.page-about {
  --coverage-ink: #202020;
  --coverage-line: rgba(255, 255, 255, 0.18);
  background: var(--bg-deep);
}

/* ===== Hero ===== */
.page-about .coverage-hero {
  position: relative;
  overflow: hidden;
  padding: 28px 0 52px;
  background: var(--bg-deep);
}
.page-about .coverage-hero::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 4px;
  background: linear-gradient(90deg, var(--accent-yellow), var(--accent-coral));
  z-index: 1;
}
.page-about .coverage-hero::after {
  content: "";
  position: absolute;
  right: -70px;
  top: 30px;
  width: 280px;
  height: 280px;
  background: repeating-linear-gradient(45deg, rgba(255, 255, 255, 0.05) 0 2px, transparent 2px 12px);
  clip-path: var(--cut-corner);
  pointer-events: none;
}
.page-about .coverage-hero__breadcrumb {
  margin-bottom: 30px;
}
.page-about .coverage-hero__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 30px;
}
.page-about .coverage-hero__copy {
  position: relative;
  z-index: 1;
}
.page-about .coverage-hero__kicker {
  font-family: var(--font-display);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--accent-yellow);
  margin: 0 0 12px;
  text-transform: uppercase;
}
.page-about .coverage-hero__title {
  font-family: var(--font-display);
  font-size: clamp(28px, 6vw, 48px);
  line-height: 1.14;
  margin: 0 0 18px;
  max-width: 12em;
  color: var(--text-light);
}
.page-about .coverage-hero__lead {
  font-size: 15px;
  line-height: 1.75;
  color: var(--text-muted);
  max-width: 56em;
  margin: 0 0 26px;
}
.page-about .coverage-hero__stats {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 10px;
  max-width: 600px;
}
.page-about .coverage-hero__stat {
  background: rgba(255, 255, 255, 0.07);
  border-left: 3px solid var(--accent-yellow);
  padding: 12px 14px;
  display: flex;
  flex-direction: column;
  gap: 3px;
  transition: background var(--ease), transform var(--ease);
}
.page-about .coverage-hero__stat:hover {
  background: rgba(255, 255, 255, 0.14);
  transform: translateY(-2px);
}
.page-about .coverage-hero__stat:nth-child(even) {
  border-left-color: var(--accent-coral);
}
.page-about .coverage-hero__num {
  font-family: var(--font-display);
  font-size: 26px;
  line-height: 1.1;
  color: var(--accent-yellow);
}
.page-about .coverage-hero__label {
  font-size: 12px;
  color: var(--text-muted);
}
.page-about .coverage-hero__figure {
  margin: 0;
  position: relative;
  z-index: 1;
  background: var(--bg-green);
  clip-path: var(--cut-corner);
  padding: 10px;
  align-self: center;
}
.page-about .coverage-hero__img {
  width: 100%;
  height: auto;
  display: block;
  aspect-ratio: 3 / 2;
  object-fit: cover;
}

/* ===== Section heads ===== */
.page-about .coverage-head {
  display: flex;
  align-items: flex-start;
  gap: 16px;
  margin-bottom: 30px;
}
.page-about .coverage-head__index {
  font-family: var(--font-display);
  font-size: 42px;
  line-height: 0.9;
  color: var(--accent-yellow);
  flex-shrink: 0;
}
.page-about .coverage-head__title {
  font-family: var(--font-display);
  font-size: clamp(24px, 4vw, 34px);
  margin: 0 0 6px;
  color: var(--text-light);
}
.page-about .coverage-head__desc {
  font-size: 14px;
  margin: 0;
  color: var(--text-muted);
}

/* ===== 收录范围 ===== */
.page-about .coverage-scope {
  background: var(--bg-deep);
  padding: 48px 0;
}
.page-about .coverage-scope__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
}
.page-about .coverage-scope__card {
  position: relative;
  background: var(--card-warm);
  clip-path: var(--cut-corner);
  padding: 20px 22px;
  display: flex;
  flex-direction: column;
  gap: 12px;
  transition: transform var(--ease), box-shadow var(--ease);
}
.page-about .coverage-scope__card:nth-child(even) {
  background: var(--card-orange);
}
.page-about .coverage-scope__card:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 20px var(--shadow-main);
}
.page-about .coverage-scope__card--focus::after {
  content: "";
  position: absolute;
  top: 12px;
  right: 12px;
  width: 10px;
  height: 10px;
  background: var(--accent-coral);
  clip-path: polygon(50% 0, 100% 50%, 50% 100%, 0 50%);
}
.page-about .coverage-scope__num {
  font-family: var(--font-display);
  font-size: 34px;
  line-height: 1;
  color: var(--text-dark);
}
.page-about .coverage-scope__title {
  font-family: var(--font-display);
  font-size: 16px;
  margin: 0;
  color: var(--text-dark);
}
.page-about .coverage-scope__text {
  font-size: 13px;
  line-height: 1.7;
  margin: 0;
  color: var(--coverage-ink);
}
.page-about .coverage-scope__chips {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}
.page-about .coverage-scope__chip {
  display: inline-block;
  background: var(--bg-deep);
  color: var(--text-light);
  font-size: 12px;
  padding: 5px 10px;
  clip-path: var(--cut-small);
}

/* ===== 分类维度 ===== */
.page-about .coverage-cats {
  background: var(--bg-green);
  padding: 48px 0;
}
.page-about .coverage-cats__layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: 30px;
}
.page-about .coverage-cats__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
}
.page-about .coverage-cats__cat {
  background: var(--card-warm);
  clip-path: var(--cut-corner);
  padding: 22px;
  display: flex;
  flex-direction: column;
  gap: 16px;
  transition: background var(--ease), transform var(--ease);
}
.page-about .coverage-cats__cat:hover {
  background: var(--card-orange);
  transform: translateY(-2px);
}
.page-about .coverage-cats__header {
  display: flex;
  align-items: center;
  gap: 16px;
}
.page-about .coverage-cats__count {
  font-family: var(--font-display);
  font-size: 36px;
  line-height: 1;
  color: var(--accent-coral);
}
.page-about .coverage-cats__heading {
  display: flex;
  flex-direction: column;
  gap: 4px;
}
.page-about .coverage-cats__name {
  font-family: var(--font-display);
  font-size: 20px;
  margin: 0;
  color: var(--text-dark);
}
.page-about .coverage-cats__label {
  align-self: flex-start;
  font-size: 11px;
  background: var(--bg-deep);
  color: var(--text-light);
  padding: 3px 8px;
  clip-path: var(--cut-small);
}
.page-about .coverage-cats__subs {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 8px;
}
.page-about .coverage-cats__sub {
  background: var(--bg-deep);
  color: var(--text-light);
  font-size: 13px;
  padding: 9px 12px;
  clip-path: var(--cut-small);
  display: flex;
  align-items: center;
  gap: 8px;
  transition: background var(--ease);
}
.page-about .coverage-cats__sub::before {
  content: "";
  width: 7px;
  height: 7px;
  background: var(--accent-yellow);
  display: block;
  flex-shrink: 0;
  clip-path: polygon(50% 0, 100% 50%, 50% 100%, 0 50%);
}
.page-about .coverage-cats__sub:hover {
  background: #233647;
}
.page-about .coverage-cats__figure {
  margin: 0;
  background: rgba(255, 255, 255, 0.08);
  clip-path: var(--cut-corner);
  padding: 10px;
  align-self: center;
}
.page-about .coverage-cats__img {
  width: 100%;
  height: auto;
  display: block;
  aspect-ratio: 5 / 4;
  object-fit: cover;
}
.page-about .coverage-cats__footer {
  display: flex;
  flex-direction: column;
  gap: 16px;
  margin-top: 28px;
  align-items: flex-start;
}
.page-about .coverage-cats__note {
  font-size: 14px;
  color: var(--text-light);
  margin: 0;
}
.page-about .coverage-cats__link {
  display: inline-block;
}

/* ===== 标签体系 ===== */
.page-about .coverage-tags {
  background: var(--bg-deep);
  padding: 48px 0;
}
.page-about .coverage-tags__tree {
  display: grid;
  grid-template-columns: 1fr;
  gap: 12px;
  max-width: 860px;
}
.page-about .coverage-tags__branch {
  background: var(--card-warm);
  clip-path: var(--cut-corner);
  transition: box-shadow var(--ease);
}
.page-about .coverage-tags__branch:hover {
  box-shadow: 0 6px 16px var(--shadow-main);
}
.page-about .coverage-tags__summary {
  list-style: none;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 16px 20px;
  cursor: pointer;
  font-family: var(--font-display);
  font-size: 17px;
  color: var(--text-dark);
}
.page-about .coverage-tags__summary::-webkit-details-marker {
  display: none;
}
.page-about .coverage-tags__summary::after {
  content: "+";
  font-size: 22px;
  line-height: 1;
  color: var(--accent-coral);
  transition: transform var(--ease);
}
.page-about .coverage-tags__branch[open] .coverage-tags__summary::after {
  transform: rotate(45deg);
}
.page-about .coverage-tags__dimension {
  font-family: var(--font-display);
}
.page-about .coverage-tags__meta {
  font-size: 12px;
  color: var(--coverage-ink);
  font-weight: normal;
  font-family: var(--font-body);
}
.page-about .coverage-tags__list {
  list-style: none;
  margin: 0;
  padding: 4px 20px 18px;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}
.page-about .coverage-tags__item {
  display: inline-block;
  background: var(--bg-deep);
  color: var(--text-light);
  font-size: 13px;
  padding: 6px 12px;
  clip-path: var(--cut-small);
  transition: background var(--ease), color var(--ease);
}
.page-about .coverage-tags__item:hover {
  background: var(--accent-yellow);
  color: var(--text-dark);
}
.page-about .coverage-tags__item--hot {
  background: var(--status-hot);
}
.page-about .coverage-tags__item--updated {
  background: var(--status-updated);
}
.page-about .coverage-tags__item--expired {
  background: var(--status-expired);
  color: var(--text-dark);
}
.page-about .coverage-tags__routes {
  margin-top: 26px;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  align-items: center;
}
.page-about .coverage-tags__routes-label {
  font-family: var(--font-display);
  font-size: 14px;
  color: var(--accent-yellow);
  margin-right: 4px;
}
.page-about .coverage-tags__route {
  display: inline-block;
  background: rgba(255, 255, 255, 0.08);
  color: var(--text-light);
  font-size: 13px;
  padding: 7px 12px;
  clip-path: var(--cut-small);
  text-decoration: none;
  transition: background var(--ease), color var(--ease);
}
.page-about .coverage-tags__route:hover {
  background: var(--accent-yellow);
  color: var(--text-dark);
}

/* ===== 更新机制 ===== */
.page-about .coverage-updates {
  background: var(--bg-green);
  padding: 48px 0;
}
.page-about .coverage-updates__timeline {
  position: relative;
  display: grid;
  grid-template-columns: 1fr;
  gap: 22px;
  padding-left: 30px;
  border-left: 3px solid var(--coverage-line);
  margin-left: 14px;
  max-width: 720px;
}
.page-about .coverage-updates__node {
  position: relative;
}
.page-about .coverage-updates__node::before {
  content: "";
  position: absolute;
  left: -37px;
  top: 6px;
  width: 12px;
  height: 12px;
  background: var(--accent-yellow);
  transform: rotate(45deg);
}
.page-about .coverage-updates__node:nth-child(even)::before {
  background: var(--accent-coral);
}
.page-about .coverage-updates__badge {
  display: inline-block;
  background: var(--accent-yellow);
  color: var(--text-dark);
  font-family: var(--font-display);
  font-size: 12px;
  padding: 4px 10px;
  clip-path: var(--cut-small);
  margin-bottom: 8px;
}
.page-about .coverage-updates__node:nth-child(even) .coverage-updates__badge {
  background: var(--accent-coral);
  color: var(--text-light);
}
.page-about .coverage-updates__text {
  font-size: 14px;
  line-height: 1.7;
  margin: 0;
  max-width: 52em;
  color: var(--text-light);
}
.page-about .coverage-updates__link {
  margin-top: 28px;
  display: inline-block;
}

/* ===== 终端适配 ===== */
.page-about .coverage-devices {
  background: var(--bg-deep);
  padding: 48px 0;
}
.page-about .coverage-devices__layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: 30px;
}
.page-about .coverage-devices__switch {
  position: relative;
}
.page-about .coverage-devices__radio {
  position: absolute;
  opacity: 0;
  pointer-events: none;
}
.page-about .coverage-devices__tabs {
  display: flex;
  gap: 6px;
  margin-bottom: 14px;
  flex-wrap: wrap;
}
.page-about .coverage-devices__tab {
  display: inline-block;
  background: rgba(255, 255, 255, 0.1);
  color: var(--text-light);
  font-family: var(--font-display);
  font-size: 14px;
  padding: 9px 18px;
  cursor: pointer;
  clip-path: var(--cut-small);
  transition: background var(--ease), color var(--ease);
}
.page-about .coverage-devices__tab:hover {
  background: rgba(255, 255, 255, 0.2);
}
.page-about .coverage-devices__radio--phone:checked ~ .coverage-devices__tabs .coverage-devices__tab--phone,
.page-about .coverage-devices__radio--tablet:checked ~ .coverage-devices__tabs .coverage-devices__tab--tablet,
.page-about .coverage-devices__radio--desktop:checked ~ .coverage-devices__tabs .coverage-devices__tab--desktop {
  background: var(--accent-yellow);
  color: var(--text-dark);
}
.page-about .coverage-devices__panels {
  background: var(--card-warm);
  clip-path: var(--cut-corner);
  min-height: 210px;
}
.page-about .coverage-devices__panel {
  display: none;
  padding: 22px;
}
.page-about .coverage-devices__radio--phone:checked ~ .coverage-devices__panels .coverage-devices__panel--phone,
.page-about .coverage-devices__radio--tablet:checked ~ .coverage-devices__panels .coverage-devices__panel--tablet,
.page-about .coverage-devices__radio--desktop:checked ~ .coverage-devices__panels .coverage-devices__panel--desktop {
  display: block;
}
.page-about .coverage-devices__device {
  display: inline-block;
  font-family: var(--font-display);
  font-size: 20px;
  background: var(--accent-coral);
  color: var(--text-light);
  padding: 4px 12px;
  clip-path: var(--cut-small);
  margin-bottom: 14px;
}
.page-about .coverage-devices__info {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 10px 16px;
  margin: 0;
  font-size: 14px;
}
.page-about .coverage-devices__info dt {
  font-weight: 700;
  color: var(--text-dark);
}
.page-about .coverage-devices__info dd {
  margin: 0;
  color: var(--coverage-ink);
}
.page-about .coverage-devices__table-wrap {
  margin-top: 14px;
  overflow-x: auto;
}
.page-about .coverage-devices__table {
  width: 100%;
  min-width: 560px;
  border-collapse: collapse;
  background: var(--card-orange);
  font-size: 13px;
}
.page-about .coverage-devices__table th,
.page-about .coverage-devices__table td {
  text-align: left;
  padding: 10px 12px;
  border-bottom: 1px solid rgba(17, 17, 17, 0.12);
  color: var(--text-dark);
}
.page-about .coverage-devices__table th {
  background: var(--bg-deep);
  color: var(--text-light);
  font-family: var(--font-display);
  font-size: 12px;
  letter-spacing: 0.03em;
}
.page-about .coverage-devices__table tbody tr:hover {
  background: var(--accent-yellow);
}
.page-about .coverage-devices__figure {
  margin: 0;
  background: rgba(255, 255, 255, 0.08);
  clip-path: var(--cut-corner);
  padding: 10px;
  align-self: center;
}
.page-about .coverage-devices__img {
  width: 100%;
  height: auto;
  display: block;
  aspect-ratio: 4 / 3;
  object-fit: cover;
}
.page-about .coverage-devices__link {
  margin-top: 28px;
  display: inline-block;
}

/* ===== 响应式 ===== */
@media (min-width: 768px) {
  .page-about .coverage-hero__stats {
    grid-template-columns: repeat(3, 1fr);
  }
  .page-about .coverage-scope__grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .page-about .coverage-cats__grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .page-about .coverage-cats__subs {
    grid-template-columns: 1fr 1fr;
  }
  .page-about .coverage-tags__tree {
    grid-template-columns: 1fr 1fr;
    max-width: none;
  }
  .page-about .coverage-tags__routes {
    flex-wrap: nowrap;
  }
  .page-about .coverage-devices__panels {
    min-height: 230px;
  }
}

@media (min-width: 992px) {
  .page-about .coverage-hero {
    padding: 40px 0 64px;
  }
  .page-about .coverage-hero__grid {
    grid-template-columns: 1.08fr 0.92fr;
    align-items: center;
  }
  .page-about .coverage-hero__title {
    font-size: 44px;
  }
  .page-about .coverage-scope__grid {
    grid-template-columns: repeat(4, 1fr);
    gap: 16px;
  }
  .page-about .coverage-cats__layout {
    grid-template-columns: 1fr 0.72fr;
    align-items: start;
  }
  .page-about .coverage-cats__grid {
    gap: 16px;
  }
  .page-about .coverage-devices__layout {
    grid-template-columns: 1.2fr 0.8fr;
    align-items: start;
  }
  .page-about .coverage-devices__panels {
    min-height: 250px;
  }
}