.page-about {
  --about-year-size: clamp(2.4rem, 5vw, 3.4rem);
  --about-card-pad: clamp(1.25rem, 3vw, 2.25rem);
  background: var(--color-bg);
  color: var(--color-text);
  overflow-x: hidden;
  position: relative;
}

/* 面包屑 */
.page-about .about-crumb {
  max-width: var(--container-max);
  margin: 18px auto 0;
  padding: 0 20px;
  font-size: 0.875rem;
  color: var(--color-text-dim);
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  align-items: center;
  font-family: var(--font-body);
}
.page-about .about-crumb a {
  color: var(--color-accent-blue);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: border-color 0.2s ease, color 0.2s ease;
}
.page-about .about-crumb a:hover {
  color: var(--color-accent-orange);
  border-bottom-color: var(--color-accent-orange);
}
.page-about .about-crumb-sep {
  color: var(--color-divider);
}

/* 英雄区 */
.page-about .about-hero {
  display: grid;
  grid-template-columns: 1fr;
  gap: 28px;
  padding-top: 32px;
  padding-bottom: 48px;
}
.page-about .about-eyebrow {
  font-family: var(--font-mono);
  font-size: 0.875rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--color-accent-blue);
  margin-bottom: 12px;
  border-bottom: 1px solid var(--color-divider);
  padding-bottom: 8px;
}
.page-about .about-hero h1 {
  font-family: var(--font-head);
  font-weight: 900;
  font-size: clamp(2.5rem, 6.4vw, 4.5rem);
  line-height: 1.12;
  margin: 0 0 20px;
  letter-spacing: -0.02em;
}
.page-about .about-hero-subline {
  display: block;
  color: var(--color-accent-orange);
  font-size: clamp(1.2rem, 3vw, 2rem);
  font-weight: 700;
  margin-top: 4px;
}
.page-about .about-lead {
  max-width: 560px;
  font-size: clamp(1rem, 1.6vw, 1.125rem);
  line-height: 1.8;
  color: var(--color-text-dim);
  border-left: 4px solid var(--color-accent-orange);
  padding-left: 16px;
  margin: 0;
}
.page-about .about-hero-aside {
  background: var(--color-bg-surface);
  border: 3px solid var(--color-divider);
  box-shadow: var(--shadow-hard);
  clip-path: polygon(0 0, 100% 4%, 100% 100%, 0 88%);
  padding: 28px 24px 32px;
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
}
.page-about .about-hero-stat {
  display: flex;
  flex-direction: column;
}
.page-about .ah-num {
  font-family: var(--font-mono);
  font-size: clamp(2rem, 5vw, 3.2rem);
  font-weight: 700;
  color: var(--color-text);
  line-height: 1;
}
.page-about .ah-label {
  font-size: 0.875rem;
  color: var(--color-text-dim);
  margin-top: 8px;
}

/* 起点与使命 */
.page-about .about-origin {
  padding-top: 24px;
  padding-bottom: 56px;
}
.page-about .about-origin-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 32px;
}
.page-about .about-origin-text h2 {
  font-size: clamp(1.75rem, 3.6vw, 2.75rem);
  font-weight: 900;
  margin: 0 0 16px;
}
.page-about .about-origin-text p {
  font-size: 1rem;
  line-height: 1.85;
  color: var(--color-text-dim);
  margin: 0 0 14px;
}
.page-about .about-origin-text strong {
  color: var(--color-accent-orange);
  font-weight: 600;
}
.page-about .about-origin-aside {
  display: flex;
  justify-content: flex-start;
}
.page-about .about-origin-card {
  position: relative;
  border: 3px solid var(--color-divider);
  background: var(--color-bg-surface);
  padding: 28px 24px 24px;
  box-shadow: var(--shadow-hard);
  max-width: 280px;
  width: 100%;
}
.page-about .about-origin-card::before {
  content: "";
  position: absolute;
  top: -3px;
  right: -3px;
  width: 48px;
  height: 48px;
  background: var(--color-accent-orange);
  clip-path: polygon(100% 0, 100% 100%, 0 0);
}
.page-about .about-origin-card-year {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(3rem, 8vw, 4.5rem);
  font-weight: 700;
  color: var(--color-text);
  line-height: 1;
}
.page-about .about-origin-card-tag {
  display: inline-block;
  margin-top: 12px;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-accent-orange);
  border: 1px solid var(--color-accent-orange);
  padding: 2px 8px;
}
.page-about .about-origin-card-domain,
.page-about .about-origin-card-icp {
  font-family: var(--font-mono);
  font-size: 0.875rem;
  color: var(--color-text-dim);
  margin: 12px 0 0;
  word-break: break-all;
}
.page-about .about-origin-metrics {
  margin-top: 32px;
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
}

/* 指标卡 */
.page-about .about-metric-card {
  border: 3px solid var(--color-divider);
  background: var(--color-bg-surface);
  padding: 20px 16px;
  box-shadow: var(--shadow-hard);
  text-align: center;
  transition: border-color 0.2s ease, transform 0.2s ease;
}
.page-about .about-metric-card:hover {
  border-color: var(--color-accent-blue);
  transform: translate(-2px, -2px);
}
.page-about .am-v {
  font-family: var(--font-mono);
  font-size: clamp(1.8rem, 4vw, 2.6rem);
  font-weight: 700;
  line-height: 1;
  color: var(--color-text);
  margin: 0;
}
.page-about .am-l {
  font-size: 0.875rem;
  color: var(--color-text-dim);
  margin: 8px 0 0;
}

/* 里程碑 */
.page-about .about-milestone {
  background: var(--color-bg-deep);
  padding-top: 64px;
  padding-bottom: 72px;
  position: relative;
}
.page-about .about-milestone::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image: radial-gradient(var(--color-divider) 1px, transparent 1px);
  background-size: 26px 26px;
  opacity: 0.35;
  pointer-events: none;
}
.page-about .about-milestone .container {
  position: relative;
}
.page-about .about-sec-head {
  margin-bottom: 40px;
  max-width: 720px;
}
.page-about .about-sec-code {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-accent-orange);
  border: 2px solid var(--color-accent-orange);
  padding: 4px 12px;
  transform: skewX(-8deg);
  margin-bottom: 16px;
}
.page-about .about-sec-head h2 {
  font-size: clamp(1.9rem, 4vw, 3rem);
  font-weight: 900;
  margin: 0 0 12px;
}
.page-about .about-sec-head p {
  font-size: 1rem;
  line-height: 1.8;
  color: var(--color-text-dim);
  margin: 0;
}

/* 品牌标识图 */
.page-about .about-evolution {
  margin: 0 0 40px;
}
.page-about figure {
  margin: 0;
}
.page-about figure img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
  border: 3px solid var(--color-divider);
  box-shadow: var(--shadow-hard);
  background: var(--color-bg-surface);
}
.page-about figcaption {
  padding: 10px 2px 0;
  font-size: 0.875rem;
  color: var(--color-text-dim);
}
.page-about figcaption::before {
  content: "▸ ";
  color: var(--color-accent-orange);
}

/* 时间线 */
.page-about .about-timeline {
  position: relative;
  padding-left: 44px;
  margin-top: 8px;
}
.page-about .about-timeline::before {
  content: "";
  position: absolute;
  left: 10px;
  top: 8px;
  bottom: 8px;
  width: 3px;
  background: linear-gradient(180deg, var(--color-accent-blue), var(--color-divider) 40%, var(--color-divider) 80%, var(--color-accent-orange));
}
.page-about .about-tl-item {
  position: relative;
  margin-bottom: 40px;
}
.page-about .about-tl-item::before {
  content: "";
  position: absolute;
  left: -36px;
  top: 26px;
  width: 14px;
  height: 14px;
  background: var(--color-accent-blue);
  border: 3px solid var(--color-bg);
  border-radius: 50%;
  box-shadow: var(--shadow-hard);
  box-sizing: border-box;
}
.page-about .about-tl-year {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: var(--about-year-size);
  font-weight: 700;
  color: var(--color-text);
  background: var(--color-bg-surface);
  border: 3px solid var(--color-divider);
  box-shadow: var(--shadow-hard);
  padding: 6px 14px;
  line-height: 1;
  margin-bottom: 14px;
}
.page-about .about-tl-card {
  border: 3px solid var(--color-divider);
  background: var(--color-bg-surface);
  box-shadow: var(--shadow-hard);
  padding: var(--about-card-pad);
  position: relative;
  transition: border-color 0.2s ease, box-shadow 0.2s ease, transform 0.2s ease;
}
.page-about .about-tl-card:hover {
  border-color: var(--color-accent-blue);
  box-shadow: var(--shadow-hard), var(--shadow-blue);
  transform: translate(-3px, -3px);
}
.page-about .about-tl-version {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  color: var(--color-accent-orange);
  border: 2px solid var(--color-accent-orange);
  padding: 2px 10px;
  margin-bottom: 14px;
  transition: background 0.2s ease, color 0.2s ease;
}
.page-about .about-tl-version:hover {
  background: var(--color-accent-orange);
  color: var(--color-bg-deep);
}
.page-about .about-tl-card h3 {
  font-family: var(--font-head);
  font-size: 1.25rem;
  font-weight: 800;
  margin: 0 0 10px;
}
.page-about .about-tl-card p {
  font-size: 0.9375rem;
  line-height: 1.8;
  color: var(--color-text-dim);
  margin: 0;
}

/* 团队与规模 */
.page-about .about-team {
  padding-top: 72px;
  padding-bottom: 80px;
}
.page-about .about-team .container-wide {
  max-width: calc(var(--container-max) + 140px);
  margin: 0 auto;
  padding: 0 20px;
}
.page-about .about-team-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 36px;
  align-items: start;
}
.page-about .about-team-summary {
  border-left: 4px solid var(--color-accent-blue);
  padding-left: 20px;
}
.page-about .about-team-bignum {
  font-family: var(--font-mono);
  font-size: clamp(4rem, 10vw, 6.5rem);
  font-weight: 700;
  line-height: 1;
  margin: 0 0 10px;
  color: var(--color-text);
}
.page-about .about-team-bignum span {
  color: var(--color-accent-orange);
  font-size: 0.5em;
  margin-left: 4px;
}
.page-about .about-team-desc {
  font-size: 1rem;
  line-height: 1.85;
  color: var(--color-text-dim);
  margin: 0;
  max-width: 480px;
}
.page-about .about-team-roster {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
}
.page-about .about-team-role {
  border: 3px solid var(--color-divider);
  background: var(--color-bg-surface);
  padding: 22px 20px;
  box-shadow: var(--shadow-hard);
  transition: border-color 0.2s ease, transform 0.2s ease;
}
.page-about .about-team-role:hover {
  border-color: var(--color-accent-orange);
  transform: translate(-2px, -2px);
}
.page-about .about-team-icon {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  color: var(--color-bg-deep);
  padding: 3px 10px;
  margin-bottom: 12px;
}
.page-about .about-team-icon-data {
  background: var(--color-accent-blue);
}
.page-about .about-team-icon-edit {
  background: var(--color-accent-orange);
}
.page-about .about-team-icon-video {
  background: var(--color-accent-blue-soft);
}
.page-about .about-team-role h3 {
  font-family: var(--font-head);
  font-size: 1.15rem;
  font-weight: 800;
  margin: 0 0 8px;
}
.page-about .about-team-role p {
  font-size: 0.9375rem;
  line-height: 1.8;
  color: var(--color-text-dim);
  margin: 0;
}
.page-about .about-team-figure {
  margin-top: 44px;
}

/* 资质与荣誉 */
.page-about .about-cert {
  background: var(--color-bg-deep);
  padding-top: 64px;
  padding-bottom: 72px;
  position: relative;
}
.page-about .about-cert::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: linear-gradient(90deg, var(--color-accent-blue), var(--color-accent-orange));
}
.page-about .about-cert-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 18px;
}
.page-about .about-cert-card {
  border: 3px solid var(--color-divider);
  background: var(--color-bg-surface);
  padding: 26px 22px;
  box-shadow: var(--shadow-hard);
  transition: border-color 0.2s ease, transform 0.2s ease, box-shadow 0.2s ease;
  position: relative;
}
.page-about .about-cert-card:hover {
  border-color: var(--color-accent-blue);
  box-shadow: var(--shadow-hard), var(--shadow-blue);
  transform: translate(-2px, -2px);
}
.page-about .about-cert-main {
  border-color: var(--color-accent-orange);
}
.page-about .about-cert-badge {
  display: block;
  width: fit-content;
  font-family: var(--font-mono);
  font-size: 0.875rem;
  font-weight: 700;
  color: var(--color-accent-orange);
  border: 2px solid var(--color-accent-orange);
  padding: 4px 12px;
  margin-bottom: 14px;
  transform: skewX(-8deg);
}
.page-about .about-cert-card h3 {
  font-family: var(--font-head);
  font-size: 1.2rem;
  font-weight: 800;
  margin: 0 0 10px;
}
.page-about .about-cert-card p {
  font-size: 0.9375rem;
  line-height: 1.8;
  color: var(--color-text-dim);
  margin: 0;
}
.page-about .about-cert-figure {
  margin-top: 44px;
}

/* 合作生态 */
.page-about .about-partnership {
  padding-top: 72px;
  padding-bottom: 72px;
}
.page-about .about-partnership-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 40px;
  align-items: center;
}
.page-about .about-partnership-text h2 {
  font-size: clamp(1.9rem, 4vw, 3rem);
  font-weight: 900;
  margin: 0 0 14px;
}
.page-about .about-partnership-text p {
  font-size: 1rem;
  line-height: 1.85;
  color: var(--color-text-dim);
  margin: 0 0 14px;
}
.page-about .about-partnership-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 26px;
}
.page-about .about-partnership-metrics {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
}
.page-about .amc-orange .am-v {
  color: var(--color-accent-orange);
}
.page-about .amc-blue .am-v {
  color: var(--color-accent-blue);
}

/* 联系CTA */
.page-about .about-contact-cta {
  padding-bottom: 80px;
}
.page-about .about-cta-box {
  display: flex;
  flex-direction: column;
  gap: 20px;
  align-items: flex-start;
  border: 3px solid var(--color-accent-orange);
  border-left-width: 8px;
  background: var(--color-bg-surface);
  box-shadow: var(--shadow-hard);
  padding: 28px 24px;
}
.page-about .about-cta-kicker {
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-accent-orange);
  margin: 0 0 4px;
}
.page-about .about-cta-copy p {
  margin: 0;
  font-size: 0.9375rem;
  line-height: 1.8;
  color: var(--color-text-dim);
}

/* 桌面端适配 */
@media (min-width: 900px) {
  .page-about .about-hero {
    grid-template-columns: 1.1fr 0.9fr;
    gap: 64px;
    align-items: center;
    padding-top: 48px;
    padding-bottom: 64px;
  }
  .page-about .about-hero h1 {
    font-size: clamp(3rem, 6vw, 4.5rem);
  }
  .page-about .about-hero-aside {
    grid-template-columns: repeat(2, 1fr);
    gap: 28px 24px;
    padding: 36px 32px 42px;
  }
  .page-about .about-origin-grid {
    grid-template-columns: 1.2fr 0.8fr;
    gap: 48px;
    align-items: start;
  }
  .page-about .about-origin-aside {
    justify-content: flex-end;
  }
  .page-about .about-origin-metrics {
    grid-template-columns: repeat(4, 1fr);
    gap: 20px;
    margin-top: 48px;
  }
  .page-about .about-team-grid {
    grid-template-columns: 0.9fr 1.1fr;
    gap: 56px;
  }
  .page-about .about-team-roster {
    grid-template-columns: repeat(3, 1fr);
    gap: 18px;
  }
  .page-about .about-cert-grid {
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
  }
  .page-about .about-cert-main {
    grid-column: span 2;
  }
  .page-about .about-partnership-grid {
    grid-template-columns: 1.05fr 0.95fr;
    gap: 72px;
  }
  .page-about .about-partnership-metrics {
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
  }
  .page-about .about-cta-box {
    flex-direction: row;
    justify-content: space-between;
    align-items: center;
    padding: 32px 36px;
  }

  /* 桌面端时间线：交替布局 */
  .page-about .about-timeline {
    padding-left: 0;
    position: relative;
    max-width: 1120px;
    margin-left: auto;
    margin-right: auto;
  }
  .page-about .about-timeline::before {
    content: "";
    position: absolute;
    left: 50%;
    top: 20px;
    bottom: 20px;
    width: 3px;
    transform: translateX(-50%);
    background: linear-gradient(180deg, var(--color-accent-blue), var(--color-divider) 40%, var(--color-divider) 80%, var(--color-accent-orange));
  }
  .page-about .about-tl-item {
    display: grid;
    grid-template-columns: 1fr 160px 1fr;
    align-items: start;
    column-gap: 0;
    margin-bottom: 48px;
  }
  .page-about .about-tl-item::before {
    display: none;
  }
  .page-about .about-tl-year {
    grid-column: 2;
    grid-row: 1;
    justify-self: center;
    align-self: start;
    margin-bottom: 0;
    position: relative;
    z-index: 1;
  }
  .page-about .about-tl-item:nth-child(odd) .about-tl-card {
    grid-column: 3;
    grid-row: 1;
  }
  .page-about .about-tl-item:nth-child(even) .about-tl-card {
    grid-column: 1;
    grid-row: 1;
    text-align: left;
  }
  .page-about .about-tl-card {
    margin-top: 4px;
  }
  .page-about .about-tl-card::after {
    content: "";
    position: absolute;
    top: 32px;
    width: 18px;
    height: 18px;
    background: var(--color-accent-blue);
    border: 3px solid var(--color-bg-deep);
    box-shadow: var(--shadow-hard);
    box-sizing: border-box;
    z-index: 2;
  }
  .page-about .about-tl-item:nth-child(odd) .about-tl-card::after {
    left: -51px;
  }
  .page-about .about-tl-item:nth-child(even) .about-tl-card::after {
    right: -51px;
  }
}

/* 动效降级适配 */
@media (prefers-reduced-motion: reduce) {
  .page-about .about-tl-card,
  .page-about .about-cert-card,
  .page-about .about-team-role,
  .page-about .about-metric-card,
  .page-about .about-hero-aside {
    transition: none;
  }
  .page-about .btn,
  .page-about .about-tl-version,
  .page-about .about-crumb a {
    transition: none;
  }
}