.page-about {
  --ab-rail-w: 208px;
  --ab-gap: 28px;
  --ab-num-font: var(--font-mono);
  position: relative;
  background: var(--ink);
  color: var(--white);
  overflow-x: hidden;
}

/* ============ 首屏 ============ */
.page-about .about-intro {
  position: relative;
  padding: 40px 0 44px;
  border-bottom: 1px solid var(--line);
  overflow: hidden;
}

.page-about .about-intro::before {
  content: "";
  position: absolute;
  top: -160px;
  right: -120px;
  width: 520px;
  height: 420px;
  background: radial-gradient(circle at 50% 50%, rgba(33, 182, 232, 0.20), transparent 68%);
  pointer-events: none;
}

.page-about .about-intro::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--blue), var(--cyan) 42%, transparent 92%);
  opacity: 0.85;
}

.page-about .about-intro .breadcrumb {
  margin-bottom: 26px;
  font-size: 13px;
}

.page-about .about-intro__grid {
  display: grid;
  gap: var(--ab-gap);
}

.page-about .about-intro__kicker {
  margin: 0 0 14px;
  font-family: var(--font-cond);
  font-size: 13px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--cyan);
  padding-left: 12px;
  border-left: 2px solid var(--blue);
  line-height: 1.2;
}

.page-about .about-intro__title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(28px, 7vw, 52px);
  line-height: 1.08;
  letter-spacing: -0.02em;
  color: var(--white);
}

.page-about .about-intro__lede {
  margin: 0;
  font-size: 15px;
  line-height: 1.85;
  color: rgba(244, 247, 250, 0.80);
  max-width: 60ch;
}

.page-about .intro-facts {
  list-style: none;
  margin: 32px 0 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background-color: var(--line);
  border: 1px solid var(--line);
}

.page-about .intro-facts__item {
  background: var(--ink);
  padding: 18px 16px;
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.page-about .intro-facts__figure {
  font-family: var(--ab-num-font);
  font-size: clamp(26px, 6vw, 40px);
  line-height: 1;
  color: var(--cyan);
  letter-spacing: -0.02em;
}

.page-about .intro-facts__figure--mark {
  color: var(--orange);
}

.page-about .intro-facts__label {
  font-size: 13px;
  color: var(--grey);
  line-height: 1.5;
}

/* ============ 主体：左刻度 + 右长文 ============ */
.page-about .about-body {
  padding: 0 0 48px;
}

.page-about .about-body__grid {
  display: grid;
  gap: 8px;
}

/* --- 左侧阶段刻度 --- */
.page-about .about-rail {
  overflow-x: auto;
  overflow-y: hidden;
  -webkit-overflow-scrolling: touch;
  scrollbar-width: thin;
  padding: 18px 0 6px;
  border-bottom: 1px solid var(--line);
}

.page-about .rail-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  gap: 8px;
  min-width: max-content;
}

.page-about .rail-item a {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 7px 12px;
  font-size: 13px;
  line-height: 1.2;
  color: var(--grey);
  text-decoration: none;
  border: 1px solid var(--glass);
  background: var(--ink-2);
  white-space: nowrap;
  transition: color 180ms var(--ease), border-color 180ms var(--ease), background-color 180ms var(--ease);
}

.page-about .rail-item__dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  border: 1px solid var(--blue);
  background: transparent;
  flex: none;
  transition: background-color 180ms var(--ease), box-shadow 180ms var(--ease);
}

.page-about .rail-item a:hover,
.page-about .rail-item a:focus-visible {
  color: var(--white);
  border-color: rgba(75, 240, 208, 0.55);
  background: var(--ink-3);
  outline: none;
}

.page-about .rail-item a:hover .rail-item__dot,
.page-about .rail-item a:focus-visible .rail-item__dot {
  background: var(--cyan);
  box-shadow: 0 0 10px rgba(75, 240, 208, 0.7);
}

/* --- 右侧内容 --- */
.page-about .about-content {
  min-width: 0;
}

.page-about .ab-section {
  padding: 40px 0 36px;
  border-top: 1px solid var(--line);
}

.page-about .ab-section:first-child {
  border-top: 0;
  padding-top: 32px;
}

.page-about .ab-section__index {
  margin: 0 0 10px;
  font-family: var(--font-cond);
  font-size: 13px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--blue);
}

.page-about .ab-section__title {
  margin: 0 0 20px;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(22px, 5vw, 32px);
  line-height: 1.22;
  letter-spacing: -0.02em;
  color: var(--white);
}

.page-about .ab-section p {
  margin: 0 0 1.15em;
  font-size: 15px;
  line-height: 1.85;
  color: rgba(244, 247, 250, 0.82);
  max-width: 68ch;
}

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

.page-about .ab-section a {
  color: var(--blue);
  text-decoration: none;
  border-bottom: 1px solid rgba(33, 182, 232, 0.4);
  transition: color 160ms var(--ease), border-color 160ms var(--ease);
}

.page-about .ab-section a:hover,
.page-about .ab-section a:focus-visible {
  color: var(--cyan);
  border-color: var(--cyan);
  outline: none;
}

.page-about .ab-num {
  font-family: var(--ab-num-font);
  color: var(--cyan);
  font-size: 0.95em;
  letter-spacing: -0.01em;
}

.page-about .ab-num--alert {
  color: var(--orange);
  border-bottom: 1px solid rgba(255, 90, 43, 0.45);
  padding-bottom: 1px;
}

/* --- 引文块 --- */
.page-about .ab-quote {
  margin: 26px 0 4px;
  padding: 18px 20px;
  border: 1px solid var(--glass);
  border-left: 2px solid var(--cyan);
  background: linear-gradient(90deg, rgba(75, 240, 208, 0.07), rgba(14, 22, 32, 0.5));
}

.page-about .ab-quote p {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 17px;
  line-height: 1.65;
  letter-spacing: -0.01em;
  color: var(--white);
  max-width: 40ch;
}

/* --- 图片 --- */
.page-about .ab-figure {
  margin: 0 0 26px;
  border: 1px solid var(--glass);
  background: var(--ink-2);
  box-shadow: var(--shadow-card);
  overflow: hidden;
}

.page-about .ab-figure img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  object-fit: cover;
  aspect-ratio: 3 / 2;
}

.page-about .ab-figure--wide img {
  aspect-ratio: 2 / 1;
}

.page-about .ab-figure--banner img {
  aspect-ratio: 4 / 1;
}

.page-about .ab-figure figcaption {
  padding: 11px 14px;
  font-size: 13px;
  line-height: 1.6;
  color: var(--grey);
  border-top: 1px solid var(--line);
}

/* --- 流程四步 --- */
.page-about .flow {
  list-style: none;
  margin: 24px 0 26px;
  padding: 0;
  display: grid;
  gap: 10px;
}

.page-about .flow-step {
  position: relative;
  padding: 16px 14px 15px;
  border: 1px solid var(--glass);
  border-top: 2px solid rgba(33, 182, 232, 0.55);
  background: linear-gradient(180deg, rgba(33, 182, 232, 0.09), rgba(14, 22, 32, 0.92));
  transition: transform 180ms var(--ease), border-color 180ms var(--ease);
}

.page-about .flow-step:hover {
  transform: translateY(-4px);
  border-color: rgba(75, 240, 208, 0.5);
  border-top-color: var(--cyan);
}

.page-about .flow-step__no {
  display: block;
  font-family: var(--ab-num-font);
  font-size: 12px;
  color: var(--blue);
  letter-spacing: 0.1em;
  margin-bottom: 8px;
}

.page-about .flow-step__name {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 17px;
  line-height: 1.3;
  letter-spacing: -0.01em;
  color: var(--white);
}

.page-about .flow-step__role {
  margin: 0 0 8px;
  font-family: var(--ab-num-font);
  font-size: 12px;
  line-height: 1.5;
  color: var(--cyan);
}

.page-about .flow-step__desc {
  margin: 0;
  font-size: 13px;
  line-height: 1.7;
  color: var(--grey);
  max-width: none;
}

/* --- 横向主题带 --- */
.page-about .ab-band {
  margin: 0;
  padding: 26px 0;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  background: linear-gradient(100deg, rgba(33, 182, 232, 0.14), rgba(14, 22, 32, 0.75) 46%, rgba(75, 240, 208, 0.12));
}

.page-about .ab-band--coverage {
  background: linear-gradient(100deg, rgba(30, 139, 255, 0.16), rgba(14, 22, 32, 0.75) 46%, rgba(43, 227, 164, 0.16));
}

.page-about .band-stats {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 20px 16px;
  grid-template-columns: repeat(auto-fit, minmax(112px, 1fr));
}

.page-about .band-stat {
  min-width: 0;
}

.page-about .band-stat__figure {
  display: block;
  font-family: var(--ab-num-font);
  font-size: clamp(24px, 6vw, 38px);
  line-height: 1;
  letter-spacing: -0.03em;
  color: var(--cyan);
  padding-bottom: 8px;
  border-bottom: 2px solid rgba(75, 240, 208, 0.35);
}

.page-about .band-stat__label {
  display: block;
  margin-top: 9px;
  font-size: 13px;
  line-height: 1.45;
  color: var(--grey);
}

/* --- 团队网格 --- */
.page-about .team-grid {
  display: grid;
  gap: 1px;
  background-color: var(--line);
  border: 1px solid var(--line);
  margin: 24px 0 26px;
}

.page-about .team-card {
  background: var(--ink);
  padding: 22px 18px 20px;
  transition: background-color 180ms var(--ease);
}

.page-about .team-card:hover {
  background: var(--ink-2);
}

.page-about .team-card__num {
  display: block;
  font-family: var(--ab-num-font);
  font-size: 34px;
  line-height: 1;
  letter-spacing: -0.03em;
  color: var(--blue);
  margin-bottom: 12px;
}

.page-about .team-card__role {
  margin: 0 0 10px;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 17px;
  line-height: 1.3;
  letter-spacing: -0.01em;
  color: var(--white);
}

.page-about .team-card p {
  margin: 0;
  font-size: 13px;
  line-height: 1.75;
  color: var(--grey);
  max-width: none;
}

/* --- 覆盖标签 --- */
.page-about .coverage-tags {
  list-style: none;
  margin: 22px 0 24px;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

/* --- 阶段展牌 --- */
.page-about .stages {
  list-style: none;
  margin: 24px 0 26px;
  padding: 0;
  display: grid;
  gap: 12px;
}

.page-about .stage {
  display: grid;
  grid-template-columns: 54px minmax(0, 1fr);
  align-items: stretch;
  border: 1px solid var(--glass);
  border-left: 2px solid var(--blue);
  background: var(--ink-2);
  transition: border-left-color 180ms var(--ease), background-color 180ms var(--ease);
}

.page-about .stage:hover {
  border-left-color: var(--cyan);
  background: var(--ink-3);
}

.page-about .stage__no {
  display: grid;
  place-items: center;
  font-family: var(--ab-num-font);
  font-size: 15px;
  letter-spacing: 0.06em;
  color: var(--cyan);
  background: rgba(33, 182, 232, 0.10);
  border-right: 1px solid var(--line);
  padding: 16px 0;
}

.page-about .stage__body {
  padding: 16px 16px 18px;
  min-width: 0;
}

.page-about .stage__name {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 17px;
  line-height: 1.32;
  letter-spacing: -0.01em;
  color: var(--white);
}

.page-about .stage__body p {
  margin: 0;
  font-size: 13px;
  line-height: 1.75;
  color: var(--grey);
  max-width: none;
}

/* --- 合作卡片 --- */
.page-about .partner-grid {
  display: grid;
  gap: 12px;
  margin: 24px 0 26px;
}

.page-about .partner-card {
  padding: 20px 18px 22px;
  border: 1px solid var(--glass);
  background: var(--ink-2);
  transition: transform 180ms var(--ease), border-color 180ms var(--ease);
}

.page-about .partner-card:hover {
  transform: translateY(-4px);
  border-color: rgba(33, 182, 232, 0.55);
}

.page-about .partner-card__badge {
  display: inline-block;
  margin-bottom: 14px;
  padding: 4px 10px;
  font-family: var(--font-cond);
  font-size: 12px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--ink);
  background: var(--cyan);
}

.page-about .partner-card__title {
  margin: 0 0 10px;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 17px;
  line-height: 1.32;
  letter-spacing: -0.01em;
  color: var(--white);
}

.page-about .partner-card p {
  margin: 0;
  font-size: 13px;
  line-height: 1.78;
  color: var(--grey);
  max-width: none;
}

/* --- 收尾章节 --- */
.page-about .ab-section--last {
  border-bottom: 1px solid var(--line);
}

/* ============ 平板 ============ */
@media (min-width: 640px) {
  .page-about .about-intro {
    padding: 52px 0 52px;
  }

  .page-about .intro-facts {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    margin-top: 38px;
  }

  .page-about .flow {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 12px;
  }

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

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

  .page-about .about-rail {
    padding-bottom: 10px;
  }
}

/* ============ 桌面：左右分屏 ============ */
@media (min-width: 960px) {
  .page-about .about-intro {
    padding: 64px 0 60px;
  }

  .page-about .about-intro__grid {
    grid-template-columns: minmax(0, 1.08fr) minmax(0, 0.92fr);
    gap: 56px;
    align-items: end;
  }

  .page-about .about-intro__lede {
    font-size: 16px;
  }

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

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

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

  .page-about .ab-section {
    padding: 56px 0 48px;
  }

  .page-about .ab-section p {
    font-size: 16px;
  }

  .page-about .stage {
    grid-template-columns: 64px minmax(0, 1fr);
  }
}

@media (min-width: 1040px) {
  .page-about .about-body {
    padding-bottom: 72px;
  }

  .page-about .about-body__grid {
    grid-template-columns: var(--ab-rail-w) minmax(0, 1fr);
    gap: 56px;
  }

  .page-about .about-rail {
    position: sticky;
    top: 92px;
    align-self: start;
    max-height: calc(100vh - 130px);
    overflow: visible;
    padding: 44px 0 0;
    border-bottom: 0;
  }

  .page-about .rail-list {
    display: block;
    min-width: 0;
    position: relative;
    padding-left: 0;
  }

  .page-about .rail-list::before {
    content: "";
    position: absolute;
    left: 4px;
    top: 10px;
    bottom: 10px;
    width: 1px;
    background: linear-gradient(180deg, rgba(33, 182, 232, 0.75), rgba(33, 182, 232, 0.06));
  }

  .page-about .rail-item {
    margin-bottom: 4px;
  }

  .page-about .rail-item a {
    display: flex;
    width: 100%;
    border-color: transparent;
    background: transparent;
    padding: 7px 10px 7px 0;
    gap: 12px;
  }

  .page-about .rail-item a:hover,
  .page-about .rail-item a:focus-visible {
    border-color: transparent;
    background: transparent;
  }

  .page-about .rail-item__dot {
    position: relative;
    z-index: 1;
    margin-left: 0;
    width: 9px;
    height: 9px;
    background: var(--ink);
  }

  .page-about .rail-item__text {
    font-size: 13px;
    letter-spacing: 0.02em;
  }

  .page-about .ab-section:first-child {
    padding-top: 44px;
  }
}

/* ============ 大屏 ============ */
@media (min-width: 1280px) {
  .page-about {
    --ab-rail-w: 232px;
  }

  .page-about .about-intro__grid {
    gap: 72px;
  }
}

/* ============ 降低动效 ============ */
@media (prefers-reduced-motion: reduce) {
  .page-about .flow-step,
  .page-about .partner-card,
  .page-about .stage,
  .page-about .rail-item a,
  .page-about .rail-item__dot {
    transition: none;
  }

  .page-about .flow-step:hover,
  .page-about .partner-card:hover {
    transform: none;
  }
}