.page-about {
  --about-rail: 56px;
  --about-gap: 16px;
  display: block;
}

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

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  border-bottom: 1px solid var(--line);
  background:
    radial-gradient(120% 90% at 88% -20%, rgba(232, 184, 75, 0.18), transparent 58%),
    radial-gradient(90% 80% at 0% 0%, rgba(139, 92, 246, 0.16), transparent 60%),
    var(--ink);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image:
    linear-gradient(to right, rgba(42, 58, 107, 0.4) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(42, 58, 107, 0.4) 1px, transparent 1px);
  background-size: 64px 64px;
  opacity: 0.32;
}

.page-about .about-hero .shell {
  position: relative;
  z-index: 1;
  padding-top: 34px;
  padding-bottom: 34px;
}

.page-about .breadcrumb__list a {
  color: var(--mist);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.page-about .breadcrumb__list a:hover,
.page-about .breadcrumb__list a:focus-visible {
  color: var(--gold);
  border-bottom-color: var(--gold);
}

.page-about .about-hero__title {
  margin: 14px 0 18px;
  max-width: 22ch;
  font-family: var(--font-head);
  font-weight: 900;
  font-size: clamp(1.85rem, 6.2vw, 3.1rem);
  line-height: 1.08;
  letter-spacing: -0.02em;
  color: var(--heading);
}

.page-about .about-hero__lede {
  margin: 0 0 22px;
  max-width: 64ch;
  color: var(--text);
  font-size: 1rem;
  line-height: 1.75;
}

.page-about .about-chips {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.page-about .about-toc {
  display: flex;
  gap: 10px;
  margin-top: 30px;
  padding-top: 18px;
  border-top: 1px solid var(--line);
  overflow-x: auto;
  scrollbar-width: none;
  -webkit-overflow-scrolling: touch;
}

.page-about .about-toc::-webkit-scrollbar {
  display: none;
}

.page-about .about-toc__link {
  flex: 0 0 auto;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  min-height: 44px;
  padding: 10px 14px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: rgba(22, 34, 74, 0.6);
  color: var(--text);
  font-size: 0.8125rem;
  line-height: 1.5;
  text-decoration: none;
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease),
    transform var(--dur) var(--ease), background-color var(--dur) var(--ease);
}

.page-about .about-toc__link:hover,
.page-about .about-toc__link:focus-visible {
  color: var(--gold);
  border-color: var(--gold);
  transform: translateY(-2px);
}

.page-about .about-toc__link[data-active] {
  border-color: var(--gold);
  background: rgba(232, 184, 75, 0.14);
  color: var(--gold);
}

.page-about .about-toc__num {
  font-family: var(--font-num);
  font-weight: 700;
  color: var(--gold);
}

/* ---------- 纵向时间脊 ---------- */
.page-about .about-spine {
  position: relative;
  padding: 8px 0 44px;
}

.page-about .about-spine::before {
  content: "";
  position: absolute;
  top: 0;
  bottom: 0;
  left: calc(var(--about-rail) / 2 - 1px);
  width: 1px;
  background: linear-gradient(to bottom,
    transparent,
    rgba(232, 184, 75, 0.75) 6%,
    rgba(232, 184, 75, 0.75) 94%,
    transparent);
}

.page-about .about-chapter {
  position: relative;
  display: grid;
  grid-template-columns: var(--about-rail) minmax(0, 1fr);
  gap: var(--about-gap);
  padding: 40px 0;
}

.page-about .about-rail {
  display: flex;
  justify-content: center;
  align-items: flex-start;
}

.page-about .about-node {
  position: relative;
  z-index: 1;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 48px;
  height: 48px;
  border: 1px solid var(--gold);
  border-radius: var(--radius);
  background: var(--ink);
  color: var(--gold);
  font-family: var(--font-num);
  font-size: 1rem;
  font-weight: 700;
  letter-spacing: 0.02em;
  transition: background-color var(--dur) var(--ease), color var(--dur) var(--ease),
    transform var(--dur) var(--ease);
}

.page-about .about-chapter:hover .about-node,
.page-about .about-chapter:focus-within .about-node {
  background: var(--gold);
  color: var(--ink-deep);
  transform: translateY(2px);
}

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

.page-about .about-title {
  margin: 0 0 16px;
  font-family: var(--font-head);
  font-weight: 900;
  font-size: clamp(1.45rem, 4.4vw, 2.05rem);
  line-height: 1.16;
  letter-spacing: -0.02em;
  color: var(--heading);
}

.page-about .about-subtitle {
  margin: 34px 0 14px;
  padding-left: 12px;
  border-left: 3px solid var(--violet);
  font-family: var(--font-head);
  font-weight: 800;
  font-size: clamp(1.05rem, 2.4vw, 1.25rem);
  line-height: 1.35;
  color: var(--heading);
}

.page-about .about-text {
  margin: 0 0 16px;
  max-width: 70ch;
  color: var(--text);
  line-height: 1.75;
}

.page-about .about-text a {
  color: var(--gold);
  text-decoration: none;
  border-bottom: 1px solid rgba(232, 184, 75, 0.5);
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.page-about .about-text a:hover,
.page-about .about-text a:focus-visible {
  color: var(--gold-soft);
  border-bottom-color: var(--gold-soft);
}

/* ---------- 01 起点 ---------- */
.page-about .about-pains {
  list-style: none;
  margin: 0 0 20px;
  padding: 0;
  display: grid;
  gap: 10px;
  max-width: 70ch;
}

.page-about .about-pains li {
  position: relative;
  padding: 14px 16px 14px 46px;
  border: 1px solid var(--line);
  border-left: 3px solid var(--violet);
  border-radius: var(--radius);
  background: rgba(22, 34, 74, 0.55);
  color: var(--text);
  font-size: 0.9375rem;
  line-height: 1.72;
}

.page-about .about-pains li::before {
  content: "";
  position: absolute;
  left: 19px;
  top: 22px;
  width: 11px;
  height: 11px;
  border: 1px solid var(--gold);
  transform: rotate(45deg);
}

.page-about .about-pains strong {
  color: var(--heading);
  font-weight: 700;
}

/* ---------- 02 团队 ---------- */
.page-about .about-figure {
  margin: 22px 0;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--panel);
  overflow: hidden;
}

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

.page-about .about-figure figcaption {
  padding: 12px 16px;
  border-top: 1px solid var(--line);
  color: var(--mist);
  font-size: 0.8125rem;
  line-height: 1.6;
}

.page-about .about-roles {
  list-style: none;
  margin: 0 0 8px;
  padding: 0;
  display: grid;
  gap: 14px;
}

.page-about .about-role {
  padding: 18px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: linear-gradient(180deg, rgba(22, 34, 74, 0.9), rgba(11, 21, 51, 0.9));
  transition: border-color var(--dur) var(--ease), transform var(--dur) var(--ease);
}

.page-about .about-role:hover {
  border-color: var(--gold);
  transform: translateY(-2px);
}

.page-about .about-role__name {
  display: block;
  margin-bottom: 6px;
  font-family: var(--font-head);
  font-size: 1rem;
  font-weight: 800;
  color: var(--gold);
}

.page-about .about-role__desc {
  margin: 0;
  color: var(--text);
  font-size: 0.9375rem;
  line-height: 1.7;
}

.page-about .about-steps {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 12px;
}

.page-about .about-step {
  display: grid;
  grid-template-columns: 40px minmax(0, 1fr);
  gap: 12px;
  align-items: start;
  padding: 14px 16px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: rgba(22, 34, 74, 0.5);
  transition: border-color var(--dur) var(--ease), transform var(--dur) var(--ease);
}

.page-about .about-step:hover {
  border-color: var(--jade);
  transform: translateY(-2px);
}

.page-about .about-step__num {
  font-family: var(--font-num);
  font-size: 1rem;
  font-weight: 700;
  color: var(--jade);
  line-height: 1.5;
}

.page-about .about-step__title {
  margin: 0 0 4px;
  font-family: var(--font-head);
  font-size: 1rem;
  font-weight: 800;
  color: var(--heading);
}

.page-about .about-step__text {
  margin: 0;
  color: var(--text);
  font-size: 0.9375rem;
  line-height: 1.7;
}

/* ---------- 03 分类体系 ---------- */
.page-about .about-adjust {
  display: grid;
  gap: 14px;
  margin: 0 0 8px;
}

.page-about .about-adjust__item {
  padding: 18px;
  border: 1px solid var(--line);
  border-top: 3px solid var(--violet);
  border-radius: var(--radius);
  background: rgba(22, 34, 74, 0.5);
}

.page-about .about-adjust__tag {
  display: inline-block;
  margin-bottom: 8px;
  font-family: var(--font-num);
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  color: var(--gold);
}

.page-about .about-adjust__item p {
  margin: 0;
  color: var(--text);
  font-size: 0.9375rem;
  line-height: 1.72;
}

.page-about .about-folds {
  display: grid;
  gap: 10px;
}

.page-about .about-fold {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: rgba(22, 34, 74, 0.55);
  overflow: hidden;
  transition: border-color var(--dur) var(--ease);
}

.page-about .about-fold:hover {
  border-color: rgba(232, 184, 75, 0.6);
}

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

.page-about .about-fold__trigger {
  width: 100%;
  min-height: 48px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 12px 16px;
  border: 0;
  background: transparent;
  color: var(--heading);
  font-family: var(--font-head);
  font-size: 0.9375rem;
  font-weight: 700;
  text-align: left;
  cursor: pointer;
  transition: color var(--dur) var(--ease);
}

.page-about .about-fold__trigger:hover {
  color: var(--gold);
}

.page-about .about-fold__trigger:focus-visible {
  outline: 2px solid var(--gold);
  outline-offset: -2px;
}

.page-about .about-fold__mark {
  display: inline-flex;
  align-items: center;
  gap: 9px;
}

.page-about .about-fold__mark::before {
  content: "";
  width: 8px;
  height: 8px;
  border: 1px solid var(--violet);
  transform: rotate(45deg);
  transition: background-color var(--dur) var(--ease);
}

.page-about .about-fold__trigger[aria-expanded="true"] .about-fold__mark::before {
  background: var(--violet);
}

.page-about .about-fold__hint {
  flex: 0 0 auto;
  color: var(--mist);
  font-size: 0.75rem;
  font-weight: 500;
  letter-spacing: 0.04em;
  transition: color var(--dur) var(--ease);
}

.page-about .about-fold__hint::before {
  content: "展开";
}

.page-about .about-fold__trigger[aria-expanded="true"] .about-fold__hint {
  color: var(--gold);
}

.page-about .about-fold__trigger[aria-expanded="true"] .about-fold__hint::before {
  content: "收起";
}

.page-about .about-fold__panel {
  padding: 0 16px 14px;
  color: var(--text);
  font-size: 0.9375rem;
  line-height: 1.72;
}

.page-about .about-fold__panel p {
  margin: 0;
}

/* ---------- 04 设备测试 ---------- */
.page-about .about-matrix {
  margin: 22px 0;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: rgba(22, 34, 74, 0.5);
  overflow-x: auto;
}

.page-about .about-matrix table {
  width: 100%;
  min-width: 640px;
  border-collapse: collapse;
  font-size: 0.875rem;
}

.page-about .about-matrix caption {
  padding: 14px 16px 10px;
  text-align: left;
  color: var(--mist);
  font-size: 0.8125rem;
}

.page-about .about-matrix th,
.page-about .about-matrix td {
  padding: 12px 16px;
  border-top: 1px solid var(--line);
  text-align: left;
  vertical-align: top;
}

.page-about .about-matrix thead th {
  color: var(--gold);
  font-size: 0.8125rem;
  font-weight: 700;
  letter-spacing: 0.02em;
  white-space: nowrap;
}

.page-about .about-matrix tbody th {
  color: var(--heading);
  font-family: var(--font-num);
  font-weight: 700;
  white-space: nowrap;
}

.page-about .about-matrix tbody td {
  color: var(--text);
}

.page-about .about-matrix tbody tr:hover {
  background: rgba(232, 184, 75, 0.06);
}

.page-about .about-checks {
  list-style: none;
  margin: 0 0 18px;
  padding: 0;
  display: grid;
  gap: 12px;
}

.page-about .about-check {
  padding: 16px;
  border: 1px solid var(--line);
  border-top: 3px solid var(--jade);
  border-radius: var(--radius);
  background: rgba(22, 34, 74, 0.5);
}

.page-about .about-check__name {
  display: block;
  margin-bottom: 6px;
  font-family: var(--font-head);
  font-size: 0.9375rem;
  font-weight: 800;
  color: var(--heading);
}

.page-about .about-check__text {
  margin: 0;
  color: var(--text);
  font-size: 0.9rem;
  line-height: 1.7;
}

/* ---------- 05 发展阶段 ---------- */
.page-about .about-milestones {
  display: grid;
  gap: 22px;
  margin: 20px 0 6px;
}

.page-about .about-stages {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 14px;
}

.page-about .about-stage {
  padding: 18px;
  border: 1px solid var(--line);
  border-left: 3px solid var(--violet);
  border-radius: var(--radius);
  background: linear-gradient(180deg, rgba(22, 34, 74, 0.85), rgba(11, 21, 51, 0.85));
  transition: border-left-color var(--dur) var(--ease), transform var(--dur) var(--ease);
}

.page-about .about-stage:hover,
.page-about .about-stage:focus-within {
  border-left-color: var(--gold);
  transform: translateY(-2px);
}

.page-about .about-stage__head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  margin-bottom: 10px;
}

.page-about .about-stage__when {
  font-family: var(--font-num);
  font-size: 0.75rem;
  color: var(--mist);
  letter-spacing: 0.04em;
}

.page-about .about-stage__name {
  margin: 0 0 8px;
  font-family: var(--font-head);
  font-size: 1.05rem;
  font-weight: 800;
  color: var(--heading);
}

.page-about .about-stage__text {
  margin: 0;
  color: var(--text);
  font-size: 0.9375rem;
  line-height: 1.72;
}

.page-about .about-stage-figure {
  margin: 0;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--panel);
  overflow: hidden;
}

.page-about .about-stage-figure img {
  display: block;
  width: 100%;
  object-fit: cover;
}

/* ---------- 06 合作生态 ---------- */
.page-about .about-split {
  display: grid;
  gap: 14px;
  margin: 20px 0 6px;
}

.page-about .about-split__item {
  padding: 20px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: linear-gradient(180deg, rgba(22, 34, 74, 0.9), rgba(11, 21, 51, 0.9));
}

.page-about .about-split__item h3 {
  margin: 0 0 8px;
  font-family: var(--font-head);
  font-size: 1.05rem;
  font-weight: 800;
  color: var(--gold);
}

.page-about .about-split__item p {
  margin: 0;
  color: var(--text);
  font-size: 0.9375rem;
  line-height: 1.72;
}

.page-about .about-cta {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 26px;
}

.page-about .about-cta .btn {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
}

/* ---------- 响应式 ---------- */
@media (min-width: 700px) {
  .page-about .about-roles {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 760px) {
  .page-about .about-folds {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

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

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

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

  .page-about .about-hero .shell {
    padding-top: 62px;
    padding-bottom: 52px;
  }

  .page-about .about-chapter {
    padding: 56px 0;
  }
}

@media (min-width: 900px) {
  .page-about {
    --about-rail: 88px;
    --about-gap: 44px;
  }

  .page-about .about-node {
    width: 56px;
    height: 56px;
    font-size: 1.125rem;
  }

  .page-about .about-milestones {
    grid-template-columns: minmax(0, 1.6fr) minmax(0, 1fr);
    gap: 34px;
    align-items: start;
  }

  .page-about .about-stage-figure {
    position: sticky;
    top: 96px;
  }
}

@media (min-width: 1024px) {
  .page-about .about-chapter--wide .about-body {
    max-width: 1000px;
  }

  .page-about .about-chapter--narrow .about-body {
    max-width: 720px;
  }

  .page-about .about-hero .shell {
    padding-top: 76px;
    padding-bottom: 60px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-toc__link,
  .page-about .about-node,
  .page-about .about-role,
  .page-about .about-step,
  .page-about .about-stage,
  .page-about .about-fold,
  .page-about .about-fold__trigger {
    transition: none;
  }
}