.page-about {
  --about-gutter: clamp(16px, 4vw, 48px);
  background-color: var(--color-bg);
  background-image:
    linear-gradient(rgba(176, 184, 201, 0.04) 1px, transparent 1px),
    linear-gradient(90deg, rgba(176, 184, 201, 0.04) 1px, transparent 1px);
  background-size: 40px 40px;
  color: var(--color-text);
  font-family: var(--font-body);
  line-height: 1.75;
}

.page-about img {
  max-width: 100%;
  height: auto;
  display: block;
}

.page-about a {
  color: var(--color-accent-hover);
  text-underline-offset: 4px;
  transition: color var(--transition-fast);
}

.page-about a:hover,
.page-about a:focus-visible {
  color: var(--color-accent);
}

/* 面包屑 */
.page-about .breadcrumb {
  display: flex;
  flex-wrap: wrap;
  font-size: 0.875rem;
  margin-bottom: 40px;
}

.page-about .breadcrumb__list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  list-style: none;
  padding: 0;
  margin: 0;
}

.page-about .breadcrumb__link {
  color: var(--color-text-secondary);
  text-decoration: none;
}

.page-about .breadcrumb__item--current {
  color: var(--color-data-soft);
  font-family: var(--font-data);
}

/* Hero */
.page-about .about-hero {
  position: relative;
  border-bottom: 1px solid var(--color-border);
  background:
    linear-gradient(125deg, rgba(255, 107, 53, 0.22) 0%, transparent 36%),
    linear-gradient(300deg, rgba(57, 255, 20, 0.08) 0%, transparent 34%);
  overflow: hidden;
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  right: -120px;
  top: 40px;
  width: 420px;
  height: 420px;
  background: linear-gradient(135deg, rgba(255, 107, 53, 0.08), rgba(57, 255, 20, 0.05));
  transform: rotate(18deg);
  border: 1px solid var(--color-border);
  pointer-events: none;
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 4px;
  background: linear-gradient(90deg, var(--color-accent), var(--color-data));
  opacity: 0.9;
}

.page-about .about-hero__inner {
  position: relative;
  z-index: 1;
  max-width: var(--container-max);
  margin-inline: auto;
  padding: clamp(2rem, 5vw, 4.5rem) var(--about-gutter) clamp(3rem, 6vw, 5rem);
}

.page-about .about-hero__grid {
  display: grid;
  gap: 36px;
  align-items: start;
}

.page-about .about-hero__label {
  display: inline-block;
  font-family: var(--font-data);
  font-size: 0.875rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--color-data-soft);
  border: 1px solid rgba(57, 255, 20, 0.4);
  padding: 6px 10px;
  margin: 0 0 20px;
}

.page-about .about-hero__title {
  font-family: var(--font-heading);
  font-size: clamp(2.75rem, 9vw, 6.5rem);
  line-height: 0.95;
  text-transform: uppercase;
  letter-spacing: 0.01em;
  margin: 0 0 18px;
  color: var(--color-text);
  text-shadow: 6px 6px 0 rgba(255, 107, 53, 0.16);
  padding-bottom: 18px;
  position: relative;
}

.page-about .about-hero__title::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 0;
  width: clamp(80px, 18vw, 180px);
  height: 6px;
  background: var(--color-accent);
  box-shadow: 0 0 12px rgba(255, 107, 53, 0.5);
}

.page-about .about-hero__lead {
  font-size: 1.0625rem;
  max-width: 54ch;
  color: var(--color-text-secondary);
  margin-bottom: 28px;
}

.page-about .about-hero__side {
  display: grid;
  gap: 16px;
  align-content: start;
}

.page-about .about-hero__card {
  position: relative;
  background: var(--color-bg-2);
  border: 1px solid var(--color-border);
  border-left: 6px solid var(--color-accent);
  padding: 20px 18px 18px;
  display: grid;
  gap: 2px;
}

.page-about .about-hero__card:nth-child(2) {
  margin-left: 24px;
  border-left-color: var(--color-data);
}

.page-about .about-hero__card:nth-child(3) {
  margin-left: 42px;
  border-left-color: var(--color-data-soft);
}

.page-about .about-hero__card-kicker {
  font-family: var(--font-data);
  font-size: 0.8rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-text-secondary);
}

.page-about .about-hero__card-value {
  font-family: var(--font-data);
  font-size: 1.75rem;
  font-weight: 800;
  color: var(--color-text);
}

.page-about .about-hero__card-desc {
  font-size: 0.875rem;
  color: var(--color-text-secondary);
}

/* 章节通用 */
.page-about .about-chapter {
  padding: clamp(3rem, 6vw, 5rem) var(--about-gutter);
}

.page-about .about-chapter__inner {
  max-width: var(--container-max);
  margin-inline: auto;
}

.page-about .about-chapter__head {
  display: flex;
  align-items: flex-start;
  gap: 16px;
  margin-bottom: 32px;
}

.page-about .about-chapter__no {
  flex: 0 0 auto;
  font-family: var(--font-data);
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--color-accent);
  border: 1px solid var(--color-border-strong);
  padding: 6px 10px;
  line-height: 1;
  text-align: center;
  min-width: 44px;
}

.page-about .about-chapter__title {
  font-family: var(--font-heading);
  font-size: clamp(2rem, 5vw, 3.5rem);
  line-height: 1.05;
  text-transform: uppercase;
  margin: 0;
  padding-bottom: 14px;
  position: relative;
  color: var(--color-text);
}

.page-about .about-chapter__title::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 0;
  width: 64px;
  height: 5px;
  background: var(--color-accent);
}

.page-about .about-chapter__body {
  font-size: 1.0625rem;
  max-width: 72ch;
}

.page-about .about-chapter__body p + p {
  margin-top: 16px;
}

.page-about .about-scale,
.page-about .about-milestones,
.page-about .about-ecosystem {
  background: rgba(19, 39, 71, 0.32);
  border-block: 1px solid var(--color-border);
}

/* 02 数据规模 */
.page-about .about-scale__intro {
  max-width: 68ch;
  font-size: 1.0625rem;
}

.page-about .about-scale__layout {
  display: grid;
  gap: 28px;
  align-items: start;
}

.page-about .about-scale__content {
  display: grid;
  gap: 28px;
}

.page-about .about-scale__metrics {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 14px;
}

.page-about .about-metric-card {
  position: relative;
  background: var(--color-bg-2);
  border: 1px solid var(--color-border);
  border-top: 4px solid var(--color-accent);
  padding: 18px 14px 14px;
  display: grid;
  gap: 4px;
  transition: border-color var(--transition-medium), background-color var(--transition-medium), transform var(--transition-medium);
}

.page-about .about-metric-card:hover,
.page-about .about-metric-card:focus-within {
  border-color: var(--color-data-soft);
  background-color: rgba(19, 39, 71, 0.65);
  transform: translateY(-4px);
}

.page-about .about-metric-card__num {
  font-family: var(--font-data);
  font-size: clamp(1.5rem, 4vw, 2.25rem);
  font-weight: 800;
  color: var(--color-data);
  transition: color var(--transition-fast), text-shadow var(--transition-medium);
}

.page-about .about-metric-card:hover .about-metric-card__num,
.page-about .about-metric-card:focus-within .about-metric-card__num {
  color: var(--color-text);
  text-shadow: 0 0 18px rgba(57, 255, 20, 0.55);
}

.page-about .about-metric-card__unit {
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--color-text);
}

.page-about .about-metric-card__desc {
  font-size: 0.85rem;
  color: var(--color-text-secondary);
  margin: 0;
}

.page-about .about-scale__figure {
  margin: 0;
  border: 1px solid var(--color-border);
  background: var(--color-bg-deep);
  align-self: stretch;
  display: flex;
  align-items: center;
  justify-content: center;
}

.page-about .about-scale__img {
  width: 100%;
}

/* 03 统计资料 */
.page-about .about-stats__layout {
  display: grid;
  gap: 36px;
}

.page-about .about-stats__text {
  display: grid;
  gap: 16px;
  max-width: 80ch;
  font-size: 1.0625rem;
}

.page-about .about-stats__tabs {
  margin-top: 28px;
  border: 1px solid var(--color-border);
  background: var(--color-bg-2);
}

.page-about .about-stats__panel {
  padding: 24px;
}

.page-about .about-stats__side {
  border-left: 1px solid var(--color-border-strong);
  padding-left: 20px;
}

.page-about .about-stats__card {
  background: var(--color-bg-2);
  border: 1px solid var(--color-border);
  padding: 22px 18px;
  border-bottom: 4px solid var(--color-data);
}

.page-about .about-stats__card-title {
  font-family: var(--font-heading);
  font-size: 1.25rem;
  text-transform: uppercase;
  margin: 0 0 18px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--color-border);
}

.page-about .about-stats__list {
  margin: 0;
}

.page-about .about-stats__list div {
  display: grid;
  gap: 2px;
  padding: 12px 0;
  border-bottom: 1px solid rgba(176, 184, 201, 0.12);
}

.page-about .about-stats__list dt {
  font-family: var(--font-data);
  font-size: 0.875rem;
  font-weight: 700;
  color: var(--color-accent);
}

.page-about .about-stats__list dd {
  margin: 0;
  font-size: 0.875rem;
  color: var(--color-text-secondary);
}

/* 04 里程碑 */
.page-about .about-milestones__intro {
  display: grid;
  gap: 24px;
  margin-bottom: 48px;
}

.page-about .about-milestones__intro p {
  max-width: 68ch;
}

.page-about .about-milestones__figure {
  margin: 0;
  border: 1px solid var(--color-border);
  background: var(--color-bg-deep);
}

.page-about .about-milestones__img {
  width: 100%;
}

.page-about .about-milestones__timeline {
  position: relative;
  padding-left: 28px;
}

.page-about .about-milestones__timeline::before {
  content: "";
  position: absolute;
  left: 8px;
  top: 8px;
  bottom: 8px;
  width: 2px;
  background: var(--color-data);
  opacity: 0.5;
}

.page-about .about-milestone {
  position: relative;
  margin-bottom: 24px;
  background: var(--color-bg-2);
  border: 1px solid var(--color-border);
  padding: 22px 18px;
  display: grid;
  gap: 6px;
  transition: border-color var(--transition-medium), transform var(--transition-medium);
}

.page-about .about-milestone:hover,
.page-about .about-milestone:focus-within {
  border-color: var(--color-data-soft);
  transform: translateY(-3px);
}

.page-about .about-milestone__dot {
  position: absolute;
  left: -28px;
  top: 26px;
  width: 12px;
  height: 12px;
  background: var(--color-data);
  box-shadow: 0 0 0 5px rgba(57, 255, 20, 0.18);
}

.page-about .about-milestone__year {
  font-family: var(--font-data);
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--color-accent);
}

.page-about .about-milestone__body h3 {
  font-family: var(--font-heading);
  font-size: 1.25rem;
  text-transform: uppercase;
  margin: 0;
}

.page-about .about-milestone__body p {
  margin: 6px 0 0;
  color: var(--color-text-secondary);
  font-size: 0.95rem;
}

/* 05 团队 */
.page-about .about-team__layout {
  display: grid;
  gap: 28px;
  align-items: center;
}

.page-about .about-team__content p {
  max-width: 62ch;
}

.page-about .about-team__creds {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  padding: 0;
  margin: 24px 0 0;
}

.page-about .about-team__creds li {
  position: relative;
  border: 1px solid var(--color-border-strong);
  padding: 10px 14px 10px 30px;
  font-size: 0.9rem;
  color: var(--color-text);
}

.page-about .about-team__creds li::before {
  content: "";
  position: absolute;
  left: 12px;
  top: 50%;
  width: 8px;
  height: 8px;
  background: var(--color-data);
  transform: translateY(-50%);
}

.page-about .about-team__figure {
  margin: 0;
  border: 1px solid var(--color-border);
  background: var(--color-bg-deep);
}

.page-about .about-team__img {
  width: 100%;
}

/* 06 合作生态 */
.page-about .about-ecosystem__grid {
  display: grid;
  gap: 20px;
}

.page-about .about-ecosystem__card {
  background: var(--color-bg-2);
  border: 1px solid var(--color-border);
  padding: 24px 20px;
}

.page-about .about-ecosystem__card h3 {
  font-family: var(--font-heading);
  font-size: 1.3rem;
  text-transform: uppercase;
  margin: 0 0 12px;
}

.page-about .about-ecosystem__card p {
  margin: 0;
  color: var(--color-text-secondary);
}

.page-about .about-ecosystem__card--accent {
  border-color: var(--color-accent);
  background: linear-gradient(135deg, rgba(255, 107, 53, 0.18), rgba(19, 39, 71, 0.6));
}

.page-about .about-ecosystem__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 20px;
}

.page-about .about-ecosystem__links {
  margin-top: 28px;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  align-items: center;
  font-size: 0.95rem;
  color: var(--color-text-secondary);
}

.page-about .about-ecosystem__links a {
  color: var(--color-data-soft);
  text-decoration: none;
}

.page-about .about-ecosystem__links a:hover {
  text-decoration: underline;
}

/* 底部更多 */
.page-about .about-more {
  max-width: var(--container-max);
  margin-inline: auto;
  padding: 48px var(--about-gutter) 88px;
  display: grid;
  gap: 24px;
  border-top: 1px solid var(--color-border);
}

.page-about .about-more__text h2 {
  font-family: var(--font-heading);
  font-size: clamp(1.75rem, 4vw, 2.5rem);
  text-transform: uppercase;
  margin: 0 0 12px;
  position: relative;
  padding-bottom: 12px;
}

.page-about .about-more__text h2::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 0;
  width: 48px;
  height: 4px;
  background: var(--color-accent);
}

.page-about .about-more__text p {
  max-width: 60ch;
  margin: 0;
  color: var(--color-text-secondary);
}

.page-about .about-more__links {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  align-items: center;
}

/* 桌面与平板增强 */
@media (min-width: 720px) {
  .page-about .about-hero__grid {
    grid-template-columns: 1.15fr 0.85fr;
    gap: 48px;
  }

  .page-about .about-hero__side {
    margin-top: 32px;
  }

  .page-about .about-scale__layout {
    grid-template-columns: 1.1fr 0.9fr;
    gap: 32px;
  }

  .page-about .about-scale__figure {
    min-height: 280px;
  }

  .page-about .about-stats__layout {
    grid-template-columns: 1.3fr 0.7fr;
    gap: 28px;
    align-items: start;
  }

  .page-about .about-team__layout {
    grid-template-columns: 1fr 0.9fr;
    gap: 36px;
  }

  .page-about .about-milestones__intro {
    grid-template-columns: 1fr 0.8fr;
    align-items: center;
    gap: 40px;
  }

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

  .page-about .about-ecosystem__card--accent {
    grid-column: 1 / -1;
  }

  .page-about .about-more {
    grid-template-columns: 1fr auto;
    align-items: center;
  }
}

@media (min-width: 980px) {
  .page-about .about-ecosystem__grid {
    grid-template-columns: repeat(3, 1fr);
  }

  .page-about .about-ecosystem__card--accent {
    grid-column: auto;
  }

  /* 里程碑交替布局 */
  .page-about .about-milestones__timeline {
    padding-left: 0;
  }

  .page-about .about-milestones__timeline::before {
    left: 50%;
    transform: translateX(-50%);
  }

  .page-about .about-milestone {
    width: calc(50% - 24px);
    margin-bottom: 32px;
  }

  .page-about .about-milestone:nth-child(odd) {
    margin-right: calc(50% + 24px);
    text-align: right;
    border-right: 4px solid var(--color-data);
  }

  .page-about .about-milestone:nth-child(even) {
    margin-left: calc(50% + 24px);
    border-left: 4px solid var(--color-data);
  }

  .page-about .about-milestone:nth-child(odd) .about-milestone__dot {
    left: auto;
    right: -32px;
  }

  .page-about .about-milestone:nth-child(even) .about-milestone__dot {
    left: -32px;
  }

  .page-about .about-milestone__dot {
    top: 28px;
  }

  .page-about .about-milestone:nth-child(odd) .about-milestone__body p {
    margin-left: auto;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-metric-card,
  .page-about .about-milestone {
    transition: none;
    transform: none;
  }
}