.page-about {
  --about-gap: clamp(1.5rem, 4vw, 3.5rem);
  background: var(--bg-night);
  color: var(--white);
  overflow-x: hidden;
}

/* ===== 首屏 ===== */
.about-hero {
  position: relative;
  padding-top: var(--space-lg);
  background: var(--bg-night);
  border-bottom: 1px solid var(--bg-glass);
}
.about-hero-bg {
  position: absolute;
  top: 0;
  right: 0;
  bottom: 0;
  left: 0;
  overflow: hidden;
  z-index: 0;
}
.about-hero-bg img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: 0.28;
  filter: saturate(0.7) contrast(1.15);
}
.about-hero-shade {
  position: absolute;
  top: 0;
  right: 0;
  bottom: 0;
  left: 0;
  z-index: 0;
  background:
    linear-gradient(180deg, rgba(10,14,23,0.72) 0%, rgba(10,14,23,0.22) 46%, rgba(10,14,23,0.94) 100%),
    radial-gradient(70% 50% at 18% 22%, rgba(247,181,0,0.12), transparent 60%);
}
.about-hero-inner {
  position: relative;
  z-index: 1;
  padding-top: var(--space-xl);
  padding-bottom: var(--space-xl);
  display: flex;
  flex-direction: column;
  align-items: flex-start;
}
.about-hero .breadcrumb {
  margin-bottom: var(--space-md);
}
.about-eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 0.625rem;
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  color: var(--line-green);
  letter-spacing: 0.16em;
  margin-bottom: var(--space-sm);
}
.about-eyebrow::before {
  content: "";
  width: 2.5rem;
  height: 2px;
  background: var(--line-green);
  flex: 0 0 auto;
}
.about-hero h1 {
  font-family: var(--font-display);
  font-size: clamp(2.3rem, 6.6vw, 4.6rem);
  line-height: 1.05;
  letter-spacing: -0.02em;
  max-width: 11em;
  margin: 0 0 var(--space-md) 0;
  text-shadow: 0 0 30px rgba(0, 216, 255, 0.18);
}
.about-hero h1::after {
  content: "";
  display: block;
  width: 4.5rem;
  height: 0.375rem;
  background: linear-gradient(90deg, var(--gold), var(--line-blue));
  margin-top: var(--space-md);
  margin-left: 0.5rem;
}
.about-hero-lead {
  font-size: clamp(1rem, 1.6vw, 1.3rem);
  line-height: 1.8;
  color: var(--muted);
  max-width: 62ch;
  margin-bottom: 0;
}
.about-hero-lead strong {
  color: var(--white);
  font-weight: 600;
}
.about-hero .btn-group {
  flex-wrap: wrap;
  margin-top: var(--space-md);
}
.about-ticker {
  position: relative;
  z-index: 1;
  border-top: 1px solid var(--bg-glass);
  background: rgba(10, 14, 23, 0.8);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
}
.about-ticker-list {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-md) var(--space-lg);
  padding-top: var(--space-sm);
  padding-bottom: var(--space-sm);
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  color: var(--muted);
}
.about-ticker-list span::before {
  content: "●";
  color: var(--line-blue);
  margin-right: 0.5rem;
  font-size: 0.5rem;
  vertical-align: middle;
}

/* ===== 通用章节头 ===== */
.about-blockhead {
  margin-bottom: var(--space-lg);
  position: relative;
}
.about-blockhead .section-index {
  font-family: var(--font-mono);
  font-size: 0.875rem;
  letter-spacing: 0.14em;
  color: var(--gold);
  display: block;
  margin-bottom: var(--space-sm);
}
.about-blockhead .section-index::after {
  content: "";
  display: inline-block;
  width: 2.5rem;
  height: 1px;
  background: var(--gold);
  margin-left: 0.625rem;
  vertical-align: middle;
}
.about-blockhead h2 {
  font-family: var(--font-display);
  font-size: clamp(1.9rem, 4vw, 2.8rem);
  line-height: 1.16;
  margin: 0 0 var(--space-sm);
  letter-spacing: -0.01em;
}
.about-blockhead .section-desc {
  margin: 0;
  color: var(--muted);
}
.about-blockhead-split {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: var(--space-md);
  margin-bottom: var(--space-lg);
}
.about-field-badge {
  display: none;
  flex: 0 0 auto;
  width: 5.5rem;
  height: 5.5rem;
  place-items: center;
  border: 1px solid var(--bg-glass);
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.03);
  color: rgba(255, 255, 255, 0.45);
}
.about-field-badge svg {
  width: 3.75rem;
  height: 4.25rem;
}

/* ===== 品牌档案 ===== */
.about-profile {
  padding: var(--space-xl) 0;
  background: linear-gradient(180deg, var(--bg-night), var(--bg-carbon));
}
.about-profile-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--about-gap);
}
.about-profile-copy p {
  font-size: 1rem;
  line-height: 1.8;
  color: var(--muted);
  margin-bottom: var(--space-md);
}
.about-profile-copy p a {
  color: var(--line-blue);
  text-decoration: underline;
  text-underline-offset: 0.15em;
}
.about-profile-copy p a:hover {
  color: var(--white);
}
.about-profile-aside {
  display: grid;
  gap: var(--space-md);
  align-content: start;
}
.about-id-card {
  padding: var(--space-md);
  border: 1px solid var(--bg-glass);
  background: rgba(255, 255, 255, 0.03);
  border-radius: var(--radius-md);
}
.about-id-label {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--line-blue);
  letter-spacing: 0.14em;
  display: block;
  margin-bottom: var(--space-sm);
}
.about-id-title {
  font-family: var(--font-display);
  font-size: 1.25rem;
  line-height: 1.4;
  display: block;
  margin-bottom: var(--space-md);
}
.about-id-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: var(--space-sm);
}
.about-id-list li {
  position: relative;
  padding-left: 1.25rem;
  font-size: 0.875rem;
  line-height: 1.7;
  color: var(--muted);
}
.about-id-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.6rem;
  width: 0.5rem;
  height: 0.5rem;
  background: var(--line-blue);
  clip-path: polygon(0 0, 100% 50%, 0 100%);
}
.about-index-card {
  background: rgba(255, 255, 255, 0.02);
  border-left: 3px solid var(--gold);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  padding: var(--space-md);
}
.about-index-card h3 {
  font-size: 0.9375rem;
  margin: 0 0 var(--space-sm);
}
.about-index-card ol {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: var(--space-sm);
}
.about-index-card a {
  color: var(--muted);
  font-size: 0.875rem;
  text-decoration: none;
  transition: color var(--t-fast) ease;
}
.about-index-card a:hover {
  color: var(--white);
}

/* ===== 数字里程碑 ===== */
.about-stats {
  position: relative;
  padding: var(--space-xl) 0;
  background:
    radial-gradient(700px circle at 82% 18%, rgba(0, 216, 255, 0.08), transparent 60%),
    linear-gradient(160deg, var(--bg-carbon), var(--bg-night));
}
.about-stats::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, rgba(0, 255, 163, 0.5), transparent);
}
.about-stats-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-md);
}
.about-stat-item {
  position: relative;
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid var(--bg-glass);
  border-radius: var(--radius-md);
  padding: var(--space-md);
  overflow: hidden;
  transition: transform var(--t-fast) ease, border-color var(--t-fast) ease, box-shadow var(--t-fast) ease;
}
.about-stat-item::after {
  content: "";
  position: absolute;
  right: 0;
  bottom: 0;
  width: 2.5rem;
  height: 2.5rem;
  border-right: 2px solid var(--line-blue);
  border-bottom: 2px solid var(--line-blue);
  opacity: 0.6;
  border-radius: 0 0 var(--radius-md) 0;
}
.about-stat-item:hover {
  transform: translateY(-2px);
  border-color: rgba(0, 216, 255, 0.4);
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.35), 0 0 20px rgba(0, 216, 255, 0.06);
}
.about-stat-gold {
  background: linear-gradient(135deg, rgba(247, 181, 0, 0.12), rgba(255, 215, 94, 0.04));
  border-color: rgba(247, 181, 0, 0.35);
}
.about-stat-num {
  font-family: var(--font-display);
  font-size: clamp(2rem, 5vw, 3.25rem);
  color: var(--gold-light);
  display: block;
  line-height: 1.1;
  margin-bottom: var(--space-sm);
}
.about-stat-unit {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  display: block;
  margin-bottom: var(--space-sm);
}
.about-stat-desc {
  font-size: 0.875rem;
  line-height: 1.7;
  color: var(--muted);
  margin: 0;
}

/* ===== 发展历程 ===== */
.about-timeline {
  position: relative;
  padding: var(--space-xl) 0;
  background: var(--bg-night);
}
.about-timeline::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: linear-gradient(90deg, var(--gold), var(--line-blue), var(--line-green));
  opacity: 0.7;
}
.about-timeline-layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--about-gap);
}
.about-timeline-steps {
  display: grid;
  gap: 0;
}
.about-tl-step {
  display: grid;
  grid-template-columns: 1.5rem 1fr;
  gap: var(--space-md);
  padding-bottom: var(--space-lg);
}
.about-tl-step:last-child {
  padding-bottom: 0;
}
.about-tl-mark {
  position: relative;
  height: 100%;
}
.about-tl-mark::before {
  content: "";
  position: absolute;
  left: 50%;
  top: 0.5rem;
  bottom: 0;
  width: 2px;
  transform: translateX(-50%);
  background: linear-gradient(180deg, var(--gold), var(--line-blue), var(--line-green));
  opacity: 0.55;
}
.about-tl-step:last-child .about-tl-mark::before {
  display: none;
}
.about-tl-mark::after {
  content: "";
  position: absolute;
  left: 50%;
  top: 0;
  width: 0.75rem;
  height: 0.75rem;
  transform: translateX(-50%);
  background: var(--bg-night);
  border: 2px solid var(--gold);
  border-radius: 50%;
  box-shadow: 0 0 14px rgba(247, 181, 0, 0.4);
}
.about-tl-season {
  font-family: var(--font-mono);
  color: var(--gold);
  font-size: 0.8125rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  display: block;
  margin-bottom: var(--space-sm);
}
.about-tl-content h3 {
  font-size: 1.25rem;
  margin-bottom: var(--space-sm);
}
.about-tl-content p {
  font-size: 0.9375rem;
  line-height: 1.7;
  color: var(--muted);
  margin: 0;
}
.about-timeline-aside {
  display: grid;
  gap: var(--space-md);
  align-content: start;
}
.about-timeline-figure {
  margin: 0;
  background: var(--bg-carbon);
  border-radius: var(--radius-md);
  padding: var(--space-sm);
  border: 1px solid var(--bg-glass);
}
.about-timeline-figure img {
  width: 100%;
  height: auto;
  border-radius: var(--radius-sm);
  display: block;
}
.about-timeline-figure figcaption,
.about-lhasa-media figcaption {
  margin-top: var(--space-sm);
  color: var(--muted);
  font-size: 0.8125rem;
  line-height: 1.6;
}

/* ===== 版本对比 ===== */
.about-versions {
  margin-top: var(--space-lg);
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-md);
  position: relative;
  background: var(--bg-carbon);
  border-radius: var(--radius-lg);
  padding: var(--space-md);
  border: 1px solid var(--bg-glass);
}
.about-version-card {
  padding: var(--space-md);
  border-radius: var(--radius-md);
  background: rgba(255, 255, 255, 0.03);
}
.about-version-old {
  border: 1px dashed var(--muted);
  opacity: 0.75;
}
.about-version-new {
  border: 1px solid rgba(0, 216, 255, 0.35);
  background: linear-gradient(135deg, rgba(0, 216, 255, 0.08), rgba(0, 255, 163, 0.03));
}
.about-version-label {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.12em;
  color: var(--muted);
  display: block;
  margin-bottom: var(--space-sm);
}
.about-version-new .about-version-label {
  color: var(--line-blue);
}
.about-version-card strong {
  font-size: 1.125rem;
  display: block;
  margin-bottom: var(--space-sm);
}
.about-version-card p {
  margin: 0;
  font-size: 0.875rem;
  line-height: 1.7;
  color: var(--muted);
}
.about-version-arrow {
  font-size: 1.75rem;
  color: var(--gold);
  line-height: 1;
  text-align: center;
  transform: rotate(90deg);
  user-select: none;
}

/* ===== 技术底座 ===== */
.about-tech {
  padding: var(--space-xl) 0;
  background:
    repeating-linear-gradient(45deg, transparent, transparent 12px, rgba(255, 255, 255, 0.015) 12px, rgba(255, 255, 255, 0.015) 24px),
    var(--bg-carbon);
}
.about-tech-layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-md);
}
.about-tech-major {
  background:
    radial-gradient(80% 120% at 0% 0%, rgba(0, 255, 163, 0.1), transparent 60%),
    rgba(255, 255, 255, 0.03);
  padding: var(--space-lg);
  border-radius: var(--radius-lg);
  border: 1px solid rgba(0, 255, 163, 0.3);
}
.about-tech-tag {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.14em;
  color: var(--line-green);
  border: 1px solid rgba(0, 255, 163, 0.4);
  background: rgba(0, 255, 163, 0.06);
  padding: 0.25rem 0.625rem;
  border-radius: 999px;
  margin-bottom: var(--space-md);
}
.about-tech-major h3 {
  font-family: var(--font-display);
  font-size: clamp(1.5rem, 3vw, 2.25rem);
  margin-bottom: var(--space-sm);
  line-height: 1.2;
}
.about-tech-major p {
  color: var(--muted);
  font-size: 0.9375rem;
  line-height: 1.7;
  margin-bottom: var(--space-md);
}
.about-tech-meta {
  border-top: 1px solid var(--bg-glass);
  padding-top: var(--space-md);
  display: grid;
  gap: var(--space-sm);
}
.about-tech-meta .data-row {
  display: flex;
  justify-content: space-between;
  gap: var(--space-md);
  font-size: 0.875rem;
}
.about-tech-meta .data-label {
  color: var(--muted);
}
.about-tech-meta .data-value {
  color: var(--white);
  font-family: var(--font-mono);
}
.about-tech-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-md);
}
.about-tech-mini {
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid var(--bg-glass);
  padding: var(--space-md);
  border-radius: var(--radius-md);
  transition: border-color var(--t-fast) ease, transform var(--t-fast) ease;
}
.about-tech-mini:hover {
  border-color: rgba(0, 216, 255, 0.4);
  transform: translateY(-2px);
}
.about-tech-mini h3 {
  font-size: 1rem;
  color: var(--line-blue);
  margin-bottom: var(--space-sm);
}
.about-tech-mini p {
  font-size: 0.875rem;
  color: var(--muted);
  line-height: 1.7;
  margin: 0;
}

/* ===== 西藏在地实践 ===== */
.about-lhasa {
  position: relative;
  padding: var(--space-xl) 0;
  background:
    radial-gradient(120% 90% at 85% 10%, rgba(0, 216, 255, 0.07), transparent 60%),
    radial-gradient(80% 70% at 10% 80%, rgba(247, 181, 0, 0.06), transparent 55%),
    var(--bg-night);
  border-top: 1px solid var(--bg-glass);
}
.about-lhasa-layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--about-gap);
  align-items: center;
}
.about-lhasa-copy p {
  color: var(--muted);
  line-height: 1.8;
  margin-bottom: var(--space-md);
}
.about-lhasa-tags {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-sm);
  margin-top: var(--space-md);
}
.about-lhasa-media {
  margin: 0;
  background: var(--bg-carbon);
  border-radius: var(--radius-md);
  padding: var(--space-sm);
  border: 1px solid var(--bg-glass);
}
.about-lhasa-media img {
  width: 100%;
  height: auto;
  border-radius: var(--radius-sm);
  display: block;
}

/* ===== 结尾转化 ===== */
.about-outro {
  padding: var(--space-xl) 0;
  background: var(--bg-night);
  border-top: 1px solid var(--bg-glass);
}
.about-outro-inner {
  max-width: 820px;
}
.about-outro-label {
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  color: var(--line-green);
  letter-spacing: 0.16em;
  margin-bottom: var(--space-sm);
}
.about-outro h2 {
  font-family: var(--font-display);
  font-size: clamp(1.75rem, 4vw, 2.75rem);
  line-height: 1.2;
  margin: 0 0 var(--space-md);
}
.about-outro p {
  color: var(--muted);
  line-height: 1.8;
  margin-bottom: var(--space-md);
}
.about-outro .btn-group {
  flex-wrap: wrap;
}

/* ===== 响应式布局 ===== */
@media (min-width: 640px) {
  .about-field-badge {
    display: grid;
  }
}

@media (min-width: 760px) {
  .about-versions {
    grid-template-columns: 1fr auto 1fr;
    align-items: stretch;
  }
  .about-version-arrow {
    transform: none;
    display: flex;
    align-items: center;
    justify-content: center;
  }
}

@media (min-width: 800px) {
  .about-profile-grid {
    grid-template-columns: 1.4fr 0.8fr;
    align-items: start;
  }
  .about-stats-grid {
    grid-template-columns: repeat(3, 1fr);
    gap: var(--space-md);
  }
  .about-timeline-layout {
    grid-template-columns: 1.1fr 0.9fr;
    align-items: start;
  }
  .about-tech-layout {
    grid-template-columns: 1.05fr 0.95fr;
    align-items: start;
  }
  .about-tech-grid {
    grid-template-columns: 1fr 1fr;
  }
  .about-lhasa-layout {
    grid-template-columns: 1fr 1fr;
  }
}

@media (min-width: 1200px) {
  .about-profile-grid {
    grid-template-columns: 1.5fr 0.7fr;
  }
  .about-timeline-layout {
    grid-template-columns: 1.2fr 0.8fr;
  }
}