.page-about {
  --about-muted-line: rgba(212, 168, 67, 0.22);
  --about-tech-line: rgba(42, 109, 181, 0.35);
  background: var(--color-obsidian);
  color: var(--color-off-white);
  font-family: var(--font-sans);
  scroll-behavior: smooth;
}

/* 面包屑 */
.page-about__breadcrumb {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--color-muted-gray);
  margin-bottom: 1rem;
}
.page-about__breadcrumb a {
  color: var(--color-tech-blue);
  text-decoration: none;
  transition: color 0.2s;
}
.page-about__breadcrumb a:hover {
  color: var(--color-gold-bright);
  text-decoration: underline;
}

/* Hero 区 */
.page-about__hero {
  position: relative;
  padding: 3rem 0 4rem;
  overflow: hidden;
}
.page-about__hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(212, 168, 67, 0.05) 1px, transparent 1px),
    linear-gradient(90deg, rgba(212, 168, 67, 0.05) 1px, transparent 1px);
  background-size: 44px 44px;
  pointer-events: none;
}
.page-about__hero::after {
  content: '06';
  position: absolute;
  right: -0.5rem;
  bottom: 0.5rem;
  font-family: var(--font-mono);
  font-size: 10rem;
  font-weight: 700;
  line-height: 1;
  color: rgba(212, 168, 67, 0.06);
  pointer-events: none;
}
.page-about__hero-grid {
  position: relative;
  z-index: 1;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1.25rem;
  display: grid;
  gap: 2.5rem;
}
.page-about__hero-title {
  font-size: clamp(1.9rem, 1.3rem + 2vw, 3.1rem);
  font-weight: 900;
  line-height: 1.12;
  letter-spacing: -0.035em;
  margin: 1rem 0 1.25rem;
  max-width: 16em;
}
.page-about__hero-lead {
  font-size: 1rem;
  line-height: 1.9;
  color: var(--color-muted-gray);
  max-width: 58ch;
  margin-bottom: 1rem;
}
.page-about__hero-sub {
  font-size: 0.9rem;
  color: var(--color-tech-blue);
  letter-spacing: 0.02em;
  line-height: 1.8;
  max-width: 52ch;
  margin-bottom: 2rem;
}
.page-about__hero-stats {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem 2.5rem;
  margin: 0;
  padding-top: 1.5rem;
  border-top: 1px solid var(--about-muted-line);
}
.page-about__hero-stat {
  display: flex;
  flex-direction: column-reverse;
  gap: 0.15rem;
}
.page-about__hero-stat dt {
  font-size: 0.75rem;
  color: var(--color-muted-gray);
  letter-spacing: 0.12em;
}
.page-about__hero-stat dd {
  font-family: var(--font-mono);
  font-size: 1.75rem;
  font-weight: 700;
  color: var(--color-gold);
  margin: 0;
}
.page-about__hero-media {
  margin: 0;
  position: relative;
}
.page-about__hero-media::after {
  content: '';
  position: absolute;
  right: -0.75rem;
  bottom: -0.75rem;
  width: 6rem;
  height: 6rem;
  border-right: 2px solid var(--color-gold);
  border-bottom: 2px solid var(--color-gold);
  opacity: 0.5;
  z-index: -1;
}
.page-about__hero-media img {
  width: 100%;
  height: auto;
  display: block;
  clip-path: polygon(0 0, calc(100% - 1.25rem) 0, 100% 1.25rem, 100% 100%, 1.25rem 100%, 0 calc(100% - 1.25rem));
}

/* 轨道布局 */
.page-about__track {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1.25rem;
  display: block;
}
.page-about__content {
  min-width: 0;
}

/* 锚点导航 */
.page-about__anchors {
  display: flex;
  gap: 0.5rem;
  overflow-x: auto;
  padding: 0 0 1rem;
  scrollbar-width: thin;
  margin-bottom: 0.5rem;
}
.page-about__anchors::-webkit-scrollbar {
  height: 4px;
}
.page-about__anchors::-webkit-scrollbar-thumb {
  background: var(--color-gold);
}
.page-about__anchors-label {
  display: none;
}
.page-about__anchor {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.5rem 0.85rem;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  line-height: 1;
  text-decoration: none;
  color: var(--color-muted-gray);
  background: var(--color-carbon);
  border: 1px solid rgba(255, 255, 255, 0.06);
  white-space: nowrap;
  transition: color 0.2s, border-color 0.2s, background 0.2s;
}
.page-about__anchor span {
  color: var(--color-gold);
  font-size: 0.7rem;
}
.page-about__anchor:hover,
.page-about__anchor:focus-visible {
  color: var(--color-gold-bright);
  background: var(--color-graphite);
  border-color: rgba(212, 168, 67, 0.45);
}
.page-about__anchor:focus-visible {
  outline: 2px solid var(--color-gold);
  outline-offset: 2px;
}

/* 区块通用 */
.page-about__section {
  padding: 3rem 0 3.5rem;
  border-top: 1px solid rgba(255, 255, 255, 0.05);
  scroll-margin-top: calc(var(--header-height) + 1.5rem);
}
.page-about__section--data {
  background: rgba(20, 20, 28, 0.4);
  border-top-color: rgba(212, 168, 67, 0.3);
}
.page-about__section--security {
  border-top-color: rgba(42, 109, 181, 0.3);
}
.page-about__section--eco {
  background: rgba(20, 20, 28, 0.4);
  border-top-color: rgba(255, 255, 255, 0.05);
}
.page-about__section-title {
  font-size: clamp(1.4rem, 1.2rem + 0.8vw, 2rem);
  font-weight: 900;
  line-height: 1.2;
  letter-spacing: -0.025em;
  margin: 0.75rem 0 0.75rem;
}
.page-about__section-lead {
  color: var(--color-muted-gray);
  font-size: 0.95rem;
  line-height: 1.75;
  margin-bottom: 2.25rem;
  max-width: 68ch;
}

/* 时间线 */
.page-about__timeline {
  list-style: none;
  margin: 0;
  padding: 0;
  position: relative;
}
.page-about__timeline::before {
  content: '';
  position: absolute;
  left: 8px;
  top: 0.35rem;
  bottom: 0.35rem;
  width: 2px;
  background: linear-gradient(
    180deg,
    var(--color-gold) 0%,
    rgba(212, 168, 67, 0.5) 35%,
    rgba(212, 168, 67, 0.2) 70%,
    rgba(42, 109, 181, 0.5) 100%
  );
}
.page-about__milestone {
  position: relative;
  padding: 0 0 2rem 2rem;
}
.page-about__milestone::before {
  content: '';
  position: absolute;
  left: 3px;
  top: 0.3rem;
  width: 12px;
  height: 12px;
  background: var(--color-carbon);
  border: 2px solid var(--color-gold);
  transform: rotate(45deg);
  box-shadow: 0 0 0 3px rgba(212, 168, 67, 0.14);
  z-index: 1;
}
.page-about__milestone-year {
  font-family: var(--font-mono);
  font-size: 2.2rem;
  font-weight: 700;
  line-height: 1;
  color: transparent;
  -webkit-text-stroke: 1px rgba(212, 168, 67, 0.8);
  display: block;
  margin-bottom: 0.65rem;
}
.page-about__milestone-body {
  background: linear-gradient(135deg, rgba(20, 20, 28, 0.92), rgba(20, 20, 28, 0.55));
  border: 1px solid rgba(255, 255, 255, 0.06);
  border-left: 2px solid rgba(212, 168, 67, 0.6);
  padding: 1.35rem 1.5rem 1.4rem;
  transition: border-color 0.2s, background 0.2s;
}
.page-about__milestone-body:hover {
  border-left-color: var(--color-gold-bright);
  background: linear-gradient(135deg, rgba(35, 35, 47, 0.85), rgba(20, 20, 28, 0.6));
}
.page-about__milestone-title {
  font-size: 1.1rem;
  font-weight: 700;
  letter-spacing: -0.01em;
  margin: 0 0 0.5rem;
}
.page-about__milestone-text {
  font-size: 0.9rem;
  line-height: 1.85;
  color: var(--color-muted-gray);
  margin: 0;
}

/* 数据卡片 */
.page-about__data-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 0.75rem;
  margin: 0 0 2rem;
}
.page-about__data-card {
  background: var(--color-carbon);
  border: 1px solid rgba(255, 255, 255, 0.06);
  border-top: 2px solid rgba(212, 168, 67, 0.5);
  padding: 1.25rem 1.25rem 1.1rem;
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
  transition: background 0.2s, border-color 0.2s, transform 0.2s;
}
.page-about__data-card:hover {
  background: var(--color-graphite);
  border-top-color: var(--color-gold-bright);
  transform: translateY(-2px);
}
.page-about__data-num {
  font-family: var(--font-mono);
  font-size: 2rem;
  font-weight: 700;
  color: var(--color-gold);
  line-height: 1.1;
}
.page-about__data-label {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--color-off-white);
}
.page-about__data-source {
  font-size: 0.75rem;
  color: var(--color-muted-gray);
  line-height: 1.5;
  margin-top: auto;
  border-top: 1px dashed rgba(255, 255, 255, 0.1);
  padding-top: 0.5rem;
}

/* 数据可视化 */
.page-about__data-visual {
  display: grid;
  gap: 1.5rem;
  margin-top: 1rem;
}
.page-about__ring {
  text-align: center;
}
.page-about__ring svg {
  width: 100%;
  max-width: 220px;
  height: auto;
}
.page-about__ring-note {
  font-size: 0.8rem;
  color: var(--color-muted-gray);
  margin-top: 0.75rem;
  line-height: 1.6;
}
.page-about__data-img {
  margin: 0;
}
.page-about__data-img img {
  width: 100%;
  height: auto;
  display: block;
  border: 1px solid rgba(255, 255, 255, 0.07);
}

/* 安全与合规 */
.page-about__security-grid {
  display: grid;
  gap: 1rem;
  margin-bottom: 2rem;
}
.page-about__security-card {
  background: var(--color-carbon);
  border: 1px solid rgba(255, 255, 255, 0.07);
  padding: 1.75rem 1.5rem;
  position: relative;
  overflow: hidden;
  transition: border-color 0.2s, background 0.2s;
}
.page-about__security-card::after {
  content: '';
  position: absolute;
  right: -1.5rem;
  top: -1.5rem;
  width: 4rem;
  height: 4rem;
  border-right: 1px solid rgba(212, 168, 67, 0.3);
  border-top: 1px solid rgba(212, 168, 67, 0.3);
  transform: rotate(45deg);
}
.page-about__security-card:hover {
  border-color: rgba(212, 168, 67, 0.4);
  background: var(--color-graphite);
}
.page-about__security-card h3 {
  font-size: 1rem;
  font-weight: 700;
  margin: 1rem 0 0.5rem;
}
.page-about__security-card p {
  font-size: 0.85rem;
  line-height: 1.7;
  color: var(--color-muted-gray);
  margin: 0;
}
.page-about__shield svg {
  width: 56px;
  height: 68px;
  display: block;
}
.page-about__security-media {
  max-width: 640px;
  margin: 1.5rem auto 0;
}
.page-about__security-media img {
  width: 100%;
  height: auto;
  display: block;
  clip-path: polygon(0 0, calc(100% - 1rem) 0, 100% 1rem, 100% 100%, 1rem 100%, 0 calc(100% - 1rem));
}
.page-about__security-statement {
  margin-top: 1.5rem;
  padding: 1rem 1.25rem;
  border-left: 3px solid var(--color-tech-blue);
  background: rgba(42, 109, 181, 0.06);
  color: var(--color-muted-gray);
  font-size: 0.88rem;
  line-height: 1.8;
}

/* 合作生态 */
.page-about__eco-grid {
  display: grid;
  gap: 1rem;
}
.page-about__eco-card {
  position: relative;
  background: linear-gradient(135deg, rgba(20, 20, 28, 0.95), rgba(35, 35, 47, 0.8));
  border: 1px solid rgba(255, 255, 255, 0.07);
  padding: 1.5rem 1.5rem 1.5rem 2rem;
  overflow: hidden;
  transition: border-color 0.2s, background 0.2s;
}
.page-about__eco-card::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 3px;
  background: var(--color-tech-blue);
  transition: background 0.2s;
}
.page-about__eco-card:hover {
  border-color: rgba(212, 168, 67, 0.35);
  background: linear-gradient(135deg, rgba(35, 35, 47, 0.9), rgba(20, 20, 28, 0.8));
}
.page-about__eco-card:hover::before {
  background: var(--color-gold);
}
.page-about__eco-card h3 {
  font-size: 1.05rem;
  font-weight: 700;
  margin: 0 0 0.5rem;
}
.page-about__eco-card p {
  font-size: 0.88rem;
  color: var(--color-muted-gray);
  line-height: 1.7;
  margin: 0;
}
.page-about__eco-tag {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.67rem;
  letter-spacing: 0.12em;
  color: var(--color-gold);
  border: 1px solid rgba(212, 168, 67, 0.4);
  padding: 0.2rem 0.45rem;
  margin-bottom: 0.75rem;
  text-transform: uppercase;
}

/* CTA */
.page-about__cta {
  margin: 3rem 0 5rem;
  background: linear-gradient(120deg, rgba(212, 168, 67, 0.12), rgba(42, 109, 181, 0.06) 50%, rgba(212, 168, 67, 0.04));
  border: 1px solid rgba(212, 168, 67, 0.3);
  border-left: 4px solid var(--color-gold);
  padding: 2.5rem 1.75rem;
  position: relative;
  overflow: hidden;
}
.page-about__cta::before {
  content: '04';
  position: absolute;
  right: 0.75rem;
  top: -0.35rem;
  font-family: var(--font-mono);
  font-size: 8rem;
  font-weight: 700;
  color: rgba(212, 168, 67, 0.08);
  line-height: 1;
  pointer-events: none;
}
.page-about__cta-inner {
  position: relative;
  z-index: 1;
}
.page-about__cta-title {
  font-size: 1.5rem;
  font-weight: 800;
  margin: 0 0 0.75rem;
}
.page-about__cta-text {
  color: var(--color-muted-gray);
  font-size: 0.95rem;
  line-height: 1.7;
  max-width: 54ch;
  margin-bottom: 1.75rem;
}
.page-about__cta-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
}

/* 平板与桌面 */
@media (min-width: 640px) {
  .page-about__data-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 680px) {
  .page-about__security-grid {
    grid-template-columns: repeat(3, 1fr);
  }
  .page-about__eco-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 760px) {
  .page-about__data-visual {
    grid-template-columns: 240px 1fr;
    align-items: center;
  }
}

@media (min-width: 900px) {
  .page-about__hero-grid {
    grid-template-columns: 1.1fr 0.9fr;
    align-items: center;
    gap: 3rem;
  }
}

@media (min-width: 992px) {
  .page-about__track {
    display: grid;
    grid-template-columns: 220px minmax(0, 1fr);
    gap: 3rem;
    padding-top: 1rem;
  }
  .page-about__anchors {
    flex-direction: column;
    overflow: visible;
    position: sticky;
    top: calc(var(--header-height) + 2rem);
    align-self: start;
    gap: 0.25rem;
    padding: 0;
    margin: 0;
  }
  .page-about__anchors-label {
    display: inline-block;
    font-family: var(--font-mono);
    font-size: 0.7rem;
    letter-spacing: 0.16em;
    text-transform: uppercase;
    color: var(--color-muted-gray);
    border-bottom: 1px solid var(--about-muted-line);
    padding-bottom: 0.75rem;
    margin-bottom: 0.75rem;
  }
  .page-about__anchor {
    background: transparent;
    border: none;
    border-left: 2px solid rgba(255, 255, 255, 0.08);
    padding: 0.65rem 0.5rem 0.65rem 1rem;
    font-size: 0.8rem;
    width: 100%;
    justify-content: flex-start;
  }
  .page-about__anchor:hover,
  .page-about__anchor:focus-visible {
    background: rgba(20, 20, 28, 0.8);
    border-left-color: var(--color-gold);
    color: var(--color-gold-bright);
  }
}

@media (min-width: 1000px) {
  .page-about__data-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}