.page-about {
  --about-gridline: rgba(20, 24, 29, 0.05);
  --about-card-bg: #ffffff;
  --about-text-main: #2b3440;
  position: relative;
  background-image:
    linear-gradient(var(--about-gridline) 1px, transparent 1px),
    linear-gradient(90deg, var(--about-gridline) 1px, transparent 1px);
  background-size: 36px 36px;
}

.page-about .breadcrumb {
  margin-bottom: var(--sp-md);
}

.page-about .section-heading {
  margin-bottom: var(--sp-md);
}

.page-about .section-heading h2 {
  margin: var(--sp-sm) 0 0;
  font-family: var(--font-heading);
  font-size: var(--fs-h2);
  font-weight: 900;
  line-height: 1.2;
  letter-spacing: -0.02em;
  color: var(--ink-black);
}

/* 档案导语 */
.archive-hero {
  position: relative;
  padding: var(--sp-lg) 0 var(--sp-2xl);
  border-bottom: var(--border-w) solid var(--ink-black);
}

.archive-hero::after {
  content: "拉萨 · 2018 ——";
  position: absolute;
  right: 0;
  bottom: -12px;
  z-index: 2;
  padding: 3px 10px;
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 0.08em;
  color: var(--brand-blue);
  background: var(--snow-white);
  border: 1px solid var(--ink-black);
  transform: rotate(-2deg);
}

.archive-hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--sp-xl);
  align-items: center;
  margin-top: var(--sp-lg);
}

.archive-hero-copy h1 {
  margin: var(--sp-md) 0;
  font-family: var(--font-heading);
  font-size: var(--fs-h1);
  font-weight: 900;
  line-height: 1.16;
  letter-spacing: -0.03em;
  color: var(--ink-black);
}

.archive-hero-lead {
  max-width: 640px;
  margin: 0;
  padding-left: var(--sp-md);
  border-left: 4px solid var(--brand-blue);
  font-size: var(--fs-body);
  line-height: 1.75;
  color: #3d4852;
}

.archive-hero-lead strong {
  color: var(--ink-black);
  font-weight: 700;
}

.archive-hero-meta {
  display: flex;
  flex-wrap: wrap;
  gap: var(--sp-sm);
  margin-top: var(--sp-lg);
}

.hero-meta-item {
  padding: 4px 10px;
  font-size: var(--fs-label);
  font-weight: 600;
  color: var(--ink-black);
  background: var(--about-card-bg);
  border: 1px dashed var(--ink-black);
  letter-spacing: 0.02em;
}

.archive-hero-stamp {
  display: none;
}

/* 品牌基因 */
.brand-gene {
  padding: var(--sp-2xl) 0;
}

.gene-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--sp-xl);
  margin-top: var(--sp-lg);
}

.gene-paragraph {
  display: grid;
  gap: var(--sp-md);
}

.gene-copy p {
  margin: 0;
  font-size: var(--fs-body);
  line-height: 1.75;
  color: var(--about-text-main);
}

.gene-trait-list {
  list-style: none;
  margin: var(--sp-lg) 0;
  padding: 0;
}

.gene-trait-list li {
  display: flex;
  align-items: flex-start;
  gap: var(--sp-sm);
  padding: 12px 0;
  font-size: var(--fs-body);
  color: var(--about-text-main);
  border-bottom: 1px solid var(--about-gridline);
}

.gene-trait-list li:first-child {
  border-top: 1px solid var(--about-gridline);
}

.trait-mark {
  position: relative;
  top: 6px;
  flex: 0 0 8px;
  width: 8px;
  height: 8px;
  background: var(--brand-blue);
  transform: rotate(45deg);
}

.gene-quote {
  margin: var(--sp-lg) 0 0;
  padding-left: var(--sp-lg);
  border-left: 4px solid var(--ink-black);
}

.gene-quote p {
  margin: 0;
  font-family: var(--font-heading);
  font-size: var(--fs-h4);
  font-weight: 900;
  line-height: 1.45;
  color: var(--ink-black);
}

.gene-figure {
  margin: 0;
}

.gene-figure-frame {
  position: relative;
  background: var(--about-card-bg);
  border: var(--border-w) solid var(--ink-black);
  box-shadow: 6px 6px 0 var(--brand-blue);
}

.gene-figure-frame::before {
  content: "";
  position: absolute;
  top: 10px;
  right: 10px;
  z-index: 1;
  width: 36px;
  height: 36px;
  border-top: 2px solid var(--brand-blue);
  border-right: 2px solid var(--brand-blue);
}

.gene-figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 1000 / 700;
  object-fit: cover;
}

.gene-figure figcaption {
  padding: 8px 12px;
  font-size: var(--fs-small);
  line-height: 1.6;
  color: var(--slate-gray);
  background: var(--about-card-bg);
  border-top: var(--border-w) solid var(--ink-black);
}

/* 斜切分隔 */
.about-angle {
  position: relative;
  z-index: 1;
  display: block;
  height: 14px;
  background: var(--brand-blue);
  clip-path: polygon(0 0, 100% 0, 100% 100%, 8% 100%);
}

.about-angle--paper {
  background: var(--snow-white);
  border-top: var(--border-w) solid var(--ink-black);
  border-bottom: var(--border-w) solid var(--ink-black);
  clip-path: polygon(0 0, 100% 0, 100% 100%, 0 100%);
}

/* 发展里程碑 */
.milestone-section {
  padding: var(--sp-2xl) 0;
  background: var(--ink-black);
  color: var(--snow-white);
}

.milestone-section .section-heading h2 {
  color: var(--snow-white);
}

.timeline-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--sp-lg);
  margin-top: var(--sp-xl);
}

.timeline-index {
  display: flex;
  gap: var(--sp-sm);
  padding: var(--sp-md);
  overflow-x: auto;
  scrollbar-width: none;
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid rgba(255, 255, 255, 0.18);
}

.timeline-index::-webkit-scrollbar {
  display: none;
}

.timeline-index h3 {
  display: none;
}

.timeline-index-link {
  flex: 0 0 auto;
  padding: 6px 12px;
  font-size: var(--fs-small);
  font-weight: 700;
  color: rgba(255, 255, 255, 0.72);
  text-decoration: none;
  border: 1px solid transparent;
  transition: background var(--t-fast), color var(--t-fast), border-color var(--t-fast);
}

.timeline-index-link::before {
  content: "#";
  margin-right: 2px;
  color: var(--brand-blue);
}

.timeline-index-link:hover,
.timeline-index-link.is-active {
  background: var(--brand-blue);
  border-color: var(--brand-blue);
  color: #fff;
}

.timeline-index-link:hover::before,
.timeline-index-link.is-active::before {
  color: #fff;
}

.timeline-track {
  position: relative;
  padding-left: 24px;
}

.timeline-track::before {
  content: "";
  position: absolute;
  left: 7px;
  top: 8px;
  bottom: 8px;
  width: 2px;
  background: linear-gradient(to bottom, var(--brand-blue) 0%, rgba(255, 255, 255, 0.3) 45%, rgba(255, 255, 255, 0.05) 100%);
}

.timeline-item {
  position: relative;
  margin-bottom: var(--sp-xl);
}

.timeline-item:last-child {
  margin-bottom: 0;
}

.timeline-marker {
  position: absolute;
  top: 10px;
  left: -29px;
  width: 18px;
  height: 18px;
  background: var(--snow-white);
  border: 3px solid var(--brand-blue);
  box-shadow: 0 0 0 2px var(--ink-black);
  transform: rotate(45deg);
}

.timeline-item.is-current .timeline-marker {
  background: var(--brand-blue);
  box-shadow: 0 0 0 2px var(--snow-white);
}

.timeline-year {
  margin-bottom: var(--sp-xs);
  font-size: var(--fs-label);
  font-weight: 900;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--brand-blue);
}

.timeline-card {
  padding: var(--sp-lg);
  background: var(--snow-white);
  color: var(--ink-black);
  border: 2px solid var(--ink-black);
  box-shadow: 5px 5px 0 rgba(255, 255, 255, 0.14);
  transition: transform var(--t-fast), box-shadow var(--t-fast);
}

.timeline-card:hover {
  transform: translate(-2px, -2px);
  box-shadow: 6px 6px 0 var(--brand-blue);
}

.timeline-card h3 {
  margin: 0 0 var(--sp-xs);
  font-size: var(--fs-h4);
  font-weight: 900;
  line-height: 1.3;
  color: var(--ink-black);
}

.timeline-card p {
  margin: 0 0 var(--sp-sm);
  font-size: var(--fs-body);
  line-height: 1.75;
  color: var(--about-text-main);
}

.timeline-card .tag {
  margin-top: var(--sp-xs);
}

/* 平台数据 */
.data-section {
  padding: var(--sp-2xl) 0;
  background: var(--snow-white);
}

.data-visual {
  margin: var(--sp-lg) 0 var(--sp-xl);
  background: var(--about-card-bg);
  border: 2px solid var(--ink-black);
  box-shadow: 6px 6px 0 var(--brand-blue);
}

.data-visual img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 1200 / 500;
  object-fit: cover;
}

.data-visual figcaption {
  padding: 8px 12px;
  font-size: var(--fs-small);
  color: var(--slate-gray);
  border-top: 2px solid var(--ink-black);
}

.data-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--sp-md);
  margin-top: var(--sp-lg);
}

.data-card {
  display: flex;
  flex-direction: column;
  padding: var(--sp-lg);
  background: var(--about-card-bg);
  border: 2px solid var(--ink-black);
  border-top: 6px solid var(--brand-blue);
  box-shadow: 4px 4px 0 var(--ink-black);
  transition: transform var(--t-fast), box-shadow var(--t-fast), border-color var(--t-fast);
}

.data-card--green {
  border-top-color: var(--grass-green);
}

.data-card--gold {
  border-top-color: var(--gold-amber);
}

.data-card--red {
  border-top-color: var(--blood-red);
}

.data-card:hover,
.data-card:focus-within {
  transform: translate(-2px, -2px);
  border-color: var(--brand-blue);
  box-shadow: 6px 6px 0 var(--brand-blue);
}

.data-card-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: var(--sp-md);
}

.data-card-label {
  font-size: var(--fs-label);
  font-weight: 700;
  letter-spacing: 0.06em;
  color: var(--slate-gray);
  text-transform: uppercase;
}

.data-card-main {
  display: flex;
  align-items: baseline;
  gap: var(--sp-xs);
  margin-bottom: var(--sp-sm);
}

.data-card-main .stat-number {
  display: block;
  font-family: var(--font-heading);
  font-size: clamp(36px, 5vw, 56px);
  font-weight: 900;
  line-height: 1;
  letter-spacing: -0.03em;
}

.data-unit {
  font-size: var(--fs-small);
  font-weight: 700;
  color: var(--slate-gray);
}

.data-desc {
  flex: 1;
  margin: 0;
  font-size: var(--fs-body);
  line-height: 1.6;
  color: var(--about-text-main);
}

.data-detail {
  overflow: hidden;
  max-height: 0;
  margin-top: var(--sp-sm);
  padding-top: 0;
  border-top: 2px solid transparent;
  font-size: var(--fs-small);
  font-weight: 700;
  color: var(--brand-blue);
  background: var(--about-card-bg);
  transition: max-height var(--t-med), padding-top var(--t-med), border-color var(--t-med);
}

.data-card:hover .data-detail,
.data-card:focus-within .data-detail {
  max-height: 80px;
  padding-top: var(--sp-sm);
  border-top-color: var(--brand-blue);
}

/* 资质与合作生态 */
.credential-section {
  padding: var(--sp-2xl) 0;
  background: var(--deep-blue);
  color: var(--snow-white);
}

.credential-section .section-heading h2 {
  color: #fff;
}

.credential-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--sp-xl);
  margin-top: var(--sp-xl);
}

.credential-cards {
  margin: 0;
}

.credential-card {
  margin-bottom: var(--sp-md);
  padding: var(--sp-lg);
  background: #0e1c2c;
  border: 1px solid rgba(255, 255, 255, 0.22);
  border-top: 4px solid var(--brand-blue);
  box-shadow: 4px 4px 0 rgba(0, 0, 0, 0.35);
  transition: transform var(--t-fast), box-shadow var(--t-fast), border-color var(--t-fast);
}

.credential-card:hover {
  transform: translate(-2px, -2px);
  border-color: var(--brand-blue);
  box-shadow: 6px 6px 0 var(--brand-blue);
}

.credential-card:last-child {
  margin-bottom: 0;
}

.credential-card h3 {
  margin: var(--sp-sm) 0 var(--sp-xs);
  font-size: var(--fs-h4);
  font-weight: 900;
  line-height: 1.35;
  color: #fff;
}

.credential-card p {
  margin: 0;
  font-size: var(--fs-body);
  line-height: 1.7;
  color: rgba(255, 255, 255, 0.85);
}

.credential-links {
  margin-top: var(--sp-sm);
}

.credential-links a {
  font-weight: 700;
  color: var(--snow-white);
  text-underline-offset: 3px;
}

.credential-links a:hover {
  color: var(--brand-blue);
}

.credential-visual {
  margin: 0;
  border: 2px solid rgba(255, 255, 255, 0.4);
  box-shadow: 8px 8px 0 rgba(30, 136, 229, 0.55);
}

.credential-visual img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 600 / 400;
  object-fit: cover;
  filter: saturate(0.9) contrast(1.05);
}

.credential-visual figcaption {
  padding: var(--sp-sm) var(--sp-md);
  font-size: var(--fs-small);
  color: rgba(255, 255, 255, 0.75);
  background: rgba(255, 255, 255, 0.06);
  border-top: 1px solid rgba(255, 255, 255, 0.2);
}

/* 服务能力带 */
.service-band {
  position: relative;
  padding: var(--sp-2xl) 0;
  background: var(--deep-blue);
  color: var(--snow-white);
  border-top: 4px solid var(--brand-blue);
}

.service-band::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image: linear-gradient(115deg, transparent 0 55%, rgba(255, 255, 255, 0.06) 55% 88%, transparent 88%);
  pointer-events: none;
}

.service-band-inner {
  position: relative;
  z-index: 1;
  display: grid;
  gap: var(--sp-md);
}

.service-band-inner h2 {
  margin: 0;
  font-size: var(--fs-h3);
  font-weight: 900;
  line-height: 1.25;
  color: #fff;
}

.service-band-inner p {
  max-width: 680px;
  margin: 0;
  font-size: var(--fs-body);
  line-height: 1.75;
  color: rgba(255, 255, 255, 0.86);
}

.service-actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--sp-md);
  margin-top: var(--sp-md);
}

.page-about .service-band .btn-ghost {
  border-color: var(--snow-white);
  color: var(--snow-white);
}

.page-about .service-band .btn-ghost:hover {
  background: var(--snow-white);
  color: var(--deep-blue);
}

/* 平板端 */
@media (min-width: 768px) {
  .archive-hero-grid {
    grid-template-columns: minmax(0, 1fr) 260px;
    gap: var(--sp-xl);
  }

  .archive-hero-stamp {
    display: flex;
    align-items: center;
    justify-content: flex-end;
  }

  .stamp-inner {
    position: relative;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    width: 200px;
    height: 200px;
    background: var(--snow-white);
    border: 4px double var(--ink-black);
    box-shadow: var(--shadow-hard);
    transform: rotate(3deg);
  }

  .stamp-inner::before {
    content: "";
    position: absolute;
    inset: 8px;
    border: 1px solid var(--brand-blue);
  }

  .stamp-year {
    padding-bottom: 4px;
    font-size: var(--fs-label);
    font-weight: 700;
    letter-spacing: 0.1em;
    border-bottom: 1px solid var(--ink-black);
  }

  .stamp-name {
    font-size: 56px;
    font-weight: 900;
    line-height: 1;
    color: var(--brand-blue);
  }

  .stamp-sub {
    font-size: 20px;
    font-weight: 900;
    letter-spacing: 0.4em;
    color: var(--ink-black);
  }

  .stamp-coord {
    font-size: 10px;
    color: var(--slate-gray);
  }

  .timeline-index {
    flex-direction: column;
    overflow: visible;
    position: sticky;
    top: 84px;
    align-self: start;
  }

  .timeline-index h3 {
    display: block;
    margin: 0 0 var(--sp-sm);
    font-size: var(--fs-label);
    font-weight: 900;
    letter-spacing: 0.12em;
    color: var(--brand-blue);
    text-transform: uppercase;
  }

  .timeline-index-link {
    display: block;
    padding: 10px 8px;
    border-bottom: 1px dashed rgba(255, 255, 255, 0.18);
    border-radius: 0;
  }

  .timeline-index-link:last-child {
    border-bottom: none;
  }

  .data-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .credential-layout {
    grid-template-columns: minmax(0, 1fr) 380px;
    gap: var(--sp-xl);
    align-items: center;
  }
}

/* 桌面端 */
@media (min-width: 992px) {
  .gene-layout {
    grid-template-columns: minmax(0, 1fr) 440px;
    gap: var(--sp-2xl);
    align-items: center;
  }

  .timeline-layout {
    grid-template-columns: 220px minmax(0, 1fr);
    gap: var(--sp-2xl);
  }

  .data-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .credential-layout {
    grid-template-columns: minmax(0, 1fr) 420px;
    gap: var(--sp-2xl);
  }

  .service-actions {
    margin-top: var(--sp-lg);
  }
}

/* 移动端始终展开数据详情，保证可读性 */
@media (max-width: 767px) {
  .data-detail {
    max-height: none;
    padding-top: var(--sp-sm);
    border-top-color: var(--brand-blue);
  }
}