/* ===== 品牌档案页 page-about ===== */
.page-about {
  background: var(--paper);
  color: var(--ink);
  scroll-behavior: smooth;
}

/* ---------- 首屏档案报头 ---------- */
.page-about .about-hero {
  padding-top: 3rem;
  padding-bottom: 3.25rem;
  border-bottom: 1px solid var(--line);
  background:
    linear-gradient(135deg, var(--paper) 0%, var(--paper-mid) 100%);
}

.page-about .about-hero .breadcrumbs {
  margin-bottom: 2.5rem;
}

.page-about .about-hero .breadcrumbs__item {
  color: var(--ink-faint);
  text-decoration: none;
  font-size: 0.875rem;
}

.page-about .about-hero .breadcrumbs__item[aria-current="page"] {
  color: var(--ink);
  font-weight: 700;
}

.page-about .about-hero__kicker {
  margin: 0 0 1.25rem;
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  letter-spacing: 0.14em;
  color: var(--accent);
  text-transform: uppercase;
}

.page-about .about-hero h1 {
  margin: 0 0 1.5rem;
  max-width: 16em;
  font-size: clamp(1.875rem, 6.5vw, 3.5rem);
  font-weight: 900;
  letter-spacing: -0.02em;
  line-height: 1.12;
}

.page-about .about-hero__lede {
  max-width: 44em;
  margin: 0;
  font-size: 1.125rem;
  line-height: 1.8;
  color: var(--ink-soft);
}

/* ---------- 档案双栏布局 ---------- */
.page-about .about-arch {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2.5rem;
  padding-top: 2.5rem;
  padding-bottom: 5rem;
}

.page-about .about-rail {
  position: static;
}

.page-about .about-rail__inner {
  border-top: 6px solid var(--ink);
  padding-top: 1.25rem;
}

.page-about .about-rail__label {
  margin: 0 0 1.5rem;
  font-size: 0.875rem;
  letter-spacing: 0.08em;
  color: var(--ink-faint);
  font-family: var(--font-mono);
}

.page-about .about-rail__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 0.25rem 1.5rem;
}

.page-about .about-rail__item + .about-rail__item {
  border-top: none;
}

.page-about .about-rail__item a {
  display: flex;
  align-items: baseline;
  gap: 0.75rem;
  padding: 0.625rem 0;
  color: var(--ink);
  text-decoration: none;
  font-weight: 700;
  font-size: 0.9375rem;
  transition: color 0.2s ease;
}

.page-about .about-rail__item a:hover {
  color: var(--accent);
}

.page-about .about-rail__item a .mono {
  color: var(--ink-faint);
  font-size: 0.8125rem;
  font-weight: 500;
  transition: color 0.2s ease;
}

.page-about .about-rail__item a:hover .mono {
  color: var(--accent);
}

.page-about .about-rail__contact {
  margin-top: 1.75rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--line);
}

.page-about .about-rail__tag {
  display: block;
  margin-bottom: 1rem;
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  letter-spacing: 0.12em;
  color: var(--ink-faint);
}

.page-about .about-rail__line {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  line-height: 1.6;
  color: var(--ink-soft);
}

.page-about .about-rail__hours {
  margin: 0.75rem 0 0;
  font-size: 0.8125rem;
  color: var(--ink-faint);
}

/* ---------- 右侧正文容器 ---------- */
.page-about .about-pages {
  display: flex;
  flex-direction: column;
  gap: 5rem;
  min-width: 0;
}

/* ---------- 章节通用 ---------- */
.page-about .ab-sec,
.page-about .ab-appendix {
  scroll-margin-top: 5rem;
}

.page-about .ab-sec__head {
  display: flex;
  align-items: center;
  gap: 1.25rem;
  border-bottom: 3px solid var(--ink);
  padding-bottom: 1rem;
  margin-bottom: 1.5rem;
}

.page-about .ab-sec__num {
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--accent);
  line-height: 1;
}

.page-about .ab-sec__title {
  margin: 0;
  font-size: clamp(1.75rem, 3vw, 2.5rem);
  font-weight: 900;
  letter-spacing: -0.01em;
  line-height: 1.2;
}

.page-about .ab-sec__lede {
  max-width: 46em;
  margin: 0 0 2rem;
  font-size: 1.125rem;
  line-height: 1.8;
  color: var(--ink-soft);
}

/* ---------- 01 档案索引 ---------- */
.page-about .ab-index-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.25rem;
}

.page-about .ab-index-card {
  display: block;
  position: relative;
  padding: 1.75rem;
  background: var(--paper-mid);
  border: 1px solid var(--line);
  color: var(--ink);
  text-decoration: none;
  overflow: hidden;
  transition: border-color 0.2s ease, box-shadow 0.2s ease, transform 0.2s ease;
}

.page-about .ab-index-card::after {
  content: "";
  position: absolute;
  right: 0;
  top: 0;
  width: 0;
  height: 0;
  border-style: solid;
  border-width: 0 0 26px 26px;
  border-color: transparent transparent var(--accent) transparent;
  opacity: 0.6;
}

.page-about .ab-index-card:hover {
  border-color: var(--accent);
  box-shadow: 0 14px 30px rgba(31, 26, 23, 0.1);
  transform: translateY(-2px);
}

.page-about .ab-index-card__num {
  display: block;
  margin-bottom: 1rem;
  font-size: 0.875rem;
  color: var(--accent);
}

.page-about .ab-index-card__title {
  margin: 0 0 0.5rem;
  font-size: 1.25rem;
  font-weight: 800;
}

.page-about .ab-index-card p {
  margin: 0;
  color: var(--ink-soft);
  font-size: 0.9375rem;
  line-height: 1.7;
}

/* ---------- 02 版本里程碑 ---------- */
.page-about .ab-milestone-wrap {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2.25rem;
  align-items: start;
}

.page-about .ab-timeline {
  margin: 0;
  padding: 0;
}

.page-about .ab-milestone {
  position: relative;
  padding: 0 0 2.5rem 3.5rem;
}

.page-about .ab-milestone:not(:last-child)::before {
  content: "";
  position: absolute;
  left: 0.9rem;
  top: 2.6rem;
  bottom: 0;
  width: 2px;
  background: var(--line);
}

.page-about .ab-milestone__num {
  position: absolute;
  left: 0;
  top: 0.2rem;
  z-index: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 2.4rem;
  height: 2.4rem;
  border-radius: 50%;
  background: var(--ink);
  color: var(--paper);
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.02em;
}

.page-about .ab-milestone__content h3 {
  margin: 0 0 0.5rem;
  font-size: 1.375rem;
  font-weight: 800;
}

.page-about .ab-milestone__content p {
  margin: 0;
  color: var(--ink-soft);
  font-size: 0.9375rem;
  line-height: 1.7;
}

.page-about .ab-milestone__note {
  margin-top: 0.75rem;
  padding-left: 0.75rem;
  border-left: 2px solid var(--line);
  color: var(--ink-faint);
  font-size: 0.875rem;
  line-height: 1.6;
  max-height: 10rem;
}

@media (hover: hover) {
  .page-about .ab-milestone__note {
    max-height: 0;
    margin: 0;
    overflow: hidden;
    opacity: 0;
    transform: translateY(4px);
    transition: opacity 0.3s ease, transform 0.3s ease, max-height 0.35s ease, margin 0.3s ease;
  }

  .page-about .ab-milestone:hover .ab-milestone__note,
  .page-about .ab-milestone:focus-within .ab-milestone__note {
    max-height: 10rem;
    margin-top: 0.75rem;
    opacity: 1;
    transform: translateY(0);
  }
}

.page-about .ab-stadium-img {
  margin: 0;
}

.page-about .ab-stadium-img img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  aspect-ratio: 4 / 5;
  object-fit: cover;
  border: 1px solid var(--line);
  background: var(--paper-mid);
}

.page-about .ab-stadium-img figcaption,
.page-about .ab-coverage-map figcaption,
.page-about .ab-sync-img figcaption {
  margin: 0.75rem 0 0;
  color: var(--ink-faint);
  font-size: 0.8125rem;
  line-height: 1.5;
}

/* ---------- 03 数据覆盖与刷新链路 ---------- */
.page-about .ab-coverage-map {
  margin: 2rem 0 0;
}

.page-about .ab-coverage-map img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  aspect-ratio: 16 / 7;
  object-fit: cover;
  border: 1px solid var(--line);
  background: var(--paper-mid);
}

.page-about .ab-table-wrap {
  margin: 2rem 0 0;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}

.page-about .ab-table {
  width: 100%;
  min-width: 520px;
  border-collapse: collapse;
  font-size: 0.9375rem;
}

.page-about .ab-table caption {
  margin-bottom: 0.75rem;
  color: var(--ink-faint);
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  text-align: left;
}

.page-about .ab-table th {
  padding: 1rem 0.875rem;
  border-bottom: 2px solid var(--ink);
  background: var(--paper-mid);
  text-align: left;
  font-size: 0.875rem;
  font-weight: 800;
  white-space: nowrap;
}

.page-about .ab-table td {
  padding: 0.875rem;
  border-bottom: 1px solid var(--line);
  color: var(--ink-soft);
  white-space: nowrap;
}

.page-about .ab-table td:first-child {
  color: var(--ink);
  font-weight: 700;
}

.page-about .ab-pipeline {
  position: relative;
  margin-top: 2.5rem;
  padding: 2.25rem 2rem;
  background: var(--night);
  color: var(--paper);
}

.page-about .ab-pipeline::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 6px;
  background: var(--neon);
}

.page-about .ab-pipeline h3 {
  margin: 0 0 1.25rem;
  font-size: 1.375rem;
  font-weight: 800;
  color: var(--paper);
}

.page-about .ab-pipeline__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
}

.page-about .ab-pipeline__list li {
  padding: 0.5rem 0.875rem;
  background: var(--night-2);
  border: 1px solid var(--night-line);
  color: var(--night-soft);
  font-size: 0.8125rem;
}

.page-about .ab-pipeline__list .mono {
  margin-right: 0.5rem;
  color: var(--neon);
  font-size: 0.75rem;
}

.page-about .ab-pipeline > p {
  margin: 1.25rem 0 0;
  color: var(--night-soft);
  font-size: 0.9375rem;
  line-height: 1.7;
}

/* ---------- 04 合规与备案 ---------- */
.page-about .ab-compliance-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.25rem;
}

.page-about .ab-compliance-item {
  padding: 2rem 1.75rem;
  border-top: 4px solid var(--accent);
  background: var(--paper-mid);
}

.page-about .ab-compliance-item--dark {
  border-top-color: var(--neon);
  background: var(--night);
}

.page-about .ab-compliance-item__label {
  display: block;
  margin-bottom: 1rem;
  color: var(--ink-faint);
  font-size: 0.8125rem;
  letter-spacing: 0.08em;
}

.page-about .ab-compliance-item--dark .ab-compliance-item__label {
  color: var(--night-soft);
}

.page-about .ab-compliance-item__value {
  color: var(--ink);
  font-size: 1.5rem;
  font-weight: 900;
  line-height: 1.35;
}

.page-about .ab-compliance-item--dark .ab-compliance-item__value {
  color: var(--neon);
}

.page-about .ab-compliance-note {
  max-width: 42em;
  margin: 2rem 0 0;
  padding-left: 1.25rem;
  border-left: 4px solid var(--line);
  color: var(--ink-soft);
  font-size: 0.9375rem;
  line-height: 1.8;
}

/* ---------- 05 跨端同步的底层逻辑 ---------- */
.page-about .ab-sync-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2rem;
  padding: 1.75rem;
  background: var(--glass-white);
  border: 1px solid var(--line);
}

.page-about .ab-sync-content h3 {
  margin: 0 0 1.5rem;
  font-size: 1.375rem;
  font-weight: 800;
}

.page-about .ab-sync-steps {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .ab-sync-steps li {
  position: relative;
  padding: 0 0 1.75rem 4rem;
  color: var(--ink-soft);
  font-size: 0.9375rem;
  line-height: 1.7;
}

.page-about .ab-sync-steps li:last-child {
  padding-bottom: 0;
}

.page-about .ab-sync-steps li:not(:last-child)::after {
  content: "";
  position: absolute;
  left: 1.06rem;
  top: 2.25rem;
  bottom: 0;
  width: 2px;
  background: var(--line);
}

.page-about .ab-sync-steps .mono {
  position: absolute;
  left: 0;
  top: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 2.25rem;
  height: 2.25rem;
  border-radius: 2px;
  background: var(--cyan-bright);
  color: var(--night);
  font-size: 0.6875rem;
  font-weight: 800;
  letter-spacing: 0.02em;
}

.page-about .ab-sync-note {
  max-width: 36em;
  margin: 1.5rem 0 0;
  color: var(--ink-faint);
  font-size: 0.875rem;
  line-height: 1.7;
}

.page-about .ab-sync-links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-top: 1.75rem;
}

.page-about .ab-sync-links .btn--ghost {
  border-color: var(--line);
  color: var(--ink);
  transition: border-color 0.2s ease, color 0.2s ease, background 0.2s ease;
}

.page-about .ab-sync-links .btn--ghost:hover {
  border-color: var(--accent);
  color: var(--accent);
}

.page-about .ab-sync-img {
  margin: 0;
  min-width: 0;
}

.page-about .ab-sync-img img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  aspect-ratio: 2 / 1;
  object-fit: cover;
  border: 1px solid var(--line);
  background: var(--paper-mid);
}

/* ---------- 档案附录 ---------- */
.page-about .ab-appendix {
  border-top: 4px solid var(--ink);
  padding-top: 2rem;
}

.page-about .ab-appendix__title {
  margin: 0 0 0.75rem;
  font-size: 1.75rem;
  font-weight: 900;
}

.page-about .ab-appendix > p {
  margin: 0 0 1.5rem;
  color: var(--ink-soft);
  line-height: 1.7;
}

.page-about .ab-appendix__links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.625rem;
}

.page-about .ab-appendix__links a {
  display: inline-flex;
  align-items: center;
  padding: 0.625rem 1.125rem;
  border: 1px solid var(--line);
  background: var(--paper-mid);
  color: var(--ink);
  text-decoration: none;
  font-size: 0.9375rem;
  font-weight: 700;
  transition: border-color 0.2s ease, color 0.2s ease, background 0.2s ease;
}

.page-about .ab-appendix__links a:hover {
  border-color: var(--accent);
  color: var(--accent);
  background: var(--paper);
}

/* ---------- 桌面端增强 ---------- */
@media (min-width: 981px) {
  .page-about .about-arch {
    grid-template-columns: minmax(220px, 260px) minmax(0, 1fr);
    gap: clamp(2.5rem, 5vw, 5.5rem);
    padding-top: 3.5rem;
    padding-bottom: 6rem;
  }

  .page-about .about-rail {
    position: sticky;
    top: 5.25rem;
  }

  .page-about .about-rail__list {
    display: block;
  }

  .page-about .about-rail__item + .about-rail__item {
    border-top: 1px solid var(--line);
  }

  .page-about .about-rail__item a {
    padding: 1rem 0;
  }

  .page-about .about-rail__contact {
    display: block;
  }

  .page-about .ab-milestone-wrap {
    grid-template-columns: minmax(0, 1fr) 300px;
    gap: 2.5rem;
  }

  .page-about .ab-stadium-img {
    position: sticky;
    top: 5.25rem;
  }

  .page-about .ab-index-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 1.5rem;
  }

  .page-about .ab-compliance-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 1.5rem;
  }

  .page-about .ab-sync-grid {
    grid-template-columns: minmax(0, 1fr) minmax(280px, 0.9fr);
    gap: 2.5rem;
    padding: 2.5rem;
  }
}

/* ---------- 窄屏紧凑化 ---------- */
@media (max-width: 560px) {
  .page-about .about-hero {
    padding-top: 2rem;
    padding-bottom: 2.25rem;
  }

  .page-about .about-hero h1 {
    font-size: 1.875rem;
  }

  .page-about .about-hero__lede {
    font-size: 1rem;
  }

  .page-about .about-arch {
    padding-top: 2rem;
    padding-bottom: 4rem;
  }

  .page-about .about-pages {
    gap: 4rem;
  }

  .page-about .ab-sec__head {
    flex-wrap: wrap;
  }

  .page-about .ab-sync-grid {
    padding: 1.25rem;
  }

  .page-about .ab-pipeline {
    padding: 1.5rem 1.25rem;
  }

  .page-about .ab-index-card {
    padding: 1.25rem;
  }

  .page-about .ab-compliance-item {
    padding: 1.5rem 1.25rem;
  }
}