.page-about {
  --about-gap: clamp(22px, 3.6vw, 48px);
  background: var(--c-gravel);
  color: var(--c-deep);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  background: var(--c-blue);
  color: var(--c-fog);
  padding: clamp(20px, 3.4vw, 34px) 0 clamp(30px, 5vw, 56px);
  border-bottom: 4px solid var(--c-volt);
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  inset: 0 0 0 58%;
  background: repeating-linear-gradient(118deg, rgba(31, 199, 182, 0.18) 0 2px, transparent 2px 18px);
  opacity: 0.5;
  pointer-events: none;
}

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

.page-about .about-hero__crumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-size: 13px;
  margin-bottom: clamp(20px, 3vw, 34px);
}

.page-about .about-hero__crumb .breadcrumb__item {
  color: var(--c-line);
  text-decoration: none;
}

.page-about .about-hero__crumb a.breadcrumb__item:hover {
  color: var(--c-volt);
}

.page-about .about-hero__crumb .breadcrumb__item[aria-current="page"] {
  color: var(--c-fog);
}

.page-about .about-hero__grid {
  display: grid;
  gap: clamp(24px, 3.6vw, 40px);
}

.page-about .about-hero__eyebrow {
  margin: 0 0 10px;
  color: var(--c-volt);
}

.page-about .about-hero__title {
  margin: 0 0 18px;
  font-size: clamp(30px, 5.4vw, 52px);
  line-height: 1.1;
  font-weight: 800;
  letter-spacing: -0.02em;
}

.page-about .about-hero__intro {
  margin: 0;
  max-width: 34em;
  font-size: var(--fs-1);
  line-height: 1.8;
  color: var(--c-line);
}

.page-about .about-hero__stats {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(104px, 1fr));
  gap: 10px;
}

.page-about .about-stat {
  border: 2px solid var(--c-line);
  background: var(--c-ink);
  padding: 12px 12px 14px;
}

.page-about .about-stat__num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(22px, 3vw, 30px);
  font-weight: 700;
  line-height: 1.05;
  letter-spacing: -0.01em;
  color: var(--c-volt);
}

.page-about .about-stat__label {
  display: block;
  margin-top: 6px;
  font-size: 13px;
  line-height: 1.5;
  color: var(--c-line);
}

.page-about .about-hero__figure {
  margin: clamp(26px, 4vw, 44px) 0 0;
}

.page-about .about-hero__figure img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
  border: 2px solid var(--c-line);
}

.page-about .about-hero__figure .figure__cap {
  margin-top: 10px;
  font-size: 13px;
  line-height: 1.6;
  color: var(--c-line);
}

/* ---------- 通用区块 ---------- */
.page-about .section {
  padding: clamp(42px, 6vw, 78px) 0;
}

.page-about .about-head {
  max-width: 44em;
}

.page-about .about-h2 {
  margin: 8px 0 14px;
  font-size: clamp(24px, 3.4vw, 36px);
  line-height: 1.18;
  font-weight: 800;
  letter-spacing: -0.02em;
}

.page-about .about-lead {
  margin: 0;
  max-width: 38em;
  font-size: var(--fs-1);
  line-height: 1.8;
  color: var(--c-steel);
}

/* ---------- 三组分工 ---------- */
.page-about .about-rows {
  list-style: none;
  margin: clamp(26px, 3.6vw, 40px) 0 0;
  padding: 0;
  border-top: 2px solid var(--c-deep);
}

.page-about .about-row {
  display: grid;
  grid-template-columns: 56px minmax(0, 1fr);
  gap: 4px 14px;
  padding: 20px 4px;
  border-bottom: 2px solid var(--c-deep);
  transition: background-color 0.18s ease, box-shadow 0.18s ease;
}

.page-about .about-row__num {
  font-family: var(--font-mono);
  font-size: var(--fs-3);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--c-steel);
  transition: color 0.18s ease;
}

.page-about .about-row__body {
  min-width: 0;
}

.page-about .about-row__title {
  margin: 0 0 8px;
  font-size: var(--fs-2);
  font-weight: 800;
  letter-spacing: -0.01em;
}

.page-about .about-row__text {
  margin: 0;
  max-width: 38em;
  font-size: 16px;
  line-height: 1.78;
}

.page-about .about-row__metric {
  grid-column: 2;
  margin: 12px 0 0;
  padding-left: 12px;
  border-left: 4px solid var(--c-steel);
  font-family: var(--font-mono);
  font-size: 13px;
  line-height: 1.6;
  color: var(--c-steel);
  transition: color 0.18s ease, border-color 0.18s ease;
}

.page-about .about-row:hover,
.page-about .about-row:focus-within {
  background: var(--c-fog);
  box-shadow: inset 6px 0 0 var(--c-volt);
}

.page-about .about-row:hover .about-row__num,
.page-about .about-row:focus-within .about-row__num {
  color: var(--c-volt);
}

.page-about .about-row:hover .about-row__metric,
.page-about .about-row:focus-within .about-row__metric {
  color: var(--c-deep);
  border-color: var(--c-volt);
}

/* ---------- 编制流程 ---------- */
.page-about .about-flow {
  background: var(--c-fog);
  border-top: 2px solid var(--c-deep);
  border-bottom: 2px solid var(--c-deep);
}

.page-about .about-flow__grid {
  display: grid;
  gap: clamp(26px, 4vw, 46px);
  margin-top: clamp(26px, 3.6vw, 40px);
}

.page-about .about-steps {
  list-style: none;
  margin: 0;
  padding: 0;
  position: relative;
}

.page-about .about-steps::before {
  content: "";
  position: absolute;
  left: 8px;
  top: 14px;
  bottom: 22px;
  width: 2px;
  background: var(--c-line);
}

.page-about .about-step {
  position: relative;
  padding: 0 0 26px 40px;
}

.page-about .about-step:last-child {
  padding-bottom: 0;
}

.page-about .about-step::before {
  content: "";
  position: absolute;
  left: 0;
  top: 3px;
  width: 14px;
  height: 14px;
  background: var(--c-volt);
  border: 2px solid var(--c-deep);
  transform: rotate(45deg);
}

.page-about .about-step__num {
  display: block;
  margin-bottom: 6px;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.08em;
  color: var(--c-steel);
}

.page-about .about-step__title {
  margin: 0 0 8px;
  font-size: var(--fs-2);
  font-weight: 800;
  letter-spacing: -0.01em;
}

.page-about .about-step__text {
  margin: 0;
  max-width: 36em;
  font-size: 16px;
  line-height: 1.78;
}

.page-about .about-flow__figure {
  margin: 0;
}

.page-about .about-flow__figure img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
  border: 2px solid var(--c-deep);
  box-shadow: var(--hard-sm);
}

.page-about .about-flow__figure .figure__cap {
  margin-top: 10px;
  font-size: 13px;
  line-height: 1.6;
  color: var(--c-steel);
}

/* ---------- 发展历程（分段切换） ---------- */
.page-about .about-timeline {
  display: grid;
  gap: 22px;
  margin-top: clamp(26px, 3.6vw, 40px);
}

.page-about .about-timeline__list {
  display: flex;
  gap: 10px;
  overflow-x: auto;
  padding-bottom: 8px;
}

.page-about .tabs__btn {
  flex: 0 0 auto;
  min-width: 96px;
  padding: 10px 16px;
  font-family: var(--font-mono);
  font-size: var(--fs-2);
  font-weight: 700;
  text-align: left;
  color: var(--c-deep);
  background: var(--c-fog);
  border: 2px solid var(--c-deep);
  cursor: pointer;
  transition: background-color 0.18s ease, color 0.18s ease, box-shadow 0.18s ease;
}

.page-about .tabs__btn:hover {
  background: var(--c-line);
}

.page-about .tabs__btn[aria-selected="true"] {
  color: var(--c-fog);
  background: var(--c-blue);
  box-shadow: inset 6px 0 0 var(--c-volt), var(--hard-sm);
}

.page-about .about-timeline__panels {
  min-width: 0;
}

.page-about .tabs__panel {
  min-width: 0;
  background: var(--c-fog);
  border: 2px solid var(--c-deep);
  box-shadow: var(--hard);
  padding: clamp(20px, 3vw, 34px);
}

.page-about .tabs__panel + .tabs__panel {
  margin-top: 18px;
}

.page-about .about-timeline__title {
  margin: 0 0 12px;
  font-size: var(--fs-3);
  font-weight: 800;
  letter-spacing: -0.01em;
}

.page-about .about-timeline__panel p {
  margin: 0 0 14px;
  max-width: 40em;
  font-size: 16px;
  line-height: 1.78;
}

.page-about .about-timeline__meta {
  margin: 0;
  padding-top: 12px;
  border-top: 2px solid var(--c-line);
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--c-steel);
}

/* ---------- 协作网络 ---------- */
.page-about .about-network__grid {
  display: grid;
  gap: clamp(24px, 4vw, 44px);
}

.page-about .about-network__text {
  margin: 0;
  max-width: 38em;
  font-size: 16px;
  line-height: 1.78;
}

.page-about .about-points {
  list-style: none;
  margin: 22px 0 0;
  padding: 0;
}

.page-about .about-points li {
  position: relative;
  padding: 0 0 14px 24px;
  font-size: 16px;
  line-height: 1.75;
}

.page-about .about-points li:last-child {
  padding-bottom: 0;
}

.page-about .about-points li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 9px;
  width: 10px;
  height: 10px;
  background: var(--c-volt);
  border: 2px solid var(--c-deep);
}

.page-about .about-points strong {
  font-weight: 800;
}

.page-about .about-network__figure {
  margin: 0;
}

.page-about .about-network__figure img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
  border: 2px solid var(--c-deep);
  box-shadow: var(--hard);
}

.page-about .about-network__figure .figure__cap {
  margin-top: 10px;
  font-size: 13px;
  line-height: 1.6;
  color: var(--c-steel);
}

/* ---------- 编辑规范 ---------- */
.page-about .about-keep__intro {
  margin-bottom: clamp(24px, 3.6vw, 40px);
}

.page-about .about-keep__list {
  list-style: none;
  margin: 0;
  padding: 0;
  border-bottom: 2px solid var(--c-deep);
}

.page-about .about-keep__item {
  display: grid;
  gap: 6px 24px;
  padding: 18px 0;
  border-top: 2px solid var(--c-deep);
}

.page-about .about-keep__key {
  font-family: var(--font-mono);
  font-size: 14px;
  letter-spacing: 0.04em;
  color: var(--c-blue);
}

.page-about .about-keep__item p {
  margin: 0;
  max-width: 42em;
  font-size: 16px;
  line-height: 1.78;
}

/* ---------- 收束 ---------- */
.page-about .about-cta {
  padding: 0 0 clamp(48px, 7vw, 88px);
}

.page-about .about-cta__panel {
  display: grid;
  gap: 16px;
  padding: clamp(26px, 4.4vw, 52px);
  background: var(--c-ink);
  color: var(--c-gravel);
  border: 2px solid var(--c-deep);
  border-top: 6px solid var(--c-volt);
  box-shadow: var(--hard);
}

.page-about .about-cta__eyebrow {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.1em;
  color: var(--c-volt);
}

.page-about .about-cta__title {
  margin: 0;
  font-size: clamp(22px, 3.2vw, 34px);
  line-height: 1.2;
  font-weight: 800;
  letter-spacing: -0.02em;
}

.page-about .about-cta__text {
  margin: 0;
  max-width: 40em;
  font-size: 16px;
  line-height: 1.78;
  color: var(--c-line);
}

.page-about .about-cta__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 6px;
}

.page-about .about-cta__actions .btn {
  text-decoration: none;
}

.page-about .about-cta__panel .btn--ghost {
  color: var(--c-gravel);
  border-color: var(--c-gravel);
}

/* ---------- 桌面布局 ---------- */
@media (min-width: 880px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1.6fr) minmax(0, 1fr);
    align-items: end;
    gap: clamp(36px, 5vw, 80px);
  }

  .page-about .about-row {
    grid-template-columns: 84px minmax(0, 1fr) 240px;
    gap: 0 28px;
    align-items: start;
    padding: 24px 16px 24px 6px;
  }

  .page-about .about-row__metric {
    grid-column: 3;
    margin-top: 8px;
  }

  .page-about .about-flow__grid {
    grid-template-columns: minmax(0, 1fr) 292px;
    gap: clamp(30px, 4.5vw, 62px);
    align-items: start;
  }

  .page-about .about-timeline {
    grid-template-columns: 180px minmax(0, 1fr);
    gap: clamp(24px, 4vw, 56px);
    align-items: start;
  }

  .page-about .about-timeline__list {
    flex-direction: column;
    overflow: visible;
    padding-bottom: 0;
  }

  .page-about .about-network__grid {
    grid-template-columns: minmax(0, 0.92fr) minmax(0, 1.08fr);
    align-items: center;
    gap: clamp(30px, 5vw, 64px);
  }

  .page-about .about-cta__panel {
    grid-template-columns: minmax(0, 1fr);
    padding-left: clamp(36px, 5vw, 64px);
    padding-right: clamp(36px, 5vw, 64px);
  }
}

@media (min-width: 760px) and (max-width: 879px) {
  .page-about .about-keep__item {
    grid-template-columns: 150px minmax(0, 1fr);
    align-items: baseline;
  }
}

@media (min-width: 880px) {
  .page-about .about-keep__item {
    grid-template-columns: 150px minmax(0, 1fr);
    align-items: baseline;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about * {
    transition: none !important;
    animation: none !important;
  }
}