.page-about {
  --about-teal: #1ABC9C;
  --about-teal-deep: #0E8C7F;
  --about-deep: #233240;
  --about-deep2: #1B2A38;
  --about-orange: #E67E22;
  --about-amber: #F39C12;
  --about-card-bg: #F5F5F5;
  --about-card-border: #F1C40F;
  --about-text-light: #ECF0F1;
  --about-text-dark: #2C3E50;
}

/* ===== Hero ===== */
.page-about .about-hero {
  background:
    linear-gradient(135deg, rgba(30, 50, 70, 0.92) 0%, rgba(35, 50, 64, 0.96) 60%, rgba(44, 62, 80, 1) 100%),
    repeating-linear-gradient(45deg, rgba(241, 196, 15, 0.18) 0 2px, transparent 2px 14px);
  border-bottom: 1px solid rgba(241, 196, 15, 0.5);
  padding: 40px 0 48px;
  color: var(--about-text-light);
}

.page-about .about-hero .breadcrumb {
  margin-bottom: 32px;
  font-size: 13px;
  color: var(--text-muted);
}

.page-about .about-hero .breadcrumb a {
  color: var(--text-muted);
  text-decoration: none;
  transition: color 0.2s;
}

.page-about .about-hero .breadcrumb a:hover {
  color: var(--border-card);
}

.page-about .breadcrumb-sep {
  margin: 0 8px;
  color: rgba(189, 195, 199, 0.55);
}

.page-about .about-hero-kicker {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.16em;
  color: var(--border-card);
  margin-bottom: 14px;
  text-transform: uppercase;
}

.page-about .about-hero-kicker::before {
  content: "";
  width: 28px;
  height: 4px;
  background: var(--border-card);
  clip-path: polygon(0 0, 100% 0, 80% 100%, 0 100%);
  display: inline-block;
}

.page-about .about-hero-cols {
  display: grid;
  gap: 36px;
}

.page-about .about-hero h1 {
  font-family: var(--font-head);
  font-size: 30px;
  font-weight: 800;
  line-height: 1.3;
  color: var(--about-text-light);
  margin: 0 0 18px;
  letter-spacing: 0.02em;
}

.page-about .about-hero-lead {
  font-size: 16px;
  line-height: 1.8;
  color: rgba(236, 240, 241, 0.85);
  margin: 0 0 22px;
  max-width: 60ch;
}

.page-about .about-hero-tags {
  flex-wrap: wrap;
  gap: 10px;
}

.page-about .about-hero-tags .tag {
  font-size: 13px;
  padding: 6px 12px;
}

.page-about .about-hero-facts {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 14px;
}

.page-about .about-hero-fact {
  background: rgba(255, 255, 255, 0.07);
  border: 1px solid rgba(241, 196, 15, 0.35);
  border-left: 4px solid var(--border-card);
  padding: 18px 16px;
  clip-path: polygon(0 0, calc(100% - 12px) 0, 100% 12px, 100% 100%, 12px 100%, 0 calc(100% - 12px));
}

.page-about .about-hero-num {
  display: block;
  font-family: var(--font-head);
  font-size: 32px;
  font-weight: 800;
  color: var(--border-card);
  line-height: 1;
  margin-bottom: 6px;
}

.page-about .about-hero-num-version {
  font-size: 26px;
}

.page-about .about-hero-label {
  font-size: 13px;
  color: var(--text-muted);
}

/* ===== 通用Section头部 ===== */
.page-about .about-section-head {
  margin-bottom: 32px;
  display: flex;
  align-items: flex-start;
  gap: 18px;
}

.page-about .about-section-head .seq-marker {
  flex-shrink: 0;
  font-size: 34px;
  line-height: 1;
  font-weight: 800;
  color: var(--border-card);
}

.page-about .about-section-head h2 {
  font-family: var(--font-head);
  font-size: 26px;
  font-weight: 800;
  margin: 0 0 6px;
  color: var(--text-main);
}

.page-about .about-section-head .section-note {
  font-size: 14px;
  color: var(--text-muted);
  margin: 0;
}

.page-about .about-section-head-light h2 {
  color: var(--about-text-light);
}

.page-about .about-section-head-light .section-note {
  color: rgba(236, 240, 241, 0.7);
}

/* ===== 收录概况 ===== */
.page-about .about-coverage {
  background:
    linear-gradient(180deg, var(--about-deep2) 0%, var(--bg-primary) 100%);
  position: relative;
}

.page-about .about-coverage::before {
  content: "";
  position: absolute;
  top: 0;
  right: 0;
  width: 120px;
  height: 120px;
  background: repeating-linear-gradient(45deg, rgba(241, 196, 15, 0.12) 0 2px, transparent 2px 12px);
  clip-path: polygon(0 0, 100% 0, 100% 100%);
  pointer-events: none;
}

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

.page-about .about-coverage-card {
  background: var(--about-card-bg);
  border: 1px solid var(--about-card-border);
  border-left: 6px solid var(--about-card-border);
  padding: 22px 16px 20px;
  clip-path: polygon(0 0, calc(100% - 14px) 0, 100% 14px, 100% 100%, 14px 100%, 0 calc(100% - 14px));
  box-shadow: var(--shadow-soft);
  transition: transform 0.3s var(--ease-out), box-shadow 0.3s;
}

.page-about .about-coverage-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lift);
}

.page-about .about-coverage-card-total {
  background: linear-gradient(135deg, var(--about-orange), #F39C12);
  border-color: #F39C12;
  border-left-color: #fff;
}

.page-about .about-coverage-card-total .about-coverage-glyph,
.page-about .about-coverage-card-total .about-coverage-num,
.page-about .about-coverage-card-total .about-coverage-label,
.page-about .about-coverage-card-total .about-coverage-sub {
  color: #fff;
}

.page-about .about-coverage-glyph {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  font-size: 16px;
  font-weight: 800;
  background: var(--tag-genre);
  color: #fff;
  margin-bottom: 14px;
  clip-path: polygon(0 0, calc(100% - 8px) 0, 100% 8px, 100% 100%, 8px 100%, 0 calc(100% - 8px));
}

.page-about .about-coverage-num {
  font-family: var(--font-head);
  font-size: 32px;
  font-weight: 800;
  color: var(--about-text-dark);
  line-height: 1;
  margin-bottom: 6px;
}

.page-about .about-coverage-label {
  font-size: 15px;
  font-weight: 700;
  color: var(--about-text-dark);
  margin-bottom: 4px;
}

.page-about .about-coverage-sub {
  font-size: 13px;
  color: var(--text-muted-on-light);
  line-height: 1.5;
}

/* ===== 分类体系 ===== */
.page-about .about-taxonomy {
  background:
    radial-gradient(circle at 15% 20%, rgba(255, 255, 255, 0.25) 0%, transparent 40%),
    linear-gradient(160deg, var(--about-teal) 0%, #148F77 100%);
  position: relative;
  overflow: hidden;
}

.page-about .about-taxonomy::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  width: 100%;
  height: 40px;
  background: repeating-linear-gradient(-45deg, rgba(255, 255, 255, 0.08) 0 2px, transparent 2px 12px);
  pointer-events: none;
}

.page-about .about-taxo-wrap {
  display: grid;
  gap: 28px;
}

.page-about .about-taxo-main {
  display: grid;
  gap: 20px;
}

.page-about .about-taxo-block {
  background: rgba(255, 255, 255, 0.9);
  padding: 20px;
  clip-path: polygon(0 0, calc(100% - 16px) 0, 100% 16px, 100% 100%, 16px 100%, 0 calc(100% - 16px));
  box-shadow: 0 8px 28px rgba(0, 0, 0, 0.18);
}

.page-about .about-taxo-block-head {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 16px;
}

.page-about .about-taxo-rank {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 28px;
  background: var(--about-teal-deep);
  color: #fff;
  font-size: 13px;
  font-weight: 800;
  clip-path: polygon(0 0, calc(100% - 8px) 0, 100% 8px, 100% 100%, 8px 100%, 0 calc(100% - 8px));
}

.page-about .about-taxo-block strong {
  font-family: var(--font-head);
  font-size: 18px;
  color: var(--about-text-dark);
}

.page-about .about-taxo-count-badge {
  margin-left: auto;
  background: var(--border-card);
  color: var(--about-text-dark);
  font-size: 13px;
  font-weight: 700;
  padding: 4px 12px;
  clip-path: polygon(0 0, calc(100% - 6px) 0, 100% 6px, 100% 100%, 6px 100%, 0 calc(100% - 6px));
}

.page-about .about-l1-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 10px;
}

.page-about .about-l1-item {
  --item-color: var(--bg-section-a);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  background: var(--item-color);
  color: #fff;
  padding: 12px 14px;
  clip-path: polygon(0 0, calc(100% - 10px) 0, 100% 10px, 100% 100%, 10px 100%, 0 calc(100% - 10px));
}

.page-about .about-l1-item:nth-child(1) { --item-color: #E67E22; }
.page-about .about-l1-item:nth-child(2) { --item-color: #8E44AD; }
.page-about .about-l1-item:nth-child(3) { --item-color: #3498DB; }
.page-about .about-l1-item:nth-child(4) { --item-color: #1ABC9C; }
.page-about .about-l1-item:nth-child(5) { --item-color: #9B59B6; }
.page-about .about-l1-item:nth-child(6) { --item-color: #E74C3C; }
.page-about .about-l1-item:nth-child(7) { --item-color: #16A085; }
.page-about .about-l1-item:nth-child(8) { --item-color: #7F8C8D; }
.page-about .about-l1-item:nth-child(9) { --item-color: #D35400; }
.page-about .about-l1-item:nth-child(10) { --item-color: #2E86C1; }
.page-about .about-l1-item:nth-child(11) { --item-color: #117A65; }
.page-about .about-l1-item:nth-child(12) { --item-color: #6C3483; }

.page-about .about-l1-name {
  font-size: 14px;
  font-weight: 700;
}

.page-about .about-l1-count {
  font-size: 14px;
  font-weight: 800;
  opacity: 0.35;
}

.page-about .about-taxo-expand-btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: transparent;
  border: 1px dashed var(--tag-genre);
  color: var(--about-teal-deep);
  padding: 10px 16px;
  font-size: 14px;
  font-weight: 700;
  font-family: var(--font-body);
  cursor: pointer;
  clip-path: polygon(0 0, calc(100% - 10px) 0, 100% 10px, 100% 100%, 10px 100%, 0 calc(100% - 10px));
  transition: background 0.2s, color 0.2s;
}

.page-about .about-taxo-expand-btn:hover {
  background: var(--tag-genre);
  color: #fff;
}

.page-about .about-expand-indicator {
  display: inline-block;
  font-size: 18px;
  font-weight: 800;
  line-height: 1;
  transition: transform 0.2s;
}

.page-about .about-taxo-expand-btn[aria-expanded="true"] .about-expand-indicator {
  transform: rotate(45deg);
}

.page-about .about-l2-tags,
.page-about .about-l3-tags {
  gap: 8px;
  margin-top: 12px;
}

.page-about .about-l2-tags .tag,
.page-about .about-l3-tags .tag {
  font-size: 13px;
  padding: 6px 10px;
}

.page-about .about-taxo-figure {
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.page-about .about-taxo-figure img {
  width: 100%;
  height: auto;
  max-width: 400px;
  clip-path: polygon(0 0, calc(100% - 16px) 0, 100% 16px, 100% 100%, 16px 100%, 0 calc(100% - 16px));
  border: 2px solid rgba(255, 255, 255, 0.4);
  box-shadow: var(--shadow-lift);
}

.page-about .about-taxo-figure figcaption,
.page-about .about-update-figure figcaption,
.page-about .about-device-figure figcaption {
  font-size: 13px;
  color: rgba(255, 255, 255, 0.8);
  padding-left: 4px;
}

/* ===== 索引与检索 ===== */
.page-about .about-search {
  background:
    linear-gradient(180deg, var(--bg-primary) 0%, var(--about-deep) 100%);
}

.page-about .about-search-steps {
  display: grid;
  gap: 16px;
}

.page-about .about-step {
  display: grid;
  grid-template-columns: 52px 1fr;
  gap: 16px;
  align-items: start;
  padding: 20px;
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid rgba(241, 196, 15, 0.18);
  border-left: 4px solid var(--border-card);
  clip-path: polygon(0 0, calc(100% - 14px) 0, 100% 14px, 100% 100%, 14px 100%, 0 calc(100% - 14px));
  transition: background 0.3s;
}

.page-about .about-step:hover {
  background: rgba(255, 255, 255, 0.09);
}

.page-about .about-step-num {
  font-family: var(--font-head);
  font-size: 32px;
  font-weight: 800;
  color: var(--border-card);
  line-height: 1;
  margin-top: 4px;
}

.page-about .about-step-content h3 {
  font-family: var(--font-head);
  font-size: 19px;
  font-weight: 700;
  color: var(--about-text-light);
  margin: 0 0 8px;
}

.page-about .about-step-content p {
  font-size: 14px;
  line-height: 1.7;
  color: var(--text-muted);
  margin: 0 0 12px;
}

.page-about .about-step-tags {
  gap: 8px;
  flex-wrap: wrap;
}

.page-about .about-step-tags .tag {
  font-size: 13px;
  padding: 5px 10px;
}

.page-about .about-step-link {
  font-size: 13px;
  padding: 6px 16px;
}

/* ===== 更新与适配 ===== */
.page-about .about-update {
  background:
    radial-gradient(circle at 85% 10%, rgba(241, 196, 15, 0.12) 0%, transparent 45%),
    linear-gradient(150deg, var(--bg-section-b) 0%, #6C3483 100%);
  position: relative;
  overflow: hidden;
}

.page-about .about-update::before {
  content: "";
  position: absolute;
  top: 30px;
  left: 0;
  width: 200px;
  height: 200px;
  background: repeating-linear-gradient(45deg, rgba(255, 255, 255, 0.06) 0 2px, transparent 2px 10px);
  clip-path: polygon(0 0, 100% 0, 0 100%);
  pointer-events: none;
}

.page-about .about-update-grid {
  display: grid;
  gap: 28px;
}

.page-about .about-update-main {
  display: grid;
  gap: 24px;
}

.page-about .about-timeline {
  position: relative;
  display: grid;
  gap: 0;
}

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  left: 9px;
  top: 10px;
  bottom: 10px;
  width: 3px;
  background: linear-gradient(180deg, var(--border-card), rgba(241, 196, 15, 0.25));
}

.page-about .about-timeline-item {
  position: relative;
  padding-left: 34px;
  padding-bottom: 22px;
}

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

.page-about .about-timeline-dot {
  position: absolute;
  left: 0;
  top: 6px;
  width: 20px;
  height: 20px;
  background: var(--border-card);
  border: 3px solid #fff;
  clip-path: polygon(50% 0, 100% 50%, 50% 100%, 0 50%);
  z-index: 1;
}

.page-about .about-timeline-tag {
  display: inline-block;
  background: var(--status-new);
  color: #fff;
  font-size: 12px;
  font-weight: 700;
  padding: 3px 10px;
  margin-bottom: 8px;
  clip-path: polygon(0 0, calc(100% - 6px) 0, 100% 6px, 100% 100%, 6px 100%, 0 calc(100% - 6px));
}

.page-about .about-timeline-body h3 {
  font-family: var(--font-head);
  font-size: 18px;
  font-weight: 700;
  color: #fff;
  margin: 0 0 6px;
}

.page-about .about-timeline-body p {
  font-size: 14px;
  line-height: 1.7;
  color: rgba(236, 240, 241, 0.85);
  margin: 0;
}

.page-about .about-version {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 14px;
  background: rgba(255, 255, 255, 0.1);
  border: 1px solid rgba(255, 255, 255, 0.2);
  padding: 16px 18px;
  clip-path: polygon(0 0, calc(100% - 12px) 0, 100% 12px, 100% 100%, 12px 100%, 0 calc(100% - 12px));
}

.page-about .about-version-no {
  font-family: var(--font-head);
  font-size: 26px;
  font-weight: 800;
  color: var(--border-card);
  line-height: 1;
}

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

.page-about .about-version-list .tag {
  font-size: 12px;
  padding: 5px 10px;
  background: rgba(255, 255, 255, 0.15);
  color: #fff;
}

.page-about .about-update-side {
  display: grid;
  gap: 20px;
  align-content: start;
}

.page-about .about-update-figure {
  margin: 0;
}

.page-about .about-update-figure img {
  width: 100%;
  height: auto;
  max-width: 500px;
  border: 2px solid rgba(255, 255, 255, 0.35);
  clip-path: polygon(0 0, calc(100% - 14px) 0, 100% 14px, 100% 100%, 14px 100%, 0 calc(100% - 14px));
  box-shadow: var(--shadow-soft);
}

.page-about .about-device-panel {
  background: rgba(255, 255, 255, 0.08);
  border: 1px solid rgba(255, 255, 255, 0.2);
  padding: 18px;
  clip-path: polygon(0 0, calc(100% - 14px) 0, 100% 14px, 100% 100%, 14px 100%, 0 calc(100% - 14px));
}

.page-about .about-device-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 14px;
}

.page-about .about-device-title {
  font-family: var(--font-head);
  font-size: 17px;
  font-weight: 700;
  color: #fff;
}

.page-about .about-device-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 12px;
}

.page-about .about-device-card {
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid rgba(255, 255, 255, 0.12);
  padding: 14px;
  text-align: center;
}

.page-about .about-device-abbr {
  display: block;
  font-family: var(--font-head);
  font-size: 22px;
  font-weight: 800;
  color: var(--border-card);
  line-height: 1;
  margin-bottom: 6px;
}

.page-about .about-device-name {
  display: block;
  font-size: 13px;
  color: rgba(236, 240, 241, 0.85);
  margin-bottom: 10px;
}

.page-about .about-device-card .metric-bar {
  height: 6px;
}

.page-about .about-device-figure {
  margin: 16px 0 0;
}

.page-about .about-device-figure img {
  width: 100%;
  height: auto;
  max-width: 300px;
  filter: drop-shadow(0 4px 12px rgba(0, 0, 0, 0.3));
}

/* ===== 桌面端断点 ===== */
@media (min-width: 768px) {
  .page-about .about-hero {
    padding: 56px 0 64px;
  }

  .page-about .about-hero-cols {
    grid-template-columns: 1.3fr 0.7fr;
    gap: 44px;
    align-items: center;
  }

  .page-about .about-hero h1 {
    font-size: 42px;
    line-height: 1.25;
    margin-bottom: 22px;
  }

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

  .page-about .about-hero-fact {
    padding: 22px 18px;
  }

  .page-about .about-hero-num {
    font-size: 38px;
  }

  .page-about .about-section-head .seq-marker {
    font-size: 44px;
  }

  .page-about .about-section-head h2 {
    font-size: 32px;
  }

  .page-about .about-section-head {
    margin-bottom: 40px;
    gap: 24px;
  }

  .page-about .about-coverage-grid {
    grid-template-columns: repeat(4, 1fr);
    gap: 18px;
  }

  .page-about .about-coverage-card {
    padding: 26px 20px 22px;
  }

  .page-about .about-coverage-num {
    font-size: 38px;
  }

  .page-about .about-taxo-wrap {
    grid-template-columns: 1.5fr 0.85fr;
    gap: 36px;
    align-items: start;
  }

  .page-about .about-l1-grid {
    grid-template-columns: repeat(3, 1fr);
    gap: 10px;
  }

  .page-about .about-search-steps {
    grid-template-columns: repeat(2, 1fr);
    gap: 18px;
  }

  .page-about .about-step {
    padding: 24px;
  }

  .page-about .about-update-grid {
    grid-template-columns: 1.2fr 0.8fr;
    gap: 40px;
    align-items: start;
  }

  .page-about .about-timeline::before {
    left: 11px;
  }

  .page-about .about-timeline-item {
    padding-left: 40px;
  }
}

@media (min-width: 1024px) {
  .page-about .about-l1-grid {
    grid-template-columns: repeat(4, 1fr);
  }

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

@media (prefers-reduced-motion: reduce) {
  .page-about .about-coverage-card {
    transition: none;
  }

  .page-about .about-expand-indicator {
    transition: none;
  }

  .page-about .about-step {
    transition: none;
  }
}