/* ===== 页面作用域：品牌历程 /page-about ===== */
.page-about {
  --about-rail-w: 196px;
  --about-axis-gap: 52px;
  --about-card-bg: var(--ink-1);
}

.page-about *,
.page-about *::before,
.page-about *::after {
  box-sizing: border-box;
}

/* ---------- 首屏 ---------- */
.page-about .about-top {
  padding-top: clamp(100px, 13vw, 160px);
  padding-bottom: clamp(24px, 3.6vw, 40px);
}

.page-about .breadcrumb {
  margin-bottom: clamp(20px, 3vw, 34px);
}

.page-about .about-hero {
  max-width: 900px;
}

.page-about .about-hero h1 {
  margin: 0 0 clamp(18px, 2.6vw, 30px);
  font-size: clamp(32px, 6.6vw, 78px);
  line-height: 1.06;
  font-weight: 900;
  font-style: italic;
  letter-spacing: -0.02em;
  color: var(--white);
  text-shadow: 0 0 22px rgba(53, 242, 224, 0.16);
}

.page-about .about-hero .lede {
  margin: 0;
  max-width: 62ch;
  font-size: clamp(16px, 1.35vw, 18px);
  line-height: 1.8;
  color: var(--muted);
}

/* ---------- 长卷主图 ---------- */
.page-about .about-banner {
  margin: 0;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  background: var(--ink-1);
  overflow: hidden;
}

.page-about .about-banner img {
  display: block;
  width: 100%;
  height: auto;
  max-height: 58vh;
  object-fit: cover;
}

/* ---------- 数据条 ---------- */
.page-about .stat-row {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .stat-row > li {
  background: var(--ink-0);
  padding: 18px 20px 20px;
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.page-about .stat-num {
  font-family: var(--mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(26px, 3.6vw, 38px);
  font-weight: 700;
  line-height: 1;
  color: var(--gold);
  letter-spacing: -0.01em;
}

.page-about .stat-label {
  font-size: 13px;
  letter-spacing: 0.06em;
  color: var(--muted);
}

/* ---------- 主体两栏 ---------- */
.page-about .about-body {
  display: grid;
  gap: clamp(32px, 5vw, 60px);
  padding-top: clamp(44px, 6.4vw, 84px);
  padding-bottom: clamp(24px, 4vw, 48px);
}

/* ---------- 左侧时间线导航 ---------- */
.page-about .era-rail-title {
  margin: 0 0 12px;
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--muted);
}

.page-about .era-rail-list {
  list-style: none;
  margin: 0;
  padding: 0 0 12px;
  display: flex;
  gap: 8px;
  overflow-x: auto;
  scrollbar-width: none;
  -webkit-overflow-scrolling: touch;
}

.page-about .era-rail-list::-webkit-scrollbar {
  display: none;
}

.page-about .era-rail-list li {
  flex: 0 0 auto;
}

.page-about .era-rail-list a {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 14px;
  border: 1px solid var(--line);
  background: var(--ink-1);
  color: var(--muted);
  font-size: 13px;
  text-decoration: none;
  white-space: nowrap;
  transition: color 160ms ease, border-color 160ms ease, background 160ms ease;
}

.page-about .era-rail-list a .num {
  font-family: var(--mono);
  font-variant-numeric: tabular-nums;
  font-size: 12px;
  color: var(--cyan);
}

.page-about .era-rail-list a:hover,
.page-about .era-rail-list a:focus-visible {
  color: var(--white);
  border-color: var(--cyan);
  background: rgba(53, 242, 224, 0.07);
  outline: none;
}

/* ---------- 时间轴 ---------- */
.page-about .era-track {
  position: relative;
  min-width: 0;
}

.page-about .era-track::before {
  content: "";
  position: absolute;
  top: 6px;
  bottom: 6px;
  left: 8px;
  width: 1px;
  background: linear-gradient(
    180deg,
    rgba(53, 242, 224, 0.55),
    var(--line) 14%,
    var(--line) 86%,
    rgba(139, 92, 255, 0.55)
  );
}

.page-about .era {
  position: relative;
  padding-left: 40px;
  padding-bottom: clamp(60px, 10vw, 140px);
}

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

.page-about .era-node {
  position: absolute;
  top: 10px;
  left: 8px;
  width: 16px;
  height: 16px;
  margin-left: -8px;
  background: var(--ink-0);
  border: 1px solid var(--cyan);
  box-shadow: 0 0 16px rgba(53, 242, 224, 0.45);
  z-index: 1;
}

.page-about .era-node::after {
  content: "";
  position: absolute;
  inset: 3px;
  border: 1px solid var(--violet);
}

.page-about .era-card {
  position: relative;
  width: 100%;
  padding: clamp(20px, 2.6vw, 30px);
  background: var(--about-card-bg);
  border: 1px solid var(--line);
}

.page-about .era-card::before {
  content: "";
  position: absolute;
  top: -1px;
  left: -1px;
  width: 14px;
  height: 14px;
  border-top: 2px solid var(--cyan);
  border-left: 2px solid var(--cyan);
}

.page-about .era--right .era-card::before {
  border-top-color: var(--violet);
  border-left-color: var(--violet);
}

.page-about .era-year {
  display: block;
  margin: 0 0 12px;
  font-family: var(--mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(30px, 5vw, 54px);
  font-weight: 700;
  font-style: italic;
  line-height: 1;
  letter-spacing: -0.03em;
  color: var(--cyan);
}

.page-about .era--right .era-year {
  color: var(--violet);
}

.page-about .era-card h2 {
  margin: 0 0 14px;
  font-size: clamp(19px, 2.1vw, 26px);
  font-weight: 800;
  line-height: 1.32;
  color: var(--white);
}

.page-about .era-card p {
  margin: 0 0 12px;
  font-size: 16px;
  line-height: 1.75;
  color: var(--muted);
}

.page-about .era-card p:last-child {
  margin-bottom: 0;
}

.page-about .era-points {
  list-style: none;
  margin: 16px 0 0;
  padding: 0;
  display: grid;
  gap: 9px;
}

.page-about .era-points li {
  position: relative;
  padding-left: 18px;
  font-size: 15px;
  line-height: 1.65;
  color: var(--white);
}

.page-about .era-points li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 9px;
  width: 8px;
  height: 1px;
  background: var(--cyan);
}

.page-about .era--right .era-points li::before {
  background: var(--violet);
}

/* ---------- 卡片内图片 ---------- */
.page-about .era-figure {
  margin: 20px 0 0;
  border: 1px solid var(--line);
  background: var(--ink-0);
  overflow: hidden;
}

.page-about .era-figure img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
}

/* ---------- 分段切换 ---------- */
.page-about .segmented {
  margin-top: 20px;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.page-about .segmented-btn {
  flex: 0 0 auto;
}

.page-about .segment-panel {
  flex: 1 0 100%;
}

.page-about .segment-panel[hidden] {
  display: none;
}

.page-about .compare-list {
  margin: 0;
  display: grid;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .compare-row {
  background: var(--ink-0);
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 6px 18px;
  align-items: baseline;
  padding: 13px 16px;
}

.page-about .compare-row dt {
  font-size: 13px;
  color: var(--muted);
  white-space: nowrap;
}

.page-about .compare-row dd {
  margin: 0;
  font-size: 14px;
  line-height: 1.6;
  color: var(--white);
  text-align: right;
}

.page-about .compare-row dd .num {
  font-family: var(--mono);
  font-variant-numeric: tabular-nums;
  font-weight: 700;
  color: var(--gold);
}

/* ---------- 收口 ---------- */
.page-about .about-cta {
  margin-top: clamp(56px, 9vw, 120px);
  padding-top: clamp(34px, 5vw, 58px);
  border-top: 1px solid var(--line);
  display: grid;
  gap: clamp(16px, 2.4vw, 26px);
}

.page-about .about-cta h2 {
  margin: 0;
  font-size: clamp(24px, 3.8vw, 46px);
  font-weight: 900;
  font-style: italic;
  letter-spacing: -0.02em;
  line-height: 1.12;
  color: var(--white);
  text-shadow: 0 0 18px rgba(53, 242, 224, 0.14);
}

.page-about .about-cta p {
  margin: 0;
  max-width: 58ch;
  font-size: 16px;
  line-height: 1.75;
  color: var(--muted);
}

.page-about .cta-links {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

/* ================= 响应式 ================= */

@media (min-width: 640px) {
  .page-about .stat-row {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

@media (min-width: 900px) {
  .page-about .about-body {
    grid-template-columns: var(--about-rail-w) minmax(0, 1fr);
    align-items: start;
  }

  .page-about .era-rail {
    position: sticky;
    top: 112px;
    align-self: start;
  }

  .page-about .era-rail-list {
    flex-direction: column;
    overflow: visible;
    padding: 0;
    gap: 0;
  }

  .page-about .era-rail-list li {
    flex: 1 1 auto;
  }

  .page-about .era-rail-list a {
    display: flex;
    width: 100%;
    padding: 10px 0 10px 14px;
    border: 0;
    border-left: 1px solid var(--line);
    background: transparent;
    white-space: normal;
  }

  .page-about .era-rail-list a:hover,
  .page-about .era-rail-list a:focus-visible {
    border-left-color: var(--cyan);
    background: rgba(53, 242, 224, 0.06);
  }

  .page-about .era-track::before {
    left: 50%;
    margin-left: -0.5px;
  }

  .page-about .era {
    padding-left: 0;
    padding-bottom: clamp(80px, 11vw, 160px);
    display: flow-root;
  }

  .page-about .era-node {
    left: 50%;
    margin-left: -8px;
  }

  .page-about .era-card {
    width: calc(50% - var(--about-axis-gap));
    margin-right: auto;
  }

  .page-about .era--right .era-card {
    margin-right: 0;
    margin-left: auto;
  }
}

@media (max-width: 899px) {
  .page-about .about-banner img {
    aspect-ratio: 16 / 9;
    max-height: none;
  }
}

@media (max-width: 420px) {
  .page-about .stat-row > li {
    padding: 15px 16px 17px;
  }

  .page-about .era-card {
    padding: 18px 16px 20px;
  }

  .page-about .compare-row {
    grid-template-columns: 1fr;
    gap: 4px;
  }

  .page-about .compare-row dd {
    text-align: left;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .era-rail-list a,
  .page-about .cta-links a {
    transition: none;
  }
}
</main>