */
.page-about .about-hero {
  position: relative;
  padding: 120px 20px 64px;
  background: linear-gradient(150deg, var(--deep-blue) 0%, var(--deep-blue) 58%, #0d2040 58%, #122a4d 100%);
  color: var(--cream);
  overflow: hidden;
  border-radius: 0 0 var(--radius-lg) var(--radius-lg);
}
.page-about .about-hero::after {
  content: "";
  position: absolute;
  right: -70px;
  bottom: -70px;
  width: 220px;
  height: 220px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(var(--about-gold-rgb), 0.28), transparent 68%);
  pointer-events: none;
}
.page-about .about-hero__bg {
  position: absolute;
  inset: 0;
  opacity: 0.4;
  pointer-events: none;
}
.page-about .about-hero__bg img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}
.page-about .about-hero__inner {
  position: relative;
  z-index: 1;
  max-width: var(--content-width);
  margin: 0 auto;
}
.page-about .about-hero__inner > * {
  animation: about-rise 0.55s ease both;
}
.page-about .about-hero__inner > *:nth-child(2) { animation-delay: 0.08s; }
.page-about .about-hero__inner > *:nth-child(3) { animation-delay: 0.16s; }
.page-about .about-hero__inner > *:nth-child(4) { animation-delay: 0.24s; }

@keyframes about-rise {
  from { opacity: 0; transform: translateY(18px); }
  to { opacity: 1; transform: translateY(0); }
}

.page-about .about-hero .breadcrumb {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 28px;
  font-size: 13px;
}
.page-about .about-hero .breadcrumb a {
  color: rgba(245, 240, 230, 0.7);
  text-decoration: none;
  transition: color 0.2s ease;
}
.page-about .about-hero .breadcrumb a:hover {
  color: var(--gold);
}
.page-about .about-hero .breadcrumb .breadcrumb__sep {
  color: rgba(245, 240, 230, 0.4);
}
.page-about .about-hero .breadcrumb [aria-current="page"] {
  color: var(--gold);
}

.page-about .about-hero h1 {
  font-family: var(--font-head);
  font-size: clamp(28px, 5vw, 44px);
  font-weight: 900;
  line-height: 1.16;
  letter-spacing: -0.02em;
  max-width: 760px;
  margin: 0 0 18px;
}
.page-about .about-hero__lead {
  font-size: 17px;
  line-height: 1.75;
  color: var(--text-dark-muted);
  max-width: 560px;
  margin: 0 0 36px;
}

.page-about .about-hero__stats {
  display: inline-flex;
  flex-wrap: wrap;
  gap: 14px 40px;
  padding: 20px 24px;
  background: rgba(245, 240, 230, 0.08);
  -webkit-backdrop-filter: blur(12px);
  backdrop-filter: blur(12px);
  border: 1px solid rgba(245, 240, 230, 0.18);
  border-radius: var(--radius-md);
}
.page-about .about-hero__stats .hero-metric__value {
  display: block;
  font-family: var(--font-mono);
  font-size: 30px;
  font-weight: 700;
  line-height: 1.2;
  color: var(--gold);
}
.page-about .about-hero__stats .hero-metric__label {
  display: block;
  font-size: 12px;
  letter-spacing: 0.08em;
  color: rgba(245, 240, 230, 0.7);
  margin-top: 4px;
}

/* ===== 左右分屏：左侧目录 + 右侧长叙事 ===== */
.page-about .about-split {
  display: block;
  max-width: var(--content-width);
  margin: 0 auto;
  padding: 0 20px;
}

/* 移动端索引条：顶部横向胶囊滚动 */
.page-about .index-rail {
  position: sticky;
  top: 76px;
  z-index: 6;
  margin: -28px 0 36px;
  padding: 12px 14px;
  background: rgba(var(--about-deep-rgb), 0.92);
  -webkit-backdrop-filter: blur(12px);
  backdrop-filter: blur(12px);
  border: 1px solid rgba(245, 240, 230, 0.16);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-soft);
  overflow-x: auto;
  scrollbar-width: none;
}
.page-about .index-rail::-webkit-scrollbar { display: none; }
.page-about .index-rail__label {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--gold);
  margin: 0 0 10px;
}
.page-about .index-rail__list {
  display: flex;
  gap: 8px;
  padding: 0;
  margin: 0;
  list-style: none;
  white-space: nowrap;
}
.page-about .index-rail__link {
  display: inline-block;
  color: var(--text-dark-muted);
  font-size: 13px;
  padding: 6px 14px;
  border-radius: var(--radius-pill);
  border: 1px solid rgba(245, 240, 230, 0.22);
  text-decoration: none;
  transition: color 0.2s ease, border-color 0.2s ease, background 0.2s ease;
}
.page-about .index-rail__link:hover,
.page-about .index-rail__link.is-active {
  color: var(--gold);
  border-color: var(--gold);
  background: rgba(var(--about-gold-rgb), 0.1);
}
.page-about .index-rail__note {
  display: none;
}

/* ===== 右则叙事正文 ===== */
.page-about .about-story {
  padding: 8px 0 64px;
}
.page-about .about-section {
  margin-bottom: 72px;
  scroll-margin-top: 120px;
}
.page-about .section__kicker {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--gold);
  font-weight: 600;
}
.page-about .section__title {
  font-family: var(--font-head);
  font-size: clamp(24px, 3vw, 32px);
  font-weight: 900;
  line-height: 1.25;
  letter-spacing: -0.01em;
  color: var(--ink);
  margin: 8px 0 0;
}
.page-about .about-body,
.page-about .about-intro {
  max-width: 720px;
  font-size: 16px;
  line-height: 1.9;
  color: #333b45;
  margin: 0 0 18px;
}
.page-about .about-intro {
  font-family: var(--font-mono);
  font-size: 14px;
  color: var(--stone);
  letter-spacing: 0.02em;
}

/* 引用卡 */
.page-about .about-quote {
  max-width: 700px;
  margin: 40px auto;
  padding: 26px 30px;
  background: rgba(var(--about-gold-rgb), 0.08);
  border-left: 4px solid var(--gold);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  font-size: 18px;
  font-weight: 600;
  line-height: 1.7;
  color: var(--ink);
}
.page-about .about-quote p { margin: 0; }
.page-about .about-quote--gold {
  background: linear-gradient(135deg, rgba(var(--about-gold-rgb), 0.16), rgba(var(--about-gold-rgb), 0.04));
  border-left-color: var(--gold);
}

/* ===== 时间线 ===== */
.page-about .about-timeline {
  position: relative;
  margin: 40px 0 48px;
  padding: 0;
  max-width: 760px;
}
.page-about .about-timeline::before {
  content: "";
  position: absolute;
  left: 7px;
  top: 6px;
  bottom: 6px;
  width: 3px;
  background: linear-gradient(to bottom, var(--gold) 0%, var(--deep-blue) 100%);
  border-radius: var(--radius-pill);
}
.page-about .about-timeline .timeline__item {
  position: relative;
  padding: 0 0 38px 36px;
  margin: 0;
}
.page-about .about-timeline .timeline__item::before {
  content: "";
  position: absolute;
  left: 0;
  top: 4px;
  width: 15px;
  height: 15px;
  border-radius: 50%;
  background: var(--gold);
  box-shadow: 0 0 0 5px var(--cream), 0 0 0 7px rgba(var(--about-gold-rgb), 0.4);
}
.page-about .timeline__time {
  display: block;
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.08em;
  color: var(--gold);
  margin-bottom: 6px;
}
.page-about .timeline__title {
  font-size: 19px;
  font-weight: 800;
  color: var(--ink);
  margin: 0 0 8px;
}
.page-about .timeline__text {
  font-size: 15px;
  line-height: 1.78;
  color: #444b55;
  max-width: 640px;
}

/* ===== 图表 ===== */
.page-about .about-figure {
  margin: 44px 0;
}
.page-about .about-figure img {
  display: block;
  width: 100%;
  height: auto;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-soft);
  object-fit: cover;
}
.page-about .figure__caption {
  display: block;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--stone);
  margin-top: 12px;
  text-align: center;
}

/* ===== 深色双引擎区块 ===== */
.page-about .about-section--dark {
  background: linear-gradient(135deg, var(--deep-blue) 0%, #0f2445 100%);
  color: var(--text-dark);
  border-radius: var(--radius-lg);
  padding: 40px 20px;
  box-shadow: var(--shadow-soft);
}
.page-about .about-section--dark .section__title {
  color: var(--cream);
}
.page-about .about-section--dark .about-body {
  color: var(--text-dark-muted);
}
.page-about .about-dual {
  display: grid;
  gap: 20px;
  margin-top: 32px;
}
.page-about .about-dual__item {
  background: rgba(245, 240, 230, 0.07);
  border: 1px solid rgba(245, 240, 230, 0.14);
  border-radius: var(--radius-md);
  padding: 26px 22px;
}
.page-about .about-dual__num {
  font-family: var(--font-mono);
  font-size: 26px;
  font-weight: 700;
  color: var(--gold);
  opacity: 0.85;
  margin-bottom: 8px;
}
.page-about .about-dual__item h3 {
  font-size: 19px;
  font-weight: 800;
  color: var(--cream);
  margin: 0 0 12px;
}
.page-about .about-dual__item p {
  font-size: 14px;
  line-height: 1.78;
  color: var(--text-dark-muted);
  margin: 0;
}
.page-about .about-dual__list {
  margin: 16px 0 0;
  padding: 0;
  list-style: none;
}
.page-about .about-dual__list li {
  position: relative;
  padding-left: 18px;
  margin-bottom: 8px;
  font-size: 13px;
  line-height: 1.6;
  color: var(--text-dark-muted);
}
.page-about .about-dual__list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 7px;
  width: 8px;
  height: 8px;
  border-radius: 2px;
  background: var(--orange);
}
.page-about .about-coop {
  margin-top: 26px;
  padding: 18px 20px;
  background: rgba(var(--about-gold-rgb), 0.1);
  border-radius: var(--radius-md);
  font-size: 14px;
  line-height: 1.8;
  color: var(--text-dark-muted);
}
.page-about .about-coop p { margin: 0; }

/* ===== 生态网格 ===== */
.page-about .about-ecosystem {
  display: grid;
  gap: 18px;
  margin-top: 32px;
}
.page-about .about-ecosystem__card {
  background: var(--white);
  border-radius: var(--radius-md);
  padding: 26px 22px;
  border-top: 3px solid var(--gold);
  box-shadow: var(--shadow-soft);
  transition: transform 0.25s ease, box-shadow 0.25s ease;
}
.page-about .about-ecosystem__card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lift);
}
.page-about .about-ecosystem__card h3 {
  font-size: 18px;
  font-weight: 800;
  color: var(--ink);
  margin: 0 0 10px;
}
.page-about .about-ecosystem__card p {
  font-size: 14px;
  line-height: 1.78;
  color: #555d68;
  margin: 0;
}

/* ===== 底部 CTA ===== */
.page-about .about-cta {
  margin-top: 24px;
  padding: 44px 24px;
  background: linear-gradient(145deg, var(--deep-blue) 0%, #10264a 100%);
  border-radius: var(--radius-lg);
  color: var(--cream);
  text-align: center;
  position: relative;
  overflow: hidden;
  box-shadow: var(--shadow-soft);
}
.page-about .about-cta::before {
  content: "";
  position: absolute;
  right: -70px;
  top: -70px;
  width: 220px;
  height: 220px;
  background: radial-gradient(circle, rgba(var(--about-gold-rgb), 0.22), transparent 70%);
  pointer-events: none;
}
.page-about .about-cta__inner { position: relative; z-index: 1; }
.page-about .about-cta h2 {
  font-size: clamp(22px, 3vw, 30px);
  font-weight: 900;
  margin: 10px 0 12px;
  line-height: 1.3;
}
.page-about .about-cta__inner p {
  color: var(--text-dark-muted);
  max-width: 520px;
  margin: 0 auto 26px;
  line-height: 1.75;
}
.page-about .about-cta__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  justify-content: center;
}
.page-about .about-cta__actions .btn--ghost {
  border-color: rgba(245, 240, 230, 0.35);
  color: var(--cream);
}
.page-about .about-cta__actions .btn--ghost:hover {
  border-color: var(--gold);
  color: var(--gold);
}

/* ===== 桌面端布局重置 ===== */
@media (min-width: 768px) {
  .page-about .about-section--dark {
    padding: 52px 44px;
  }
  .page-about .about-ecosystem {
    grid-template-columns: repeat(2, 1fr);
    gap: 22px;
  }
  .page-about .about-dual {
    grid-template-columns: repeat(2, 1fr);
    gap: 24px;
  }
  .page-about .about-dual__item {
    padding: 30px 28px;
  }
  .page-about .about-cta {
    padding: 56px 40px;
  }
}

@media (min-width: 1024px) {
  .page-about .about-split {
    display: grid;
    grid-template-columns: 220px minmax(0, 1fr);
    gap: 56px;
    padding: 0 32px;
  }
  .page-about .index-rail {
    position: sticky;
    top: 104px;
    height: fit-content;
    margin: 56px 0 0;
    padding: 8px 0;
    background: transparent;
    border: none;
    box-shadow: none;
    -webkit-backdrop-filter: none;
    backdrop-filter: none;
    overflow: visible;
  }
  .page-about .index-rail__list {
    flex-direction: column;
    align-items: flex-start;
    gap: 0;
    padding-left: 18px;
    border-left: 1px solid rgba(138, 140, 137, 0.35);
    white-space: normal;
  }
  .page-about .index-rail__link {
    display: block;
    border: none;
    border-radius: 0;
    background: none;
    color: var(--ink);
    font-size: 14px;
    padding: 9px 0;
    position: relative;
    transition: color 0.2s ease;
  }
  .page-about .index-rail__link::before {
    content: "";
    position: absolute;
    left: -19px;
    top: 50%;
    transform: translateY(-50%);
    width: 3px;
    height: 0;
    background: var(--gold);
    border-radius: var(--radius-pill);
    transition: height 0.25s ease;
  }
  .page-about .index-rail__link:hover,
  .page-about .index-rail__link.is-active {
    color: var(--gold);
    background: none;
  }
  .page-about .index-rail__link.is-active::before,
  .page-about .index-rail__link:hover::before {
    height: 18px;
  }
  .page-about .index-rail__note {
    display: block;
    margin-top: 36px;
    padding-top: 18px;
    border-top: 1px solid rgba(138, 140, 137, 0.35);
  }
  .page-about .index-rail__note p {
    font-family: var(--font-mono);
    font-size: 11px;
    letter-spacing: 0.12em;
    text-transform: uppercase;
    color: var(--stone);
    margin: 0 0 12px;
  }
  .page-about .index-rail__note a {
    display: block;
    color: var(--ink);
    text-decoration: none;
    font-size: 13px;
    padding: 6px 0;
    transition: color 0.2s ease;
  }
  .page-about .index-rail__note a:hover {
    color: var(--gold);
  }
  .page-about .about-story {
    padding: 72px 0 96px;
  }
  .page-about .about-section {
    margin-bottom: 96px;
  }
  .page-about .about-quote {
    font-size: 20px;
  }
  .page-about .about-cta {
    margin-top: 40px;
  }
}