.page-about {
  --about-yellow-soft: #FFF6D9;
  --about-blue-soft: #E9F1FE;
  --about-green-soft: #E4F7E9;
  --about-timeline-bg: rgba(255, 255, 255, 0.07);
  --about-cell-pad: 0.7rem 0.85rem;
  background: var(--c-page-bg);
}

/* 首屏 hero：非对称编辑部式大标题 + 右栏指标 */
.page-about .about-hero {
  background: linear-gradient(135deg, var(--c-orange-start), var(--c-orange-end));
  padding: clamp(2.5rem, 6vw, 4.5rem) 0 2.75rem;
  border-bottom: 6px solid var(--c-ink);
  position: relative;
  overflow: hidden;
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  inset: 0;
  background-image: repeating-linear-gradient(
    -45deg,
    transparent 0,
    transparent 12px,
    rgba(255, 255, 255, 0.12) 12px,
    rgba(255, 255, 255, 0.12) 13px
  );
  pointer-events: none;
}

.page-about .about-hero__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.75rem 2.5rem;
  position: relative;
  z-index: 1;
}

.page-about .about-hero__kicker {
  color: var(--c-ink);
  font-weight: 700;
  margin-bottom: 0.5rem;
}

.page-about .about-hero h1 {
  font-size: clamp(1.65rem, 3.8vw, 2.8rem);
  line-height: 1.16;
  margin: 0 0 1rem;
  color: var(--c-ink);
  letter-spacing: -0.02em;
}

.page-about .about-hero__lead {
  font-size: 0.95rem;
  line-height: 1.7;
  max-width: 46em;
  color: rgba(26, 26, 46, 0.88);
}

.page-about .about-hero__stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0.75rem;
  margin: 0;
  padding: 0;
}

.page-about .about-stat {
  background: rgba(255, 255, 255, 0.78);
  border-radius: var(--radius);
  padding: 0.95rem 0.85rem;
  backdrop-filter: blur(4px);
  box-shadow: 0 2px 8px rgba(26, 26, 46, 0.1);
}

.page-about .about-stat dt {
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--c-gray-deep);
  font-family: var(--font-mono);
}

.page-about .about-stat__num {
  font-family: var(--font-mono);
  font-size: 1.45rem;
  font-weight: 700;
  color: var(--c-ink);
  margin: 0.2rem 0 0.1rem;
}

.page-about .about-stat__unit {
  font-size: 0.75rem;
  color: var(--c-text);
  opacity: 0.75;
}

/* 面包屑 */
.page-about .about-crumbs {
  padding-top: 0.9rem;
  padding-bottom: 0.9rem;
  font-size: 0.8rem;
  color: var(--c-gray);
  display: flex;
  gap: 0.5rem;
  align-items: center;
}

.page-about .about-crumbs a {
  color: var(--c-blue-deep);
  text-decoration: none;
}

.page-about .about-crumbs a:hover {
  text-decoration: underline;
}

.page-about .about-crumbs [aria-current="page"] {
  font-weight: 700;
  color: var(--c-text);
}

/* 通用区块头 */
.page-about .about-head {
  display: grid;
  gap: 0.6rem 1.5rem;
  margin-bottom: 2rem;
  border-left: 4px solid var(--c-red);
  padding-left: 1rem;
}

.page-about .about-head .kicker {
  font-family: var(--font-mono);
  font-weight: 700;
  color: var(--c-red-deep);
}

.page-about .about-head .section__title {
  margin: 0;
  font-size: clamp(1.35rem, 2.6vw, 1.95rem);
  line-height: 1.2;
}

.page-about .about-head .section__aside {
  font-size: 0.85rem;
  line-height: 1.55;
  color: var(--c-gray-deep);
  max-width: 36em;
}

.page-about .about-head--light {
  border-left-color: var(--c-yellow);
}

.page-about .about-head--light .kicker {
  color: var(--c-yellow);
}

.page-about .about-head--light .section__title {
  color: var(--c-text-light);
}

.page-about .about-head--light .section__aside {
  color: rgba(255, 255, 255, 0.78);
}

/* 01 收录总量与构成 */
.page-about .about-coverage {
  display: grid;
  gap: 1.5rem;
}

.page-about .about-chart {
  margin: 0;
  background: var(--c-card);
  border-radius: var(--radius);
  padding: 1rem;
  box-shadow: 0 2px 10px rgba(26, 26, 46, 0.07);
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
}

.page-about .about-chart img,
.page-about .about-hierarchy__tree img,
.page-about .about-devices__visual img {
  max-width: 100%;
  height: auto;
  object-fit: contain;
  border-radius: calc(var(--radius) - 4px);
}

.page-about .about-chart figcaption {
  font-size: 0.78rem;
  color: var(--c-gray);
  margin-top: 0.5rem;
  font-family: var(--font-mono);
}

.page-about .about-coverage__subgrid {
  display: grid;
  gap: 1.5rem;
  margin-top: 1.5rem;
}

.page-about .about-table-block {
  background: var(--c-card);
  border-radius: var(--radius);
  padding: 1.1rem 1.1rem 1.25rem;
  box-shadow: 0 2px 10px rgba(26, 26, 46, 0.06);
  border-top: 4px solid var(--c-yellow);
}

.page-about .about-table-block:nth-child(2) {
  border-top-color: var(--c-mint);
}

.page-about .about-table-block__title {
  font-size: 0.95rem;
  font-weight: 700;
  margin: 0 0 0.75rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.page-about .about-table-block__title::before {
  content: "";
  width: 8px;
  height: 8px;
  background: var(--c-red);
  border-radius: 2px;
  display: inline-block;
}

.page-about .about-scroll-x {
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  border-radius: calc(var(--radius) - 4px);
}

.page-about .data-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.85rem;
  min-width: 480px;
}

.page-about .data-table__row:nth-child(even) {
  background: var(--c-gray-tint);
}

.page-about .data-table__head {
  background: var(--c-ink);
  color: var(--c-text-light);
  font-weight: 700;
  font-size: 0.8rem;
  text-align: left;
  padding: var(--about-cell-pad);
  white-space: nowrap;
}

.page-about .data-table__cell {
  padding: var(--about-cell-pad);
  border-bottom: 1px solid var(--c-border);
  white-space: nowrap;
}

.page-about .about-cell-num {
  font-family: var(--font-mono);
  font-weight: 700;
  text-align: right;
  color: var(--c-ink);
  background: transparent;
}

.page-about .about-cell-total {
  font-weight: 800;
  background: var(--c-yellow-tint) !important;
  color: var(--c-ink);
  font-family: var(--font-mono);
  border-bottom: 0;
}

/* 02 分类与标签层级 */
.page-about .about-hierarchy {
  display: grid;
  gap: 1.5rem;
}

.page-about .about-hierarchy__tree {
  background: var(--c-card);
  border-radius: var(--radius);
  padding: 1rem;
  box-shadow: 0 2px 10px rgba(26, 26, 46, 0.06);
  align-self: start;
}

.page-about .about-hierarchy__levels {
  display: grid;
  gap: 0.65rem;
  align-content: start;
}

.page-about .about-tier {
  background: var(--c-card);
  border-radius: var(--radius);
  padding: 1rem 1.1rem 1.1rem;
  box-shadow: 0 2px 8px rgba(26, 26, 46, 0.06);
  border-left: 5px solid var(--c-red);
}

.page-about .about-tier:nth-of-type(3) {
  border-left-color: var(--c-blue);
}

.page-about .about-tier:nth-of-type(5) {
  border-left-color: var(--c-green);
}

.page-about .about-tier:nth-of-type(7) {
  border-left-color: var(--c-yellow);
}

.page-about .about-tier__top {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  flex-wrap: wrap;
  margin-bottom: 0.7rem;
}

.page-about .about-tier__top h3 {
  font-size: 1rem;
  margin: 0;
}

.page-about .about-tier__count {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--c-gray-deep);
  margin-left: auto;
  background: var(--c-gray-tint);
  padding: 0.15rem 0.5rem;
  border-radius: 999px;
}

.page-about .about-tier__tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.45rem;
}

.page-about .about-tier__connector {
  text-align: center;
  font-family: var(--font-mono);
  font-weight: 700;
  color: var(--c-gray-deep);
  font-size: 1rem;
  line-height: 1;
  padding: 0.1rem;
  background: var(--c-card);
  border-radius: 50%;
  width: 2rem;
  height: 2rem;
  display: grid;
  place-items: center;
  align-self: center;
  box-shadow: 0 1px 4px rgba(26, 26, 46, 0.12);
}

/* 03 更新批次与节奏 */
.page-about .section--ink {
  background: var(--c-ink);
}

.page-about .about-timeline {
  display: grid;
  gap: 1.5rem;
}

.page-about .about-timeline__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 0.8rem;
}

.page-about .about-batch {
  display: flex;
  gap: 0.9rem;
  background: var(--about-timeline-bg);
  border-radius: var(--radius);
  padding: 0.85rem 1rem;
  border-left: 3px solid var(--c-green);
}

.page-about .about-batch__index {
  font-family: var(--font-mono);
  font-weight: 700;
  color: var(--c-yellow);
  font-size: 1rem;
  min-width: 2.6rem;
}

.page-about .about-batch__body {
  flex: 1;
  min-width: 0;
}

.page-about .about-batch__meta {
  display: flex;
  gap: 0.5rem;
  align-items: center;
  flex-wrap: wrap;
}

.page-about .about-batch__count {
  font-family: var(--font-mono);
  font-weight: 700;
  color: var(--c-green);
  font-size: 0.8rem;
}

.page-about .about-batch__note {
  font-size: 0.8rem;
  color: rgba(255, 255, 255, 0.78);
  margin: 0.35rem 0 0;
  line-height: 1.5;
}

.page-about .about-timeline__rules {
  background: var(--c-ink-soft);
  border-radius: var(--radius);
  padding: 1.25rem;
  color: rgba(255, 255, 255, 0.88);
  align-self: start;
}

.page-about .about-timeline__rules h3 {
  color: var(--c-text-light);
  font-size: 1rem;
  margin: 0 0 0.75rem;
}

.page-about .about-timeline__rules ul {
  margin: 0 0 1rem;
  padding-left: 1.1rem;
  display: grid;
  gap: 0.45rem;
  font-size: 0.85rem;
  line-height: 1.5;
}

.page-about .about-timeline__rules .btn {
  width: 100%;
  justify-content: center;
  text-decoration: none;
}

/* 04 清晰度与字幕对照 */
.page-about .about-quality {
  display: grid;
  gap: 1.25rem;
}

.page-about .about-quality__table {
  min-width: 640px;
}

.page-about .about-quality__table .data-table__cell {
  white-space: nowrap;
}

.page-about .about-quality__meta {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  align-items: center;
}

.page-about .about-quality__chips {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

/* 05 使用场景与设备适配 */
.page-about .about-devices {
  display: grid;
  gap: 1.5rem;
}

.page-about .about-devices__visual {
  background: linear-gradient(150deg, var(--c-blue-tint), var(--c-mint));
  border-radius: var(--radius);
  padding: 1rem;
  display: flex;
  align-items: center;
  justify-content: center;
}

.page-about .about-devices__cards {
  display: grid;
  gap: 1rem;
  align-content: start;
}

.page-about .about-device {
  background: var(--c-card);
  border-radius: var(--radius);
  padding: 1.25rem;
  box-shadow: 0 2px 8px rgba(26, 26, 46, 0.06);
  border-top: 4px solid var(--c-blue);
  display: grid;
  gap: 0.5rem;
}

.page-about .about-device:nth-child(2) {
  border-top-color: var(--c-green);
}

.page-about .about-device:nth-child(3) {
  border-top-color: var(--c-red);
}

.page-about .about-device .badge {
  justify-self: start;
}

.page-about .about-device__title {
  font-size: 1.05rem;
  margin: 0;
}

.page-about .about-device p {
  font-size: 0.85rem;
  line-height: 1.6;
  margin: 0;
  color: var(--c-text);
  opacity: 0.88;
}

.page-about .about-cta-links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  padding-top: 0.5rem;
}

.page-about .about-cta-links .btn {
  text-decoration: none;
  font-weight: 700;
}

/* 桌面端 */
@media (min-width: 768px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1.9fr) minmax(0, 1fr);
    align-items: end;
  }

  .page-about .about-head {
    grid-template-columns: minmax(160px, 0.6fr) minmax(280px, 1.4fr) minmax(200px, 1fr);
    align-items: end;
    border-left: 0;
    border-bottom: 3px solid var(--c-red);
    padding-left: 0;
    padding-bottom: 0.75rem;
  }

  .page-about .about-head .kicker {
    align-self: center;
  }

  .page-about .about-head .section__aside {
    text-align: right;
    justify-self: end;
  }

  .page-about .about-head--light {
    border-bottom-color: var(--c-yellow);
  }

  .page-about .about-coverage {
    grid-template-columns: minmax(260px, 0.75fr) minmax(0, 1.45fr);
    align-items: stretch;
  }

  .page-about .about-coverage__subgrid {
    grid-template-columns: 1fr 1fr;
    margin-top: 1.5rem;
  }

  .page-about .about-hierarchy {
    grid-template-columns: minmax(0, 0.85fr) minmax(0, 1.35fr);
    align-items: start;
  }

  .page-about .about-hierarchy__tree {
    position: sticky;
    top: 1.5rem;
  }

  .page-about .about-timeline {
    grid-template-columns: minmax(0, 1.5fr) minmax(260px, 0.6fr);
    align-items: start;
  }

  .page-about .about-devices {
    grid-template-columns: minmax(280px, 0.75fr) minmax(0, 1.25fr);
    align-items: stretch;
  }

  .page-about .about-devices__cards {
    grid-template-columns: repeat(3, 1fr);
    gap: 1rem;
  }
}

@media (min-width: 1100px) {
  .page-about .about-devices__cards {
    grid-template-columns: 1fr;
  }

  .page-about .about-devices {
    grid-template-columns: minmax(300px, 0.7fr) minmax(0, 1.3fr);
  }
}