/* ===================== 发展历程 /history/ ===================== */

.page-about {
  --about-rail-w: 164px;
  padding-bottom: 88px;
}

.page-about .breadcrumb {
  margin-top: 26px;
  margin-bottom: 4px;
}

/* ---------- 首屏声明 ---------- */

.page-about .about-hero {
  padding: 34px 0 46px;
  border-bottom: 1px solid var(--line);
}

.page-about .about-hero .eyebrow {
  margin: 0 0 18px;
  color: var(--slate);
}

.page-about .about-hero h1 {
  margin: 0 0 24px;
  font-family: var(--font-display);
  font-weight: 200;
  font-size: clamp(38px, 8.2vw, 92px);
  line-height: 1.02;
  letter-spacing: -0.02em;
  color: var(--ink);
  max-width: 16ch;
}

.page-about .about-hero .lede {
  margin: 0 0 38px;
  max-width: 620px;
  font-size: 17px;
  line-height: 1.85;
  color: var(--ink-2);
}

.page-about .hero-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 22px 18px;
  margin: 0;
}

.page-about .hero-stat {
  margin: 0;
  padding-top: 12px;
  border-top: 2px solid var(--ink);
}

.page-about .hero-stat:nth-child(2) {
  border-top-color: var(--teal);
}

.page-about .hero-stat:nth-child(3) {
  border-top-color: var(--orange);
}

.page-about .hero-stat:nth-child(4) {
  border-top-color: var(--rust);
}

.page-about .hero-stat .stat-label {
  display: block;
  margin: 0 0 6px;
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--slate);
}

.page-about .hero-stat .stat-value {
  margin: 0;
  font-size: 18px;
  font-weight: 500;
  letter-spacing: -0.01em;
  color: var(--ink);
}

/* ---------- 图片容器 ---------- */

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

.page-about .figure-frame {
  position: relative;
  overflow: hidden;
  border-radius: var(--r-m);
  background: var(--sand);
}

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

.page-about .figure-frame--wide {
  aspect-ratio: 1400 / 640;
}

.page-about .figure-frame--tall {
  aspect-ratio: 1200 / 900;
}

.page-about .figure-caption {
  margin-top: 10px;
  font-size: 12px;
  line-height: 1.7;
  letter-spacing: 0.02em;
  color: var(--slate);
}

.page-about .about-lead-figure {
  margin-top: 42px;
}

/* ---------- 主体双区结构 ---------- */

.page-about .about-layout {
  display: block;
  margin-top: 56px;
}

.page-about .rail-caption {
  margin: 0 0 10px;
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--slate);
}

.page-about .version-list {
  display: flex;
  gap: 8px;
  margin: 0;
  padding: 2px 0 12px;
  list-style: none;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  scrollbar-width: thin;
}

.page-about .version-node {
  flex: 0 0 auto;
  margin: 0;
}

.page-about .version-link {
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
  padding: 7px 15px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: var(--cream-soft);
  color: var(--ink);
  text-decoration: none;
  transition: border-color var(--dur) var(--ease),
              background var(--dur) var(--ease),
              color var(--dur) var(--ease);
}

.page-about .version-link:hover,
.page-about .version-link:focus-visible {
  border-color: var(--teal);
  background: var(--cream);
  color: var(--teal-ink);
}

.page-about .version-dot {
  display: none;
}

.page-about .version-tag {
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.06em;
}

.page-about .version-meta {
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--slate);
}

/* ---------- 叙事流 ---------- */

.page-about .history-stream {
  display: flex;
  flex-direction: column;
  gap: 54px;
  margin-top: 40px;
}

.page-about .stage {
  scroll-margin-top: calc(var(--topbar-h) + 24px);
}

.page-about .stage-num {
  display: inline-block;
  margin: 0 0 16px;
  padding-bottom: 3px;
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--teal-ink);
  border-bottom: 1px solid var(--teal);
}

.page-about .stage h2 {
  margin: 0 0 20px;
  max-width: 20ch;
  font-family: var(--font-display);
  font-weight: 300;
  font-size: clamp(25px, 4.4vw, 42px);
  line-height: 1.2;
  letter-spacing: -0.015em;
  color: var(--ink);
}

.page-about .stage .prose {
  margin: 0 0 26px;
  max-width: 34em;
  font-size: 16.5px;
  line-height: 1.85;
  color: var(--ink-2);
}

.page-about .stage-list {
  display: grid;
  gap: 11px;
  max-width: 34em;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .stage-list li {
  position: relative;
  padding-left: 24px;
  font-size: 15px;
  line-height: 1.75;
  color: var(--ink-2);
}

.page-about .stage-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.78em;
  width: 13px;
  height: 1px;
  background: var(--rust);
}

/* 带侧图的阶段 */

.page-about .stage-split {
  display: grid;
  gap: 30px;
}

.page-about .stage-side-figure {
  margin: 0;
}

/* ---------- 中段停顿 ---------- */

.page-about .stage-pause {
  padding: 34px 0 30px;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.page-about .pause-line {
  margin: 0;
  max-width: 16ch;
  font-family: var(--font-display);
  font-weight: 200;
  font-size: clamp(30px, 6.4vw, 66px);
  line-height: 1.15;
  letter-spacing: -0.02em;
  color: var(--ink);
}

/* ---------- 版本轨道 ---------- */

.page-about .edition-track {
  margin: 0;
  padding: 0;
  list-style: none;
  border-top: 1px solid var(--line);
}

.page-about .edition-item {
  display: grid;
  gap: 4px;
  padding: 18px 0;
  border-bottom: 1px solid var(--line);
}

.page-about .edition-no {
  margin: 0;
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--orange);
}

.page-about .edition-text {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--ink-2);
}

/* ---------- 团队 ---------- */

.page-about .team-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
}

.page-about .team-card {
  position: relative;
  overflow: hidden;
  padding: 22px 22px 20px;
  border: 1px solid var(--line);
  border-radius: var(--r-m);
  background: var(--cream-soft);
  transition: border-color var(--dur) var(--ease),
              box-shadow var(--dur) var(--ease),
              transform var(--dur) var(--ease);
}

.page-about .team-card::after {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 3px;
  background: var(--teal);
  transform: scaleY(0.22);
  transform-origin: top;
  transition: transform var(--dur-slow) var(--ease);
}

.page-about .team-card:hover,
.page-about .team-card:focus-within {
  border-color: var(--teal);
  box-shadow: var(--shadow-2);
  transform: translateY(-2px);
}

.page-about .team-card:hover::after,
.page-about .team-card:focus-within::after {
  transform: scaleY(1);
}

.page-about .team-name {
  margin: 0 0 6px;
  font-size: 17px;
  font-weight: 600;
  color: var(--ink);
}

.page-about .team-count {
  margin: 0 0 12px;
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--rust);
}

.page-about .team-duty {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--ink-2);
}

/* ---------- 覆盖范围 ---------- */

.page-about .coverage-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 20px 18px;
  margin: 0 0 36px;
}

.page-about .coverage-item {
  padding-top: 14px;
  border-top: 2px solid var(--teal);
}

.page-about .coverage-value {
  margin: 0 0 6px;
  font-size: clamp(26px, 5vw, 42px);
  font-weight: 500;
  letter-spacing: -0.02em;
  color: var(--ink);
}

.page-about .coverage-label {
  margin: 0;
  font-size: 13px;
  line-height: 1.65;
  color: var(--slate);
}

.page-about .coverage-figure {
  margin-top: 6px;
}

/* ---------- 结尾去向 ---------- */

.page-about .about-cta {
  margin-top: 72px;
  padding: 38px 26px 34px;
  border-radius: var(--r-l);
  background: var(--ink);
  color: var(--cream);
}

.page-about .about-cta .stage-num {
  color: var(--teal);
  border-bottom-color: var(--teal);
}

.page-about .about-cta h2 {
  margin: 0 0 16px;
  max-width: 18ch;
  font-family: var(--font-display);
  font-weight: 300;
  font-size: clamp(24px, 4vw, 38px);
  line-height: 1.22;
  letter-spacing: -0.015em;
  color: var(--cream);
}

.page-about .about-cta p {
  margin: 0;
  max-width: 34em;
  font-size: 16px;
  line-height: 1.85;
  color: rgba(245, 240, 230, 0.78);
}

.page-about .cta-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 26px;
}

.page-about .about-cta .btn-ghost {
  border-color: var(--line-invert);
  color: var(--cream);
}

.page-about .about-cta .btn-ghost:hover,
.page-about .about-cta .btn-ghost:focus-visible {
  border-color: var(--teal);
  color: var(--teal);
}

/* ===================== 媒体查询 ===================== */

@media (min-width: 640px) {
  .page-about .team-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .hero-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 18px;
  }

  .page-about .coverage-grid {
    gap: 20px 24px;
  }
}

@media (min-width: 768px) {
  .page-about .edition-item {
    grid-template-columns: 122px minmax(0, 1fr);
    gap: 26px;
    align-items: baseline;
    padding: 20px 0;
  }

  .page-about .edition-no {
    text-align: right;
  }
}

@media (min-width: 900px) {
  .page-about .stage-split {
    grid-template-columns: minmax(0, 1.1fr) minmax(0, 0.9fr);
    gap: 44px;
    align-items: start;
  }
}

@media (min-width: 1024px) {
  .page-about .about-layout {
    display: grid;
    grid-template-columns: var(--about-rail-w) minmax(0, 1fr);
    gap: 52px;
    align-items: start;
    margin-top: 76px;
  }

  .page-about .version-rail {
    position: sticky;
    top: calc(var(--topbar-h) + 28px);
  }

  .page-about .version-list {
    position: relative;
    flex-direction: column;
    gap: 0;
    padding: 0;
    overflow: visible;
  }

  .page-about .version-list::before {
    content: "";
    position: absolute;
    left: 5px;
    top: 16px;
    bottom: 20px;
    width: 1px;
    background: linear-gradient(180deg, var(--teal) 0%, rgba(23, 195, 178, 0.12) 100%);
  }

  .page-about .version-node {
    position: relative;
  }

  .page-about .version-link {
    display: block;
    padding: 13px 0 13px 26px;
    border: 0;
    border-radius: 0;
    background: transparent;
  }

  .page-about .version-link:hover,
  .page-about .version-link:focus-visible {
    background: transparent;
  }

  .page-about .version-dot {
    display: block;
    position: absolute;
    left: 0;
    top: 50%;
    width: 11px;
    height: 11px;
    margin-top: -5.5px;
    border: 2px solid var(--teal);
    border-radius: 50%;
    background: var(--cream);
    transition: background var(--dur) var(--ease),
                transform var(--dur) var(--ease);
  }

  .page-about .version-link:hover .version-dot,
  .page-about .version-link:focus-visible .version-dot {
    background: var(--teal);
    transform: scale(1.18);
  }

  .page-about .version-tag {
    display: block;
    font-size: 16px;
    color: var(--ink);
    transition: color var(--dur) var(--ease);
  }

  .page-about .version-meta {
    display: block;
    margin-top: 3px;
  }

  .page-about .version-link:hover .version-tag,
  .page-about .version-link:focus-visible .version-tag {
    color: var(--teal-ink);
  }

  .page-about .history-stream {
    margin-top: 0;
    gap: 64px;
  }

  .page-about .rail-caption {
    margin-bottom: 16px;
  }
}

@media (min-width: 1200px) {
  .page-about .about-cta {
    padding: 48px 44px 42px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about *,
  .page-about *::before,
  .page-about *::after {
    transition-duration: 0.001ms !important;
    animation-duration: 0.001ms !important;
  }
}