.page-about {
  --about-line-color: rgba(232, 240, 236, 0.14);
  --about-green-soft: rgba(0, 229, 136, 0.08);
  --about-orange-soft: rgba(255, 77, 0, 0.10);
  background: var(--deep-ink);
  color: var(--powder-white);
}

/* 面包屑 */
.page-about__breadcrumb {
  padding: var(--space-5) 0 var(--space-2);
  font-size: 0.8rem;
  color: var(--fog-gray);
}
.page-about__breadcrumb a {
  color: var(--terminal-green);
  text-decoration: none;
  transition: color 0.2s var(--ease-out);
}
.page-about__breadcrumb a:hover {
  color: var(--powder-white);
}
.page-about__breadcrumb .breadcrumb__sep {
  margin: 0 var(--space-2);
  color: var(--fog-gray);
}

/* 首屏 Hero */
.page-about__hero {
  padding: var(--space-4) 0 var(--space-7);
  border-bottom: 1px solid var(--line-subtle);
}
.page-about__hero-inner {
  display: grid;
  gap: var(--space-6);
  align-items: center;
}
.page-about__hero-copy h1 {
  font-family: var(--font-head);
  font-size: 1.9rem;
  line-height: 1.22;
  margin: var(--space-4) 0 var(--space-5);
  letter-spacing: 0.01em;
}
.page-about__hero-copy h1::after {
  content: "";
  display: block;
  width: 56px;
  height: 4px;
  background: linear-gradient(90deg, var(--terminal-green), var(--pulse-orange));
  margin-top: var(--space-4);
}
.page-about__hero-lead {
  color: var(--fog-gray);
  font-size: 0.95rem;
  line-height: 1.8;
  max-width: 46em;
  margin-bottom: 0;
}
.page-about__hero-stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-3);
  margin-top: var(--space-6);
  border-top: 1px solid var(--line-subtle);
  padding-top: var(--space-5);
}
.page-about__hero-stat {
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
  padding-right: var(--space-3);
  border-right: 1px solid var(--line-subtle);
}
.page-about__hero-stat:last-child {
  border-right: none;
}
.page-about__hero-stat .stat-num {
  font-size: 2rem;
}
.page-about__stat-unit {
  font-family: var(--font-data);
  font-size: 1rem;
  color: var(--terminal-green);
  margin-left: 2px;
}
.page-about__hero-figure {
  margin: 0;
  position: relative;
}
.page-about__brand-mark {
  width: 100%;
  max-width: 480px;
  height: auto;
  aspect-ratio: 1;
  object-fit: cover;
  border: 1px solid var(--line-subtle);
  background: var(--panorama-blue);
  display: block;
  margin: 0 auto;
}
.page-about__hero-caption {
  margin-top: var(--space-3);
  font-size: 0.72rem;
  color: var(--data-cyan);
  text-align: center;
}

/* 页内锚点跳转 */
.page-about__jump {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2) var(--space-4);
  padding: var(--space-4) 0;
  border-bottom: 1px solid var(--line-subtle);
}
.page-about__jump-link {
  font-size: 0.78rem;
  color: var(--fog-gray);
  text-decoration: none;
  padding: var(--space-1) var(--space-2);
  border: 1px solid transparent;
  transition: color 0.2s var(--ease-out), border-color 0.2s var(--ease-out), background 0.2s var(--ease-out);
}
.page-about__jump-link:hover {
  color: var(--terminal-green);
  border-color: var(--line-subtle);
  background: var(--about-green-soft);
}

/* 01 品牌定位 */
.page-about__mission {
  padding: var(--space-7) 0;
  border-bottom: 1px solid var(--line-subtle);
}
.page-about__mission-grid {
  display: grid;
  gap: var(--space-6);
}
.page-about__mission-body p {
  color: var(--fog-gray);
  line-height: 1.85;
  margin: 0 0 var(--space-4);
  font-size: 0.95rem;
}
.page-about__mission-note {
  display: inline-block;
  font-size: 0.82rem;
  color: var(--warning-yellow);
  border-left: 2px solid var(--warning-yellow);
  padding-left: var(--space-3);
  margin-top: var(--space-2);
}

/* 02/03 左右分栏 */
.page-about__core {
  padding: var(--space-7) 0;
  border-bottom: 1px solid var(--line-subtle);
}
.page-about__core-grid {
  display: grid;
  gap: var(--space-8);
}

/* — 时间线列 */
.page-about__timeline-col .section-head {
  margin-bottom: var(--space-5);
}
.page-about__timeline-img {
  width: 100%;
  height: auto;
  max-height: 200px;
  object-fit: cover;
  border: 1px solid var(--line-subtle);
  margin-bottom: var(--space-6);
}
.page-about__timeline {
  position: relative;
}
.page-about__timeline-item {
  position: relative;
  padding: 0 0 var(--space-6) var(--space-6);
  border-left: 1px solid var(--about-line-color);
}
.page-about__timeline-item::before {
  content: "";
  position: absolute;
  left: -4px;
  top: 6px;
  width: 7px;
  height: 7px;
  background: var(--terminal-green);
  border-radius: 0;
}
.page-about__timeline-item--current::before {
  background: var(--pulse-orange);
  box-shadow: 0 0 0 0 rgba(255, 77, 0, 0.45);
  animation: page-about-pulse 2s var(--ease-out) infinite;
}
.page-about__timeline-year {
  display: inline-block;
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--terminal-green);
  margin-bottom: var(--space-2);
  letter-spacing: 0.02em;
}
.page-about__timeline-item--current .page-about__timeline-year {
  color: var(--pulse-orange);
}
.page-about__timeline-body h3 {
  font-size: 1.05rem;
  color: var(--powder-white);
  margin: 0 0 var(--space-2);
  font-weight: 700;
}
.page-about__timeline-body p {
  font-size: 0.86rem;
  color: var(--fog-gray);
  line-height: 1.7;
  margin: 0;
}

/* — 覆盖网络列 */
.page-about__coverage-col .section-head {
  margin-bottom: var(--space-5);
}
.page-about__coverage-list {
  margin-bottom: var(--space-6);
}
.page-about__coverage-region {
  border: 1px solid var(--line-subtle);
  border-radius: 0;
  margin-bottom: var(--space-3);
  background: var(--panorama-blue);
  transition: border-color 0.25s var(--ease-out);
}
.page-about__coverage-region[open] {
  border-color: var(--terminal-green);
}
.page-about__coverage-region summary {
  display: flex;
  align-items: center;
  gap: var(--space-4);
  padding: var(--space-4);
  cursor: pointer;
  list-style: none;
  user-select: none;
}
.page-about__coverage-region summary::-webkit-details-marker {
  display: none;
}
.page-about__coverage-region summary::-webkit-details-marker {
  display: none;
}
.page-about__coverage-num {
  font-family: var(--font-data);
  font-size: 1.6rem;
  font-weight: 700;
  color: var(--terminal-green);
  min-width: 3ch;
  line-height: 1;
}
.page-about__coverage-region:nth-child(2) .page-about__coverage-num {
  color: var(--data-cyan);
}
.page-about__coverage-region:nth-child(3) .page-about__coverage-num {
  color: var(--pulse-orange);
}
.page-about__coverage-name {
  flex: 1;
  font-size: 0.98rem;
  font-weight: 700;
  color: var(--powder-white);
}
.page-about__coverage-toggle {
  font-family: var(--font-data);
  color: var(--fog-gray);
  font-size: 1.2rem;
  line-height: 1;
  transition: transform 0.25s var(--ease-out), color 0.25s var(--ease-out);
}
.page-about__coverage-region[open] .page-about__coverage-toggle {
  color: var(--terminal-green);
  transform: rotate(45deg);
}
.page-about__coverage-detail {
  padding: 0 var(--space-4) var(--space-4);
  color: var(--fog-gray);
  font-size: 0.85rem;
  line-height: 1.7;
  border-top: 1px solid var(--line-subtle);
  padding-top: var(--space-3);
  margin-left: var(--space-4);
  margin-right: var(--space-4);
}
.page-about__coverage-detail p {
  margin: 0;
}
.page-about__coverage-region[open] .page-about__coverage-detail {
  animation: page-about-fade 0.28s var(--ease-out);
}
.page-about__coverage-figure {
  margin: 0;
}
.page-about__coverage-img {
  width: 100%;
  height: auto;
  border: 1px solid var(--line-subtle);
  background: var(--panorama-blue);
}
.page-about__coverage-caption {
  margin-top: var(--space-3);
  font-size: 0.72rem;
  color: var(--data-cyan);
}

/* 04 质量保障 */
.page-about__quality {
  padding: var(--space-7) 0;
  border-bottom: 1px solid var(--line-subtle);
}
.page-about__quality-flow {
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  gap: var(--space-4);
}
.page-about__quality-step {
  position: relative;
  border: 1px solid var(--line-subtle);
  border-top: 3px solid var(--terminal-green);
  border-radius: 0;
  padding: var(--space-5);
  background: linear-gradient(135deg, rgba(15, 35, 64, 0.75), rgba(8, 18, 30, 0.35));
}
.page-about__quality-step:nth-child(2) {
  border-top-color: var(--data-cyan);
}
.page-about__quality-step:nth-child(3) {
  border-top-color: var(--warning-yellow);
}
.page-about__quality-step:nth-child(4) {
  border-top-color: var(--pulse-orange);
}
.page-about__quality-num {
  display: block;
  font-size: 0.82rem;
  color: var(--terminal-green);
  margin-bottom: var(--space-3);
  letter-spacing: 0.08em;
}
.page-about__quality-step:nth-child(2) .page-about__quality-num {
  color: var(--data-cyan);
}
.page-about__quality-step:nth-child(3) .page-about__quality-num {
  color: var(--warning-yellow);
}
.page-about__quality-step:nth-child(4) .page-about__quality-num {
  color: var(--pulse-orange);
}
.page-about__quality-step h3 {
  font-size: 1.08rem;
  color: var(--powder-white);
  margin: 0 0 var(--space-2);
  font-weight: 700;
}
.page-about__quality-step p {
  font-size: 0.84rem;
  color: var(--fog-gray);
  line-height: 1.7;
  margin: 0;
}

/* 05 团队与组织 */
.page-about__team {
  padding: var(--space-7) 0;
  border-bottom: 1px solid var(--line-subtle);
}
.page-about__team-grid {
  display: grid;
  gap: var(--space-4);
}
.page-about__team-card {
  padding: var(--space-5);
  border-radius: 0;
}
.page-about__team-card h3 {
  font-size: 1.2rem;
  color: var(--powder-white);
  margin: var(--space-3) 0 var(--space-2);
  font-weight: 700;
}
.page-about__team-card p:not(.kicker) {
  font-size: 0.86rem;
  color: var(--fog-gray);
  line-height: 1.7;
  margin: 0;
}

/* 探索区 */
.page-about__explore {
  padding: var(--space-7) 0 var(--space-9);
}
.page-about__explore-grid {
  display: grid;
  gap: var(--space-3);
}
.page-about__explore-link {
  display: flex;
  align-items: center;
  gap: var(--space-4);
  padding: var(--space-4) var(--space-5);
  border: 1px solid var(--line-subtle);
  border-radius: 0;
  text-decoration: none;
  color: var(--powder-white);
  background: rgba(8, 18, 30, 0.6);
  transition: border-color 0.25s var(--ease-out), background 0.25s var(--ease-out), transform 0.25s var(--ease-out);
}
.page-about__explore-index {
  color: var(--data-cyan);
  font-size: 0.85rem;
}
.page-about__explore-label {
  flex: 1;
  font-size: 1rem;
  font-weight: 700;
}
.page-about__explore-arrow {
  color: var(--terminal-green);
  font-size: 1.25rem;
  transition: transform 0.25s var(--ease-out);
}
.page-about__explore-link:hover {
  border-color: var(--terminal-green);
  background: var(--about-green-soft);
}
.page-about__explore-link:hover .page-about__explore-arrow {
  transform: translateX(4px);
}

/* 关键帧 */
@keyframes page-about-pulse {
  0%, 100% {
    box-shadow: 0 0 0 0 rgba(255, 77, 0, 0.45);
  }
  50% {
    box-shadow: 0 0 0 6px rgba(255, 77, 0, 0);
  }
}
@keyframes page-about-fade {
  from {
    opacity: 0;
    transform: translateY(-4px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* 平板及以上 */
@media (min-width: 768px) {
  .page-about__hero {
    padding: var(--space-6) 0 var(--space-8);
  }
  .page-about__hero-inner {
    grid-template-columns: 7fr 5fr;
    gap: var(--space-8);
  }
  .page-about__hero-copy h1 {
    font-size: 2.6rem;
  }
  .page-about__hero-lead {
    font-size: 1.02rem;
  }
  .page-about__hero-stats {
    gap: var(--space-5);
    padding-top: var(--space-6);
  }
  .page-about__hero-stat .stat-num {
    font-size: 2.3rem;
  }
  .page-about__brand-mark {
    max-width: 100%;
  }
  .page-about__jump {
    gap: var(--space-3) var(--space-6);
    padding: var(--space-5) 0;
  }

  .page-about__mission-grid {
    grid-template-columns: 5fr 7fr;
    gap: var(--space-8);
  }

  .page-about__core-grid {
    grid-template-columns: 5fr 7fr;
    gap: var(--space-7);
    position: relative;
  }
  .page-about__core-grid::before {
    content: "";
    position: absolute;
    left: 50%;
    top: 0;
    bottom: 0;
    width: 1px;
    background: var(--line-subtle);
    transform: translateX(-50%);
  }
  .page-about__timeline-col {
    padding-right: var(--space-6);
  }
  .page-about__coverage-col {
    padding-left: var(--space-6);
  }
  .page-about__timeline-img {
    max-height: 180px;
  }

  .page-about__quality-flow {
    grid-template-columns: repeat(4, 1fr);
    gap: 0;
    border: 1px solid var(--line-subtle);
    background: rgba(8, 18, 30, 0.4);
  }
  .page-about__quality-step {
    border: none;
    border-right: 1px solid var(--line-subtle);
    border-radius: 0;
    background: none;
  }
  .page-about__quality-step:last-child {
    border-right: none;
  }

  .page-about__team-grid {
    grid-template-columns: repeat(3, 1fr);
  }
  .page-about__explore-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

/* 桌面宽 */
@media (min-width: 1024px) {
  .page-about__hero-copy h1 {
    font-size: 3rem;
  }
  .page-about__hero-lead {
    font-size: 1.1rem;
    line-height: 1.9;
  }
  .page-about__timeline-img {
    max-height: 220px;
  }
  .page-about__coverage-num {
    font-size: 1.9rem;
  }
}

/* 减弱动效 */
@media (prefers-reduced-motion: reduce) {
  .page-about__timeline-item--current::before,
  .page-about__coverage-region[open] .page-about__coverage-detail {
    animation: none;
  }
  .page-about__explore-arrow {
    transition: none;
  }
}