.page-about {
  --about-rail: var(--navy-700);
  --about-rail-dark: #1d4f68;
  --about-rule: rgba(220, 184, 120, 0.42);
  --about-line-dark: rgba(220, 184, 120, 0.22);
  --about-line: rgba(15, 61, 85, 0.18);
  background-color: var(--navy-900);
  color: var(--ink);
}

.page-about img {
  max-width: 100%;
  height: auto;
}

.page-about a:focus-visible,
.page-about .btn:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 3px;
}

/* ============ 首屏 ============ */
.page-about .about-hero {
  position: relative;
  padding: clamp(24px, 4vw, 44px) 0 clamp(44px, 7vw, 88px);
  background-color: var(--navy-900);
  background-image:
    repeating-linear-gradient(118deg, rgba(30, 110, 140, 0.18) 0 1px, transparent 1px 42px),
    radial-gradient(130% 90% at 8% -10%, rgba(30, 110, 140, 0.5), transparent 62%);
  color: var(--paper);
}

.page-about .breadcrumb-list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 0;
  padding: 0;
  list-style: none;
  font-size: var(--fs-12);
  color: var(--mist-dark);
  letter-spacing: 0.04em;
}

.page-about .breadcrumb-list li + li::before {
  content: "／";
  margin-right: 8px;
  color: var(--navy-700);
}

.page-about .breadcrumb-list a {
  color: var(--sand);
  text-decoration: none;
}

.page-about .breadcrumb-list a:hover {
  color: var(--paper);
  text-decoration: underline;
  text-underline-offset: 4px;
}

.page-about .hero-grid {
  display: grid;
  gap: clamp(28px, 5vw, 52px);
  margin-top: clamp(26px, 5vw, 52px);
}

.page-about .hero-kicker {
  margin: 0 0 18px;
  font-size: var(--fs-12);
  letter-spacing: 0.22em;
  color: var(--sand);
}

.page-about .about-hero h1 {
  margin: 0 0 22px;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: var(--fs-56);
  line-height: 1.04;
  letter-spacing: -0.01em;
  color: var(--paper);
  max-width: 18em;
}

.page-about .about-hero .lede {
  margin: 0;
  max-width: 34em;
  font-size: var(--fs-16);
  line-height: 1.75;
  color: var(--mist-dark);
}

.page-about .hero-stats {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background-color: var(--about-line-dark);
  border: 1px solid var(--about-line-dark);
}

.page-about .hero-stats li {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 16px 14px;
  background-color: rgba(8, 40, 56, 0.92);
}

.page-about .stat-num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: var(--fs-26);
  line-height: 1.1;
  color: var(--cyan);
}

.page-about .stat-label {
  font-size: var(--fs-12);
  letter-spacing: 0.08em;
  color: var(--mist-dark);
}

/* ============ 章节索引条 ============ */
.page-about .about-index {
  background-color: var(--navy-800);
  border-top: 1px solid var(--about-line-dark);
  border-bottom: 1px solid var(--about-line-dark);
}

.page-about .about-index-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  gap: 4px;
  overflow-x: auto;
  scrollbar-width: thin;
}

.page-about .about-index-list li {
  flex: 0 0 auto;
}

.page-about .about-index-list a {
  display: flex;
  align-items: center;
  gap: 10px;
  min-height: 48px;
  padding: 0 14px;
  font-size: var(--fs-14);
  color: var(--mist-dark);
  text-decoration: none;
  white-space: nowrap;
  border-bottom: 2px solid transparent;
  transition: color 180ms var(--ease), border-color 180ms var(--ease);
}

.page-about .about-index-list a:hover,
.page-about .about-index-list a:focus-visible {
  color: var(--paper);
  border-bottom-color: var(--sand);
}

.page-about .about-index-list .mono {
  font-family: var(--font-mono);
  font-size: var(--fs-12);
  color: var(--sand);
}

/* ============ 章节骨架 ============ */
.page-about .chapter {
  padding: clamp(48px, 8vw, 108px) 0;
}

.page-about .chapter-grid {
  display: grid;
  gap: clamp(20px, 4vw, 40px);
}

.page-about .chapter-rail {
  display: flex;
  align-items: baseline;
  gap: 16px;
}

.page-about .rail-no {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: var(--fs-56);
  line-height: 0.9;
  letter-spacing: -0.02em;
  font-variant-numeric: tabular-nums;
  color: var(--about-rail);
}

.page-about .ch-title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: var(--fs-26);
  line-height: 1.24;
  color: var(--ink);
}

.page-about .chapter-body > p {
  margin: 0 0 8px;
  max-width: 34em;
  font-size: var(--fs-16);
  line-height: 1.75;
}

.page-about .band-paper {
  background-color: var(--paper);
  color: var(--ink);
}

.page-about .band-paper .rail-no {
  color: var(--about-rail);
}

.page-about .band-dark {
  background-color: var(--navy-900);
  color: var(--paper);
}

.page-about .band-dark.band-alt {
  background-color: var(--navy-800);
  background-image: linear-gradient(180deg, rgba(4, 20, 31, 0.65), rgba(8, 40, 56, 0.15));
}

.page-about .band-dark .rail-no {
  color: var(--about-rail-dark);
}

.page-about .band-dark .ch-title,
.page-about .band-dark .chapter-body h3 {
  color: var(--paper);
}

.page-about .band-dark .chapter-body > p,
.page-about .band-dark .chapter-body p,
.page-about .band-dark .chapter-body li {
  color: var(--mist-dark);
}

.page-about .chapter-body a {
  color: var(--orange-deep);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.page-about .band-dark .chapter-body a,
.page-about .band-dark .team-card a {
  color: var(--sand);
}

/* ============ 01 三根支柱 ============ */
.page-about .pillars {
  display: grid;
  gap: 22px;
  margin-top: 32px;
}

.page-about .pillar {
  padding-top: 16px;
  border-top: 2px solid var(--navy-700);
}

.page-about .pillar-index {
  display: block;
  font-family: var(--font-mono);
  font-size: var(--fs-12);
  letter-spacing: 0.14em;
  color: var(--orange-deep);
}

.page-about .pillar h3 {
  margin: 10px 0 8px;
  font-size: var(--fs-20);
  font-weight: 700;
  line-height: 1.35;
}

.page-about .pillar p {
  margin: 0;
  font-size: var(--fs-14);
  line-height: 1.75;
  color: #46525d;
}

/* ============ 02 使用时刻 ============ */
.page-about .moments {
  list-style: none;
  margin: 30px 0 0;
  padding: 0;
  display: grid;
  gap: 16px;
}

.page-about .moment {
  padding: 22px 20px;
  background-color: rgba(4, 20, 31, 0.78);
  border-left: 3px solid var(--sand);
  border-radius: 0 18px 18px 0;
}

.page-about .moment-time {
  display: inline-block;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: var(--fs-20);
  color: var(--cyan);
  letter-spacing: 0.04em;
}

.page-about .moment h3 {
  margin: 8px 0 10px;
  font-size: var(--fs-20);
  line-height: 1.35;
}

.page-about .moment p {
  margin: 0;
  font-size: var(--fs-14);
  line-height: 1.75;
}

/* ============ 03 流程 ============ */
.page-about .flow {
  list-style: none;
  margin: 34px 0 0;
  padding: 0;
  display: grid;
  gap: 26px;
}

.page-about .flow-step {
  position: relative;
  padding-left: 34px;
}

.page-about .flow-step::before {
  content: "";
  position: absolute;
  left: 9px;
  top: 16px;
  bottom: -26px;
  border-left: 1px dashed var(--sand);
  opacity: 0.7;
}

.page-about .flow-step:last-child::before {
  display: none;
}

.page-about .flow-node {
  position: absolute;
  left: 0;
  top: 2px;
  width: 20px;
  height: 20px;
  border-radius: 50%;
  border: 2px solid var(--sand);
  background-color: var(--paper);
  box-shadow: inset 0 0 0 3px var(--paper), inset 0 0 0 4px var(--navy-700);
}

.page-about .flow-time {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: var(--fs-12);
  letter-spacing: 0.08em;
  color: var(--orange-deep);
}

.page-about .flow-step h3 {
  margin: 8px 0 8px;
  font-size: var(--fs-20);
  line-height: 1.3;
}

.page-about .flow-step p {
  margin: 0;
  font-size: var(--fs-14);
  line-height: 1.72;
  color: #46525d;
  max-width: 30em;
}

.page-about .flow-tail {
  margin: 26px 0 0;
  font-size: var(--fs-14);
  line-height: 1.75;
  color: #46525d;
  max-width: 34em;
}

/* ============ 图片框 ============ */
.page-about .media-frame {
  margin: 30px 0 0;
  overflow: hidden;
  background-color: var(--navy-800);
  border: 1px solid var(--about-line-dark);
  border-radius: 24px 6px 24px 6px;
}

.page-about .media-frame img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.page-about .media-frame figcaption {
  padding: 12px 16px;
  font-size: var(--fs-12);
  line-height: 1.6;
  color: var(--mist-dark);
  background-color: var(--navy-900);
}

.page-about .media-flow {
  aspect-ratio: 14 / 9;
}

.page-about .media-flow figcaption {
  aspect-ratio: auto;
}

.page-about .media-tech {
  aspect-ratio: 3 / 2;
  margin-top: 24px;
}

.page-about .media-era {
  aspect-ratio: 16 / 7;
  margin-top: 26px;
  border-color: rgba(220, 184, 120, 0.3);
}

/* ============ 04 技术四层 ============ */
.page-about .tech-grid {
  display: grid;
  gap: 26px;
  margin-top: 26px;
}

.page-about .layers {
  display: grid;
  gap: 1px;
  background-color: var(--about-line-dark);
  border-top: 1px solid var(--about-line-dark);
}

.page-about .layer {
  padding: 18px 4px 18px 0;
  background-color: var(--navy-900);
}

.page-about .band-alt .layer {
  background-color: transparent;
}

.page-about .layer-no {
  display: block;
  font-family: var(--font-mono);
  font-size: var(--fs-12);
  letter-spacing: 0.16em;
  color: var(--orange);
}

.page-about .layer h3 {
  margin: 8px 0 6px;
  font-size: var(--fs-20);
  line-height: 1.3;
}

.page-about .layer p {
  margin: 0;
  font-size: var(--fs-14);
  line-height: 1.72;
  max-width: 30em;
}

/* ============ 05 时间轴 ============ */
.page-about .timeline {
  list-style: none;
  margin: 26px 0 0;
  padding: 0 0 12px;
  display: grid;
  grid-auto-flow: column;
  grid-auto-columns: 84%;
  gap: 14px;
  overflow-x: auto;
  scroll-snap-type: x mandatory;
  scrollbar-width: thin;
}

.page-about .timeline li {
  scroll-snap-align: start;
  padding: 22px 20px;
  background-color: rgba(4, 20, 31, 0.82);
  border: 1px solid var(--about-line-dark);
  border-radius: 18px 4px 18px 4px;
}

.page-about .era {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: var(--fs-12);
  letter-spacing: 0.1em;
  color: var(--sand);
  border: 1px solid var(--about-rule);
  border-radius: 999px;
  padding: 3px 10px;
}

.page-about .timeline h3 {
  margin: 12px 0 8px;
  font-size: var(--fs-20);
  line-height: 1.3;
}

.page-about .timeline p {
  margin: 0;
  font-size: var(--fs-14);
  line-height: 1.72;
}

/* ============ 06 团队 ============ */
.page-about .team {
  display: grid;
  gap: 18px;
  margin-top: 30px;
}

.page-about .team-card {
  padding: 26px 24px;
  border-radius: var(--radius-blob);
}

.page-about .team-card h3 {
  margin: 8px 0 10px;
  font-size: var(--fs-20);
  line-height: 1.3;
  font-weight: 700;
}

.page-about .team-card p {
  margin: 0;
  font-size: var(--fs-14);
  line-height: 1.75;
}

.page-about .team-num {
  display: inline-block;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: var(--fs-26);
  line-height: 1.1;
}

.page-about .team-card--a {
  background-color: var(--navy-800);
  color: var(--paper);
}

.page-about .team-card--a .team-num {
  color: var(--cyan);
}

.page-about .team-card--a p {
  color: var(--mist-dark);
}

.page-about .team-card--b {
  background-color: rgba(30, 110, 140, 0.14);
  border: 1px solid rgba(30, 110, 140, 0.4);
  color: var(--ink);
}

.page-about .team-card--b .team-num {
  color: var(--tide);
}

.page-about .team-card--b p {
  color: #33414d;
}

.page-about .team-card--c {
  background-color: rgba(220, 184, 120, 0.28);
  border: 1px solid rgba(220, 184, 120, 0.7);
  color: var(--ink);
}

.page-about .team-card--c .team-num {
  color: var(--orange-deep);
}

.page-about .team-card--c p {
  color: #33414d;
}

.page-about .team-rhythm {
  margin: 28px 0 0;
  padding-top: 18px;
  border-top: 1px solid var(--about-line);
  font-size: var(--fs-14);
  line-height: 1.75;
  color: #46525d;
  max-width: 34em;
}

/* ============ 07 服务标准 ============ */
.page-about .standards {
  display: grid;
  gap: 1px;
  margin: 30px 0 0;
  background-color: var(--about-line-dark);
  border-top: 1px solid var(--about-line-dark);
  border-bottom: 1px solid var(--about-line-dark);
}

.page-about .standard {
  padding: 20px 2px 20px 0;
  background-color: var(--navy-900);
}

.page-about .standard dt {
  font-size: var(--fs-12);
  letter-spacing: 0.12em;
  color: var(--sand);
}

.page-about .standard dd {
  margin: 10px 0 0;
  font-size: var(--fs-14);
  line-height: 1.72;
  color: var(--mist-dark);
  max-width: 26em;
}

.page-about .standard-num {
  display: block;
  margin-bottom: 6px;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: var(--fs-36);
  line-height: 1.05;
  color: var(--orange);
}

/* ============ 收尾 ============ */
.page-about .about-cta {
  padding: clamp(44px, 7vw, 84px) 0;
  background-color: var(--navy-800);
  background-image: linear-gradient(115deg, rgba(255, 90, 31, 0.16), transparent 58%);
  border-top: 1px solid var(--about-line-dark);
}

.page-about .about-cta-inner {
  display: grid;
  gap: 26px;
}

.page-about .about-cta h2 {
  margin: 0;
  max-width: 24em;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: var(--fs-26);
  line-height: 1.35;
  color: var(--paper);
}

.page-about .about-cta-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.page-about .about-cta-actions .btn {
  min-height: 48px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0 22px;
  text-decoration: none;
}

/* ============ 响应式 ============ */
@media (min-width: 760px) {
  .page-about .hero-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .pillars {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 26px;
  }

  .page-about .moments {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 18px;
  }

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

  .page-about .standard {
    padding: 24px 22px 24px 0;
  }

  .page-about .standard:nth-child(even) {
    padding-left: 22px;
  }
}

@media (min-width: 900px) {
  .page-about .hero-grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 4fr);
    align-items: end;
    gap: 56px;
  }

  .page-about .chapter-grid {
    grid-template-columns: minmax(0, 3.4fr) minmax(0, 8.6fr);
    gap: clamp(36px, 5vw, 72px);
    align-items: start;
  }

  .page-about .chapter-rail {
    display: block;
    position: sticky;
    top: 104px;
  }

  .page-about .rail-no {
    display: block;
    font-size: var(--fs-88);
  }

  .page-about .rail-no::after {
    content: "";
    display: block;
    width: 56px;
    height: 1px;
    margin-top: 20px;
    background-color: var(--about-rule);
  }

  .page-about .ch-title {
    margin-top: 18px;
  }

  .page-about .flow {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 22px;
  }

  .page-about .flow-step {
    padding-left: 0;
    padding-top: 34px;
  }

  .page-about .flow-step::before {
    left: 26px;
    right: -22px;
    top: 9px;
    bottom: auto;
    border-left: 0;
    border-top: 1px dashed var(--sand);
  }

  .page-about .flow-node {
    left: 0;
    top: 0;
  }

  .page-about .flow-step p {
    max-width: none;
  }

  .page-about .tech-grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 4fr);
    gap: 40px;
    align-items: start;
  }

  .page-about .media-tech {
    margin-top: 0;
  }

  .page-about .timeline {
    grid-auto-flow: row;
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 16px;
    overflow-x: visible;
    padding-bottom: 0;
  }

  .page-about .team {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 20px;
    align-items: start;
  }

  .page-about .team-card--b {
    margin-top: 30px;
  }

  .page-about .team-card--c {
    margin-top: 58px;
  }

  .page-about .about-cta-inner {
    grid-template-columns: minmax(0, 7fr) minmax(0, 4fr);
    align-items: end;
    gap: 40px;
  }

  .page-about .about-cta-actions {
    justify-content: flex-end;
  }
}

@media (max-width: 700px) {
  .page-about .timeline {
    grid-auto-flow: row;
    grid-auto-columns: auto;
    overflow-x: visible;
  }

  .page-about .about-index-list {
    padding-bottom: 2px;
  }

  .page-about .media-flow {
    aspect-ratio: 4 / 3;
  }

  .page-about .media-era {
    aspect-ratio: 3 / 2;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-index-list a {
    transition: none;
  }
}
<<<END>>>