/* ===== 品牌档案 · 页面专属样式（作用域 .page-about） ===== */

.page-about {
  --about-rail-w: 180px;
  --about-chapter-space: 48px;
  display: block;
  background: var(--c-ink);
  color: var(--c-text);
}

/* ---------- 封面 ---------- */
.page-about .about-cover {
  padding-block: 28px 52px;
}

.page-about .about-title {
  margin: 0 0 22px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(44px, 10vw, 96px);
  line-height: 0.96;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--c-text);
  overflow-wrap: anywhere;
}

.page-about .about-lede {
  max-width: 62ch;
  margin: 0 0 14px;
  font-size: var(--fs-16);
  line-height: 1.72;
  color: var(--c-text);
}

.page-about .about-lede--sub {
  font-size: var(--fs-16);
  color: var(--c-text-dim);
  margin-bottom: 0;
}

.page-about .about-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 26px 20px;
  margin: 44px 0 0;
  padding: 0;
}

.page-about .about-stat {
  min-width: 0;
}

.page-about .about-stat::before {
  content: "";
  display: block;
  width: 30px;
  height: 2px;
  margin-bottom: 12px;
  background: var(--grad-brand);
}

.page-about .about-stat dt {
  margin: 0 0 8px;
  font-family: var(--font-mono);
  font-size: var(--fs-12);
  letter-spacing: 0.12em;
  color: var(--c-muted);
}

.page-about .about-stat dd {
  display: flex;
  align-items: baseline;
  gap: 6px;
  margin: 0;
  min-width: 0;
}

.page-about .about-stat-num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(26px, 4.2vw, 40px);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.01em;
  color: var(--c-text);
}

.page-about .about-stat--key .about-stat-num {
  color: var(--c-orange);
}

.page-about .about-stat-unit {
  font-size: var(--fs-14);
  color: var(--c-muted);
}

/* ---------- 章节骨架 ---------- */
.page-about .about-body {
  padding-bottom: var(--gap-section);
}

.page-about .about-chapter {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 20px;
  padding-block: var(--about-chapter-space);
}

.page-about .about-chapter + .about-chapter {
  border-top: 1px solid var(--c-slate);
}

.page-about .about-chapter--moss,
.page-about .about-chapter--paper {
  border-top: 0;
  padding-inline: 20px;
}

.page-about .about-rail {
  display: flex;
  align-items: baseline;
  gap: 12px;
  min-width: 0;
}

.page-about .about-rail .section-index {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(26px, 4.4vw, 40px);
  line-height: 1;
  letter-spacing: 0.08em;
  color: var(--c-text);
}

.page-about .about-rail .section-index::after {
  content: "";
  display: block;
  width: 34px;
  height: 2px;
  margin-top: 10px;
  background: var(--grad-brand);
}

.page-about .about-rail-note {
  font-family: var(--font-mono);
  font-size: var(--fs-12);
  letter-spacing: 0.06em;
  color: var(--c-muted);
}

.page-about .about-main {
  min-width: 0;
}

.page-about .about-main .prose {
  max-width: 62ch;
}

.page-about .about-main .prose p {
  margin-top: 0;
}

.page-about .about-link {
  color: var(--c-cyan);
  text-decoration: none;
  border-bottom: 1px solid var(--c-slate);
  transition: border-color var(--dur-tap) var(--ease);
}

.page-about .about-link:hover,
.page-about .about-link:focus-visible {
  border-bottom-color: var(--c-cyan);
}

/* ---------- 图片容器补充 ---------- */
.page-about .media img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
}

.page-about .about-banner {
  grid-column: 1 / -1;
  margin: 0 0 12px;
}

.page-about .about-portrait,
.page-about .about-youth-figure {
  margin: 32px 0 0;
}

/* ---------- 01 起点 ---------- */

/* ---------- 02 团队 ---------- */
.page-about .about-roles {
  list-style: none;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 28px;
  margin: 36px 0 0;
  padding: 0;
}

.page-about .about-role {
  min-width: 0;
  border-top: 1px solid var(--c-slate);
  padding-top: 18px;
}

.page-about .about-role-num {
  display: block;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(46px, 8vw, 64px);
  font-weight: 700;
  line-height: 1;
  color: var(--c-text);
  transition: color var(--dur-tap) var(--ease);
}

.page-about .about-role:hover .about-role-num,
.page-about .about-role:focus-within .about-role-num {
  color: var(--c-cyan);
}

.page-about .about-role-name {
  display: block;
  margin-top: 12px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: var(--fs-20);
  letter-spacing: 0.04em;
  color: var(--c-text);
}

.page-about .about-role-desc {
  margin: 8px 0 0;
  font-size: var(--fs-14);
  line-height: 1.78;
  color: var(--c-muted);
}

/* ---------- 03 数据方法 ---------- */
.page-about .about-main--split {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 32px;
}

.page-about .about-steps-col {
  min-width: 0;
}

.page-about .about-steps {
  list-style: none;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 28px;
  margin: 32px 0 0;
  padding: 0;
}

.page-about .about-step {
  position: relative;
  padding-left: 20px;
  border-left: 1px solid var(--c-slate);
  min-width: 0;
}

.page-about .about-step::before {
  content: "";
  position: absolute;
  left: -1px;
  top: 4px;
  width: 1px;
  height: 30px;
  background: var(--grad-brand);
}

.page-about .about-step-num {
  display: block;
  font-family: var(--font-mono);
  font-size: var(--fs-12);
  letter-spacing: 0.14em;
  color: var(--c-cyan);
}

.page-about .about-step h3 {
  margin: 10px 0 8px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: var(--fs-20);
  letter-spacing: 0.03em;
  color: var(--c-text);
}

.page-about .about-step p {
  margin: 0;
  font-size: var(--fs-16);
  line-height: 1.78;
  color: var(--c-text-dim);
  max-width: 58ch;
}

/* ---------- 04 版本时间轴 ---------- */
.page-about .about-timeline {
  list-style: none;
  position: relative;
  margin: 36px 0 0;
  padding: 0 0 0 26px;
}

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 14px;
  bottom: 14px;
  width: 1px;
  background: var(--c-slate);
}

.page-about .about-ver {
  position: relative;
  margin-bottom: 14px;
}

.page-about .about-ver:last-child {
  margin-bottom: 0;
}

.page-about .about-ver::before {
  content: "";
  position: absolute;
  left: -26px;
  top: 22px;
  width: 11px;
  height: 11px;
  border-radius: 50%;
  background: var(--c-ink);
  border: 1px solid var(--c-muted);
  box-sizing: border-box;
  transition: background var(--dur-tap) var(--ease), border-color var(--dur-tap) var(--ease);
}

.page-about .about-ver--current::before {
  background: var(--c-orange);
  border-color: var(--c-orange);
  box-shadow: 0 0 0 4px rgba(255, 106, 26, 0.18);
}

.page-about .about-ver-item > summary {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 14px 16px;
  list-style: none;
  cursor: pointer;
  background: var(--c-night);
  border: 1px solid var(--c-slate);
  border-radius: var(--radius);
  transition: border-color var(--dur-tap) var(--ease);
}

.page-about .about-ver-item > summary::-webkit-details-marker {
  display: none;
}

.page-about .about-ver-item > summary::marker {
  content: "";
}

.page-about .about-ver-item > summary:hover {
  border-color: var(--c-cyan);
}

.page-about .about-ver-item > summary:focus-visible {
  outline: 2px solid var(--c-cyan);
  outline-offset: 2px;
}

.page-about .about-ver-item[open] > summary {
  border-color: var(--c-cyan);
  border-bottom-left-radius: 0;
  border-bottom-right-radius: 0;
}

.page-about .about-ver-tag {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: var(--fs-16);
  font-weight: 700;
  letter-spacing: 0.06em;
  color: var(--c-cyan);
  flex: none;
}

.page-about .about-ver--current .about-ver-tag {
  color: var(--c-orange);
}

.page-about .about-ver-when {
  font-family: var(--font-mono);
  font-size: var(--fs-12);
  letter-spacing: 0.08em;
  color: var(--c-muted);
  flex: none;
}

.page-about .about-ver-name {
  font-size: var(--fs-16);
  color: var(--c-text);
  min-width: 0;
}

.page-about .about-ver-toggle {
  position: relative;
  flex: none;
  width: 14px;
  height: 14px;
  margin-left: auto;
}

.page-about .about-ver-toggle::before,
.page-about .about-ver-toggle::after {
  content: "";
  position: absolute;
  background: var(--c-muted);
  transition: transform var(--dur-tap) var(--ease), background var(--dur-tap) var(--ease);
}

.page-about .about-ver-toggle::before {
  left: 0;
  top: 6px;
  width: 14px;
  height: 1px;
}

.page-about .about-ver-toggle::after {
  left: 6px;
  top: 0;
  width: 1px;
  height: 14px;
}

.page-about .about-ver-item[open] .about-ver-toggle::after {
  transform: scaleY(0);
}

.page-about .about-ver-item[open] .about-ver-toggle::before {
  background: var(--c-cyan);
}

.page-about .about-ver-body {
  padding: 16px 18px 18px;
  background: var(--c-night);
  border: 1px solid var(--c-cyan);
  border-top: 0;
  border-radius: 0 0 var(--radius) var(--radius);
}

.page-about .about-ver-body p {
  margin: 0;
  font-size: var(--fs-14);
  line-height: 1.8;
  color: var(--c-text-dim);
  max-width: 62ch;
}

/* ---------- 05 青训观察 ---------- */
.page-about .about-chapter--moss {
  background: var(--c-moss);
  border-radius: var(--radius);
}

.page-about .about-ages {
  list-style: none;
  display: flex;
  justify-content: space-between;
  gap: 4px;
  position: relative;
  margin: 40px 0 0;
  padding: 0;
}

.page-about .about-ages::before {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  top: 4px;
  height: 1px;
  background: var(--c-slate);
}

.page-about .about-age {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 22px;
  flex: 1 1 0;
  min-width: 0;
}

.page-about .about-age-dot {
  order: -1;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--c-moss);
  border: 1px solid var(--c-cyan);
  box-sizing: border-box;
}

.page-about .about-age-label {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 11px;
  letter-spacing: 0.02em;
  color: var(--c-text-dim);
}

.page-about .about-ages-note {
  margin: 20px 0 0;
  font-family: var(--font-mono);
  font-size: var(--fs-12);
  letter-spacing: 0.06em;
  color: var(--c-muted);
}

/* ---------- 06 协作生态 ---------- */
.page-about .about-reach {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 26px;
  margin: 36px 0 0;
  padding: 0;
}

.page-about .about-reach-item {
  min-width: 0;
  border-top: 1px solid var(--c-slate);
  padding-top: 16px;
}

.page-about .about-reach-item dt {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: var(--fs-12);
  letter-spacing: 0.12em;
  color: var(--c-muted);
}

.page-about .about-reach-item dd {
  margin: 0;
  font-size: var(--fs-14);
  line-height: 1.7;
  color: var(--c-text-dim);
}

.page-about .about-reach-num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: var(--fs-28);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.01em;
  color: var(--c-text);
  margin-right: 4px;
}

/* ---------- 07 纸白章节 ---------- */
.page-about .about-chapter--paper {
  background: var(--c-paper);
  color: var(--c-paper-ink);
  border-radius: var(--radius);
}

.page-about .about-chapter--paper .about-rail .section-index,
.page-about .about-chapter--paper .section-title {
  color: var(--c-paper-ink);
}

.page-about .about-chapter--paper .about-rail-note {
  color: #5C6B70;
}

.page-about .about-chapter--paper .prose p {
  color: var(--c-paper-ink);
}

.page-about .about-chapter--paper .about-link {
  color: var(--c-paper-ink);
  border-bottom-color: rgba(18, 24, 27, 0.32);
}

.page-about .about-chapter--paper .about-link:hover,
.page-about .about-chapter--paper .about-link:focus-visible {
  border-bottom-color: var(--c-orange);
}

.page-about .about-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-top: 32px;
}

/* ---------- 平板及桌面 ---------- */
@media (min-width: 700px) {
  .page-about .about-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 24px;
  }

  .page-about .about-roles {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 32px;
  }

  .page-about .about-reach {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 28px 32px;
  }
}

@media (min-width: 900px) {
  .page-about .about-chapter {
    grid-template-columns: var(--about-rail-w) minmax(0, 1fr);
    gap: 48px;
    padding-block: 96px;
  }

  .page-about .about-chapter--moss,
  .page-about .about-chapter--paper {
    padding-inline: 48px;
  }

  .page-about .about-rail {
    flex-direction: column;
    align-items: flex-start;
    gap: 12px;
    position: sticky;
    top: 104px;
    align-self: start;
  }

  .page-about .about-banner {
    margin-bottom: 24px;
  }

  .page-about .about-roles {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

@media (min-width: 1080px) {
  .page-about .about-main--split {
    grid-template-columns: minmax(0, 1fr) 300px;
    gap: 48px;
    align-items: start;
  }

  .page-about .about-portrait {
    margin-top: 40px;
  }

  .page-about .about-reach {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-role-num,
  .page-about .about-ver-toggle::before,
  .page-about .about-ver-toggle::after,
  .page-about .about-ver::before,
  .page-about .about-ver-item > summary,
  .page-about .about-link {
    transition: none;
  }
}
</main>