.page-about {
  --about-rail: 190px;
  --about-gap: clamp(28px, 4.5vw, 64px);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  right: -14%;
  bottom: -46%;
  width: min(680px, 92vw);
  height: min(680px, 92vw);
  border-radius: 50%;
  background:
    radial-gradient(circle at 40% 40%, rgba(217, 164, 65, 0.16), transparent 62%),
    radial-gradient(circle at 66% 62%, rgba(79, 195, 232, 0.12), transparent 68%);
  pointer-events: none;
}

.page-about .about-hero .wrap {
  position: relative;
  z-index: 1;
}

.page-about .about-hero .breadcrumb {
  margin-bottom: clamp(30px, 5vw, 52px);
}

.page-about .hero-grid {
  display: grid;
  gap: clamp(34px, 5vw, 58px);
}

.page-about .hero-title {
  margin: 14px 0 0;
  font-size: clamp(2rem, 6.2vw, 3.6rem);
  font-weight: 800;
  line-height: 1.08;
  letter-spacing: -0.02em;
  color: var(--paper);
  max-width: 15em;
}

.page-about .hero-lede {
  margin: clamp(18px, 2.6vw, 26px) 0 0;
  max-width: 34em;
  color: var(--paper-dim);
  font-size: clamp(1rem, 1.7vw, 1.125rem);
  line-height: 1.8;
}

.page-about .about-hero .eyebrow {
  color: var(--gold);
}

.page-about .hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: clamp(24px, 3.4vw, 34px);
}

.page-about .hero-year-block {
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding-bottom: clamp(20px, 3vw, 28px);
  border-bottom: 1px solid var(--line);
}

.page-about .hero-year {
  display: block;
  font-family: var(--font-sans);
  font-size: clamp(5rem, 17vw, 11rem);
  font-weight: 200;
  line-height: 0.78;
  letter-spacing: -0.05em;
  color: var(--gold);
}

.page-about .hero-year-label {
  font-size: 13px;
  letter-spacing: 0.08em;
  color: var(--paper-faint);
}

.page-about .hero-index-nav {
  margin-top: clamp(22px, 3vw, 30px);
}

.page-about .hero-index-title {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.2em;
  color: var(--paper-faint);
}

.page-about .hero-index {
  margin: 0;
  padding: 0;
  list-style: none;
  border-top: 1px solid var(--line-soft);
}

.page-about .hero-index li {
  border-bottom: 1px solid var(--line-soft);
}

.page-about .hero-index a {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 16px;
  padding: 11px 0;
  text-decoration: none;
  color: var(--paper-dim);
  font-size: 14px;
  transition: color 0.2s var(--ease), padding-left 0.2s var(--ease);
}

.page-about .hero-index a:hover,
.page-about .hero-index a:focus-visible {
  color: var(--gold-soft);
  padding-left: 6px;
}

.page-about .hi-num {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--gold);
}

/* ---------- 通用两栏结构 ---------- */
.page-about .flow-grid {
  display: grid;
  gap: clamp(22px, 3.6vw, 34px);
}

.page-about .rail {
  display: flex;
  align-items: baseline;
  gap: 12px;
}

.page-about .rail-index {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.18em;
  color: var(--coral);
}

.page-about .rail-label {
  margin: 0;
  font-size: 13px;
  letter-spacing: 0.14em;
  color: var(--slate);
}

.page-about .section--ink .rail-label {
  color: var(--paper-faint);
}

.page-about .about-h2 {
  margin: 0 0 clamp(18px, 3vw, 26px);
  font-size: clamp(1.6rem, 4.2vw, 2.7rem);
  font-weight: 800;
  line-height: 1.12;
  letter-spacing: -0.02em;
  color: var(--ink);
  max-width: 18em;
}

.page-about .about-h2--ink {
  color: var(--paper);
}

.page-about .about-lead {
  margin: 0 0 clamp(24px, 3.4vw, 34px);
  max-width: 40em;
  font-size: clamp(1rem, 1.5vw, 1.0625rem);
  line-height: 1.8;
  color: var(--slate);
}

.page-about .about-body p {
  margin: 0 0 1.15em;
  max-width: 62ch;
  font-size: 1rem;
  line-height: 1.85;
  color: var(--slate);
}

.page-about .about-body p:last-child {
  margin-bottom: 0;
}

.page-about .media {
  margin: 0;
  overflow: hidden;
  border-radius: var(--radius-organic);
  background: var(--ink-2);
}

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

.page-about .media-caption {
  margin-top: 12px;
  font-family: var(--font-mono);
  font-size: 12px;
  line-height: 1.6;
  letter-spacing: 0.02em;
  color: var(--slate);
}

.page-about .section--ink .media-caption {
  color: var(--paper-faint);
}

/* ---------- 01 品牌起点 ---------- */
.page-about .origin-split {
  display: grid;
  gap: clamp(26px, 4vw, 42px);
}

.page-about .origin-media {
  align-self: start;
}

/* ---------- 02 栏目体系 ---------- */
.page-about .svc-list {
  margin: 0 0 clamp(26px, 4vw, 40px);
  padding: 0;
  list-style: none;
  border-top: 1px solid var(--line-ink);
}

.page-about .svc-item {
  display: grid;
  grid-template-columns: 2.6rem minmax(0, 1fr);
  gap: 10px;
  align-items: baseline;
  padding: 15px 0;
  border-bottom: 1px solid var(--line-ink);
  transition: background-color 0.2s var(--ease);
}

.page-about .svc-num {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--gold);
}

.page-about .svc-name {
  margin: 0 0 5px;
  font-size: 1.0625rem;
  font-weight: 800;
  letter-spacing: -0.01em;
  color: var(--ink);
}

.page-about .svc-desc {
  margin: 0;
  font-size: 0.9375rem;
  line-height: 1.75;
  color: var(--slate);
}

.page-about .columns-media {
  margin-bottom: clamp(26px, 4vw, 40px);
}

.page-about .tree-figure {
  margin: 0;
  padding: clamp(18px, 3vw, 28px);
  border: 1px solid var(--line-ink);
  border-radius: var(--radius-organic);
  background: rgba(244, 239, 230, 0.6);
}

.page-about .tree-scroll {
  overflow-x: auto;
}

.page-about .tree-scroll svg {
  display: block;
  width: 100%;
  min-width: 620px;
  height: auto;
}

.page-about .tree-line {
  fill: none;
  stroke: var(--gold);
  stroke-width: 1.5;
  opacity: 0.55;
}

.page-about .tree-box {
  fill: rgba(18, 22, 28, 0.04);
  stroke: rgba(18, 22, 28, 0.16);
  stroke-width: 1;
}

.page-about .tree-box--root {
  fill: var(--ink);
  stroke: var(--ink);
}

.page-about .tree-box--leaf {
  fill: rgba(79, 195, 232, 0.1);
  stroke: rgba(79, 195, 232, 0.4);
}

.page-about .tree-text {
  font-family: var(--font-sans);
  font-size: 17px;
  font-weight: 600;
  fill: #2a3138;
}

.page-about .tree-text--root {
  fill: var(--paper);
  font-weight: 700;
}

.page-about .tree-text--leaf {
  font-family: var(--font-mono);
  font-size: 15px;
  font-weight: 500;
  fill: #1f3d4a;
}

/* ---------- 03 维护流程 ---------- */
.page-about .steps {
  margin: 0;
  padding: 0;
  list-style: none;
  border-top: 1px solid var(--line-ink);
}

.page-about .step {
  display: grid;
  grid-template-columns: 2.8rem minmax(0, 1fr);
  gap: 12px;
  padding: clamp(18px, 2.8vw, 26px) 0;
  border-bottom: 1px solid var(--line-ink);
}

.page-about .step-num {
  font-family: var(--font-sans);
  font-size: clamp(1.4rem, 3.2vw, 2rem);
  font-weight: 200;
  line-height: 1;
  letter-spacing: -0.03em;
  color: var(--gold);
}

.page-about .step-title {
  margin: 0 0 8px;
  font-size: 1.125rem;
  font-weight: 800;
  letter-spacing: -0.01em;
  color: var(--ink);
}

.page-about .step-body p {
  margin: 0;
  max-width: 58ch;
  font-size: 0.9375rem;
  line-height: 1.8;
  color: var(--slate);
}

/* ---------- 04 时间轴 ---------- */
.page-about .timeline {
  margin: 0;
  padding: 0 0 0 clamp(20px, 3.6vw, 40px);
  list-style: none;
  border-left: 1px solid var(--line);
}

.page-about .tl-item {
  position: relative;
  padding: clamp(16px, 2.6vw, 26px) 0;
  border-bottom: 1px solid var(--line-soft);
}

.page-about .tl-item::before {
  content: "";
  position: absolute;
  top: clamp(30px, 4.6vw, 42px);
  left: calc(-1 * clamp(20px, 3.6vw, 40px) - 4px);
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--gold);
  box-shadow: 0 0 0 4px rgba(217, 164, 65, 0.14);
  transition: background-color 0.24s var(--ease), box-shadow 0.24s var(--ease);
}

.page-about .tl-item:hover::before,
.page-about .tl-item:focus-within::before {
  background: var(--cyan);
  box-shadow: 0 0 0 5px rgba(79, 195, 232, 0.2);
}

.page-about .tl-item:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 4px;
}

.page-about .tl-year {
  display: block;
  font-size: clamp(2.4rem, 8vw, 4.6rem);
  font-weight: 200;
  line-height: 0.9;
  letter-spacing: -0.04em;
  color: var(--paper);
  transition: color 0.24s var(--ease);
}

.page-about .tl-item:hover .tl-year,
.page-about .tl-item:focus-within .tl-year {
  color: var(--gold-soft);
}

.page-about .tl-title {
  margin: 12px 0 0;
  font-size: clamp(1rem, 2.2vw, 1.25rem);
  font-weight: 800;
  letter-spacing: -0.01em;
  color: var(--paper);
}

.page-about .tl-summary {
  max-height: 0;
  overflow: hidden;
  opacity: 0;
  transition: max-height 0.28s var(--ease), opacity 0.24s var(--ease), margin-top 0.28s var(--ease);
}

.page-about .tl-item:hover .tl-summary,
.page-about .tl-item:focus-within .tl-summary {
  max-height: 260px;
  opacity: 1;
  margin-top: 12px;
}

.page-about .tl-summary p {
  margin: 0;
  max-width: 54ch;
  font-size: 0.9375rem;
  line-height: 1.8;
  color: var(--paper-dim);
}

/* ---------- 05 团队与覆盖 ---------- */
.page-about .team-list {
  margin: 0 0 clamp(28px, 4vw, 42px);
  padding: 0;
  list-style: none;
  display: grid;
  gap: 16px;
}

.page-about .team-item {
  padding-left: 16px;
  border-left: 2px solid var(--line);
  transition: border-color 0.2s var(--ease);
}

.page-about .team-item:hover {
  border-left-color: var(--cyan);
}

.page-about .team-name {
  margin: 0 0 6px;
  font-size: 1rem;
  font-weight: 800;
  letter-spacing: -0.01em;
  color: var(--ink);
}

.page-about .team-item p {
  margin: 0;
  max-width: 56ch;
  font-size: 0.9375rem;
  line-height: 1.8;
  color: var(--slate);
}

.page-about .coverage-grid {
  display: grid;
  gap: clamp(18px, 3vw, 26px);
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  padding: clamp(22px, 3.4vw, 32px) 0;
  margin-bottom: clamp(24px, 3.6vw, 36px);
  border-top: 1px solid var(--line-ink);
  border-bottom: 1px solid var(--line-ink);
}

.page-about .big-stat-value {
  display: block;
  font-size: clamp(1.6rem, 4.6vw, 2.9rem);
  font-weight: 200;
  line-height: 1;
  letter-spacing: -0.03em;
  color: var(--clay);
  word-break: keep-all;
}

.page-about .big-stat-label {
  display: block;
  margin-top: 10px;
  font-size: 13px;
  line-height: 1.6;
  color: var(--slate);
}

/* ---------- 06 质量与安全 ---------- */
.page-about .check-list {
  margin: 0;
  padding: 0;
  list-style: none;
  border-top: 1px solid var(--line-ink);
}

.page-about .check-item {
  position: relative;
  padding: clamp(16px, 2.6vw, 24px) 0 clamp(16px, 2.6vw, 24px) 22px;
  border-bottom: 1px solid var(--line-ink);
}

.page-about .check-item::before {
  content: "";
  position: absolute;
  left: 0;
  top: clamp(24px, 3.4vw, 32px);
  width: 8px;
  height: 8px;
  border-radius: 2px;
  background: var(--moss);
}

.page-about .check-title {
  margin: 0 0 8px;
  font-size: 1.0625rem;
  font-weight: 800;
  letter-spacing: -0.01em;
  color: var(--ink);
}

.page-about .check-item p {
  margin: 0;
  max-width: 60ch;
  font-size: 0.9375rem;
  line-height: 1.8;
  color: var(--slate);
}

/* ---------- 结尾 ---------- */
.page-about .about-cta .eyebrow {
  color: var(--coral);
}

.page-about .cta-inner {
  max-width: 46em;
}

.page-about .cta-title {
  margin: 12px 0 0;
  font-size: clamp(1.7rem, 4.4vw, 2.8rem);
  font-weight: 800;
  line-height: 1.14;
  letter-spacing: -0.02em;
  color: var(--paper);
}

.page-about .cta-text {
  margin: clamp(18px, 2.6vw, 24px) 0 0;
  font-size: 1rem;
  line-height: 1.85;
  color: var(--paper-dim);
}

.page-about .cta-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: clamp(24px, 3.4vw, 34px);
}

/* ---------- 响应式 ---------- */
@media (min-width: 720px) {
  .page-about .origin-split {
    grid-template-columns: minmax(0, 1.1fr) minmax(0, 0.9fr);
    align-items: start;
  }
}

@media (min-width: 900px) {
  .page-about .hero-grid {
    grid-template-columns: minmax(0, 1.18fr) minmax(0, 0.82fr);
    align-items: end;
  }

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

@media (min-width: 960px) {
  .page-about .flow-grid {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    gap: var(--about-gap);
  }

  .page-about .rail {
    flex-direction: column;
    align-items: flex-start;
    gap: 10px;
    position: sticky;
    top: calc(var(--header-h) + 28px);
    align-self: start;
  }

  .page-about .flow-main {
    max-width: 940px;
  }

  .page-about .svc-list {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    column-gap: clamp(24px, 3.2vw, 40px);
    border-top: none;
  }

  .page-about .svc-item {
    border-top: 1px solid var(--line-ink);
    padding: 18px 8px 18px 0;
  }

  .page-about .svc-item:hover {
    background: rgba(79, 195, 232, 0.06);
  }
}

@media (hover: none) {
  .page-about .tl-summary {
    max-height: none;
    opacity: 1;
    margin-top: 12px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .tl-summary,
  .page-about .tl-year,
  .page-about .tl-item::before,
  .page-about .hero-index a,
  .page-about .svc-item,
  .page-about .team-item {
    transition: none;
  }
}

</main>