/* ========== 页面专属：收录范围 .page-about ========== */
.page-about {
  --about-shadow-lg: 0 14px 34px rgba(52, 73, 94, 0.16);
  --about-shadow-deep: 0 20px 46px rgba(52, 73, 94, 0.22);
  --about-round-lg: 14px;
  --about-ink-soft: #52616f;
}

/* ---------- Hero ---------- */
.page-about .coverage-hero {
  padding: 24px 0 30px;
}
.page-about .coverage-hero__inner {
  margin-top: 22px;
  display: flex;
  flex-direction: column;
  gap: 20px;
}
.page-about .coverage-hero__kicker {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 2px;
  color: var(--c-orange);
  text-transform: uppercase;
  margin: 0 0 6px;
}
.page-about .coverage-hero h1 {
  font-family: var(--font-head);
  font-size: 1.75rem;
  line-height: 1.2;
  color: var(--c-ink);
  margin: 0 0 12px;
}
.page-about .coverage-hero__lead {
  font-family: var(--font-body);
  font-size: 15px;
  line-height: 1.75;
  color: var(--c-ink);
  max-width: 780px;
  margin: 0;
}
.page-about .coverage-hero__vol {
  flex: 0 0 auto;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  width: 118px;
  height: 118px;
  background: linear-gradient(135deg, var(--c-orange), #f39a68);
  color: #fff;
  border-radius: 6px 20px 6px 20px;
  box-shadow: var(--about-shadow-deep);
  transform: rotate(2deg);
  margin-left: auto;
}
.page-about .coverage-hero__vol-top {
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 3px;
}
.page-about .coverage-hero__vol-num {
  font-family: var(--font-mono);
  font-size: 40px;
  font-weight: 800;
  line-height: 1.1;
}
.page-about .coverage-hero__vol-bottom {
  font-family: var(--font-head);
  font-size: 12px;
  font-weight: 700;
}

/* ---------- 01 收录概览 ---------- */
.page-about .sec-about-overview {
  padding: 40px 0 46px;
}
.page-about .sec-about-overview .section-head {
  margin-bottom: 24px;
}
.page-about .stat-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 14px;
  margin-bottom: 36px;
}
.page-about .stat-card {
  position: relative;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  gap: 14px;
  min-height: 122px;
  padding: 18px 16px;
  border-radius: var(--radius-md);
  color: #fff;
  box-shadow: var(--shadow-sm);
  overflow: hidden;
}
.page-about .stat-card::before {
  content: "";
  position: absolute;
  top: 12px;
  right: 14px;
  width: 26px;
  height: 5px;
  background: rgba(255, 255, 255, 0.3);
  border-radius: 3px;
  transform: rotate(-45deg);
}
.page-about .stat-card::after {
  content: "";
  position: absolute;
  right: -24px;
  bottom: -24px;
  width: 80px;
  height: 80px;
  background: rgba(255, 255, 255, 0.12);
  border-radius: 50%;
}
.page-about .stat-card:last-child {
  grid-column: span 2;
}
.page-about .stat-card--ink { background: var(--c-ink); }
.page-about .stat-card--orange { background: var(--c-orange); }
.page-about .stat-card--blue { background: var(--c-blue); }
.page-about .stat-card--green { background: var(--c-green-deep); }
.page-about .stat-card--purple { background: var(--c-purple); }
.page-about .stat-card__num {
  position: relative;
  z-index: 1;
  display: flex;
  align-items: baseline;
  gap: 4px;
  font-family: var(--font-mono);
  font-size: 30px;
  font-weight: 800;
  line-height: 1;
}
.page-about .stat-card__unit {
  font-family: var(--font-head);
  font-size: 13px;
  font-weight: 400;
  opacity: 0.8;
}
.page-about .stat-card__desc {
  position: relative;
  z-index: 1;
  font-family: var(--font-head);
  font-size: 12px;
  font-weight: 700;
  line-height: 1.4;
  opacity: 0.88;
}

.page-about .overview-split {
  display: grid;
  grid-template-columns: 1fr;
  gap: 24px;
}
.page-about .overview-split__img {
  width: 100%;
  max-width: 300px;
  height: auto;
  border-radius: var(--radius-md);
  object-fit: cover;
  aspect-ratio: 3 / 4;
  box-shadow: var(--about-shadow-lg);
}
.page-about .overview-split__body h3 {
  font-family: var(--font-head);
  font-size: 18px;
  font-weight: 700;
  color: var(--c-ink);
  margin: 0 0 10px;
}
.page-about .overview-split__body > p {
  font-family: var(--font-body);
  font-size: 14px;
  line-height: 1.7;
  color: var(--c-ink);
  margin: 0 0 18px;
}
.page-about .overview-bars {
  display: grid;
  gap: 12px;
  margin-bottom: 14px;
}
.page-about .overview-bars .metric-bar {
  display: grid;
  grid-template-columns: 88px 1fr 50px;
  align-items: center;
  gap: 8px;
}
.page-about .overview-bars .metric-bar__label {
  font-family: var(--font-head);
  font-size: 13px;
  font-weight: 700;
  color: var(--c-ink);
}
.page-about .overview-bars .metric-bar__track {
  height: 8px;
  background: var(--c-line);
  border-radius: 40px;
  overflow: hidden;
}
.page-about .overview-bars .metric-bar__fill {
  display: block;
  height: 100%;
  border-radius: 40px;
}
.page-about .overview-bars .metric-bar__value {
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 700;
  color: var(--c-ink);
  text-align: right;
}
.page-about .page-about__fill-blue {
  background: var(--c-blue);
}
.page-about .overview-bars__note {
  font-family: var(--font-body);
  font-size: 13px;
  line-height: 1.6;
  color: var(--about-ink-soft);
  margin: 0;
}

/* ---------- 02 分类体系 ---------- */
.page-about .sec-about-taxo {
  padding: 44px 0 48px;
}
.page-about .sec-about-taxo .section-head {
  margin-bottom: 26px;
}
.page-about .taxo-hero {
  display: grid;
  grid-template-columns: 1fr;
  gap: 22px;
  margin-bottom: 34px;
}
.page-about .taxo-hero__img img {
  width: 100%;
  max-width: 600px;
  height: auto;
  border-radius: var(--radius-md);
  object-fit: cover;
  aspect-ratio: 3 / 2;
  box-shadow: var(--about-shadow-deep);
}
.page-about .taxo-hero__note {
  display: flex;
  flex-direction: column;
  gap: 18px;
}
.page-about .taxo-hero__note p {
  font-family: var(--font-body);
  font-size: 14px;
  line-height: 1.75;
  color: rgba(255, 255, 255, 0.88);
  margin: 0;
}
.page-about .taxo-hero__tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.page-about .cat-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
}
.page-about .cat-node {
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid rgba(255, 255, 255, 0.14);
  border-radius: var(--radius-md);
  overflow: hidden;
  transition: background 0.2s var(--ease);
}
.page-about .cat-node:hover {
  background: rgba(255, 255, 255, 0.1);
}
.page-about .cat-node summary {
  list-style: none;
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 14px 16px;
  cursor: pointer;
  user-select: none;
  border-left: 4px solid transparent;
}
.page-about .cat-node summary::-webkit-details-marker {
  display: none;
}
.page-about .cat-node summary::after {
  content: "+";
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 16px;
  font-weight: 700;
  color: rgba(255, 255, 255, 0.5);
}
.page-about .cat-node[open] summary::after {
  content: "−";
}
.page-about .cat-node[open] summary {
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}
.page-about .cat-node--orange summary { border-left-color: var(--c-orange); }
.page-about .cat-node--green summary { border-left-color: var(--c-green); }
.page-about .cat-node--yellow summary { border-left-color: var(--c-yellow); }
.page-about .cat-node--blue summary { border-left-color: var(--c-blue); }
.page-about .cat-node--purple summary { border-left-color: var(--c-purple); }
.page-about .cat-node--teal summary { border-left-color: var(--c-teal); }
.page-about .cat-node--white summary { border-left-color: #ecf0f1; }
.page-about .cat-node--red summary { border-left-color: var(--c-red); }
.page-about .cat-node__no {
  font-family: var(--font-mono);
  font-size: 14px;
  font-weight: 800;
  color: var(--c-orange);
  width: 28px;
  flex-shrink: 0;
}
.page-about .cat-node__name {
  font-family: var(--font-head);
  font-size: 16px;
  font-weight: 700;
  color: #fff;
  flex: 1;
}
.page-about .cat-node__count {
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 700;
  color: #fff;
  background: rgba(255, 107, 53, 0.75);
  border-radius: 30px;
  padding: 4px 10px;
}
.page-about .cat-node__tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  padding: 14px 16px;
  animation: pageAboutReveal 0.24s var(--ease);
}
.page-about .cat-tag {
  display: inline-block;
  font-family: var(--font-head);
  font-size: 12px;
  line-height: 1;
  padding: 6px 10px;
  border-radius: 4px;
  color: rgba(255, 255, 255, 0.9);
  background: rgba(255, 255, 255, 0.08);
  border: 1px solid rgba(255, 255, 255, 0.14);
}
.page-about .cat-tag--orange { background: rgba(255, 107, 53, 0.22); border-color: rgba(255, 107, 53, 0.42); }
.page-about .cat-tag--green { background: rgba(46, 204, 113, 0.18); border-color: rgba(46, 204, 113, 0.42); }
.page-about .cat-tag--yellow { background: rgba(241, 196, 15, 0.16); border-color: rgba(241, 196, 15, 0.42); }
.page-about .cat-tag--blue { background: rgba(52, 152, 219, 0.2); border-color: rgba(52, 152, 219, 0.42); }
.page-about .cat-tag--purple { background: rgba(155, 89, 182, 0.2); border-color: rgba(155, 89, 182, 0.42); }
.page-about .cat-tag--teal { background: rgba(26, 188, 156, 0.2); border-color: rgba(26, 188, 156, 0.42); }
.page-about .cat-tag--white { background: rgba(255, 255, 255, 0.16); border-color: rgba(255, 255, 255, 0.4); }
.page-about .cat-tag--red { background: rgba(231, 76, 60, 0.2); border-color: rgba(231, 76, 60, 0.42); }

@keyframes pageAboutReveal {
  from { opacity: 0; transform: translateY(-4px); }
  to { opacity: 1; transform: translateY(0); }
}

/* ---------- 03 更新机制 ---------- */
.page-about .sec-about-update {
  padding: 44px 0 48px;
}
.page-about .sec-about-update .section-head {
  margin-bottom: 28px;
}
.page-about .update-steps {
  list-style: none;
  margin: 0 0 28px;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
}
.page-about .update-step {
  position: relative;
  padding: 20px 18px 18px 58px;
  background: #fff;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
  border-left: 4px solid var(--c-orange);
}
.page-about .update-step:nth-child(2) { border-left-color: var(--c-green); }
.page-about .update-step:nth-child(3) { border-left-color: var(--c-blue); }
.page-about .update-step:nth-child(4) { border-left-color: var(--c-purple); }
.page-about .update-step__no {
  position: absolute;
  left: 18px;
  top: 18px;
  font-family: var(--font-mono);
  font-size: 20px;
  font-weight: 800;
  color: var(--c-orange);
}
.page-about .update-step:nth-child(2) .update-step__no { color: var(--c-green); }
.page-about .update-step:nth-child(3) .update-step__no { color: var(--c-blue); }
.page-about .update-step:nth-child(4) .update-step__no { color: var(--c-purple); }
.page-about .update-step h3 {
  font-family: var(--font-head);
  font-size: 16px;
  font-weight: 700;
  color: var(--c-ink);
  margin: 0 0 6px;
}
.page-about .update-step p {
  font-family: var(--font-body);
  font-size: 13px;
  line-height: 1.65;
  color: var(--about-ink-soft);
  margin: 0;
}
.page-about .update-meta {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 14px;
  background: var(--c-ink);
  border-radius: var(--radius-md);
  padding: 22px 20px;
}
.page-about .update-meta__item {
  display: flex;
  flex-direction: column;
  gap: 6px;
}
.page-about .update-meta__label {
  font-family: var(--font-head);
  font-size: 12px;
  color: rgba(255, 255, 255, 0.62);
}
.page-about .update-meta__value {
  font-family: var(--font-mono);
  font-size: 16px;
  font-weight: 800;
  color: #fff;
  letter-spacing: 0.4px;
}

/* ---------- 04 检索与筛选 ---------- */
.page-about .sec-about-search {
  padding: 44px 0 48px;
}
.page-about .sec-about-search .section-head {
  margin-bottom: 28px;
}
.page-about .search-cards {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
  margin-bottom: 28px;
}
.page-about .search-card {
  background: #fff;
  border-radius: var(--radius-md);
  padding: 22px 20px;
  box-shadow: var(--shadow-sm);
  border-top: 4px solid var(--c-line);
}
.page-about .search-card--orange { border-top-color: var(--c-orange); }
.page-about .search-card--green { border-top-color: var(--c-green); }
.page-about .search-card--blue { border-top-color: var(--c-blue); }
.page-about .search-card--purple { border-top-color: var(--c-purple); }
.page-about .search-card__glyph {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: 8px;
  font-family: var(--font-mono);
  font-size: 18px;
  font-weight: 800;
  color: #fff;
  margin-bottom: 12px;
}
.page-about .search-card--orange .search-card__glyph { background: var(--c-orange); }
.page-about .search-card--green .search-card__glyph { background: var(--c-green-deep); }
.page-about .search-card--blue .search-card__glyph { background: var(--c-blue); }
.page-about .search-card--purple .search-card__glyph { background: var(--c-purple); }
.page-about .search-card h3 {
  font-family: var(--font-head);
  font-size: 16px;
  font-weight: 700;
  color: var(--c-ink);
  margin: 0 0 8px;
}
.page-about .search-card p {
  font-family: var(--font-body);
  font-size: 13px;
  line-height: 1.7;
  color: var(--about-ink-soft);
  margin: 0;
}
.page-about .search-bar {
  display: flex;
  flex-direction: column;
  gap: 14px;
  align-items: flex-start;
  background: #fff;
  border-radius: var(--radius-md);
  padding: 18px 20px;
  box-shadow: var(--shadow-sm);
}
.page-about .search-bar__text {
  font-family: var(--font-body);
  font-size: 14px;
  line-height: 1.65;
  color: var(--c-ink);
  margin: 0;
}

/* ---------- 05 内容中心 ---------- */
.page-about .sec-about-center {
  padding: 44px 0 48px;
}
.page-about .sec-about-center .section-head {
  margin-bottom: 28px;
}
.page-about .center-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 28px;
}
.page-about .center-grid__main h3 {
  font-family: var(--font-head);
  font-size: 18px;
  font-weight: 700;
  color: #fff;
  margin: 0 0 16px;
}
.page-about .service-list {
  list-style: none;
  margin: 0 0 24px;
  padding: 0;
  display: grid;
  gap: 12px;
}
.page-about .service-list__item {
  display: flex;
  gap: 14px;
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: var(--radius-md);
  padding: 18px 16px;
}
.page-about .service-list__no {
  font-family: var(--font-mono);
  font-size: 18px;
  font-weight: 800;
  color: var(--c-orange);
  width: 34px;
  flex-shrink: 0;
}
.page-about .service-list__body h4 {
  font-family: var(--font-head);
  font-size: 15px;
  font-weight: 700;
  color: #fff;
  margin: 0 0 6px;
}
.page-about .service-list__body p {
  font-family: var(--font-body);
  font-size: 13px;
  line-height: 1.65;
  color: rgba(255, 255, 255, 0.78);
  margin: 0;
}
.page-about .center-grid__side {
  display: flex;
  flex-direction: column;
  gap: 20px;
}
.page-about .center-grid__img {
  width: 100%;
  max-width: 400px;
  height: auto;
  border-radius: var(--radius-md);
  object-fit: cover;
  aspect-ratio: 4 / 3;
  box-shadow: var(--about-shadow-deep);
}
.page-about .price-card {
  background: #fff;
  border-radius: var(--radius-md);
  padding: 22px 20px;
  box-shadow: var(--about-shadow-lg);
}
.page-about .price-card h3 {
  font-family: var(--font-head);
  font-size: 17px;
  font-weight: 700;
  color: var(--c-ink);
  margin: 0 0 14px;
  padding-bottom: 12px;
  border-bottom: 3px solid var(--c-yellow);
}
.page-about .price-card__row {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 10px;
  padding: 12px 0;
  border-bottom: 1px dashed var(--c-line);
}
.page-about .price-card__name {
  font-family: var(--font-head);
  font-size: 14px;
  font-weight: 700;
  color: var(--c-ink);
}
.page-about .price-card__num {
  font-family: var(--font-mono);
  font-size: 26px;
  font-weight: 800;
  color: var(--c-orange);
  line-height: 1;
}
.page-about .price-card__unit {
  font-family: var(--font-mono);
  font-size: 11px;
  color: #7f8c99;
}
.page-about .price-card__free {
  font-family: var(--font-mono);
  font-size: 20px;
  font-weight: 800;
  color: var(--c-green-deep);
  line-height: 1;
}
.page-about .price-card__foot {
  font-family: var(--font-body);
  font-size: 13px;
  line-height: 1.6;
  color: var(--about-ink-soft);
  margin: 16px 0 0;
}
.page-about .center-cta {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-top: 30px;
}

/* ---------- 平板与桌面 ---------- */
@media (min-width: 768px) {
  .page-about .coverage-hero {
    padding: 30px 0 36px;
  }
  .page-about .coverage-hero__inner {
    flex-direction: row;
    align-items: flex-end;
    justify-content: space-between;
    gap: 32px;
  }
  .page-about .coverage-hero h1 {
    font-size: 2.2rem;
  }

  .page-about .stat-grid {
    grid-template-columns: repeat(3, 1fr);
  }
  .page-about .stat-card:last-child {
    grid-column: auto;
  }

  .page-about .overview-split {
    grid-template-columns: 300px 1fr;
    gap: 32px;
  }

  .page-about .cat-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 16px;
  }

  .page-about .update-meta {
    grid-template-columns: repeat(4, 1fr);
  }

  .page-about .search-cards {
    grid-template-columns: repeat(2, 1fr);
  }

  .page-about .center-grid {
    grid-template-columns: 1fr;
  }
}

@media (min-width: 900px) {
  .page-about .taxo-hero {
    grid-template-columns: 600px 1fr;
    align-items: start;
  }
  .page-about .update-steps {
    grid-template-columns: repeat(4, 1fr);
    gap: 16px;
  }
  .page-about .update-step {
    padding: 24px 18px 18px;
    border-left: 0;
    border-top: 4px solid var(--c-orange);
  }
  .page-about .update-step:nth-child(2) { border-top-color: var(--c-green); }
  .page-about .update-step:nth-child(3) { border-top-color: var(--c-blue); }
  .page-about .update-step:nth-child(4) { border-top-color: var(--c-purple); }
  .page-about .update-step__no {
    position: static;
    display: block;
    font-size: 24px;
    margin-bottom: 10px;
  }
  .page-about .search-cards {
    grid-template-columns: repeat(4, 1fr);
  }
  .page-about .search-bar {
    flex-direction: row;
    justify-content: space-between;
    align-items: center;
  }
}

@media (min-width: 1024px) {
  .page-about .stat-grid {
    grid-template-columns: repeat(5, 1fr);
  }
  .page-about .center-grid {
    grid-template-columns: 1fr 380px;
    gap: 40px;
  }
}