/* ===== 页面专属 CSS：.page-about ===== */
.page-about {
  --about-highlight: var(--neon-orange);
  --about-purple: var(--electric-purple);
  --about-cyan: var(--ice-cyan);
  background:
    linear-gradient(165deg, rgba(122, 63, 242, 0.12) 0%, transparent 26%),
    linear-gradient(15deg, rgba(18, 181, 203, 0.06) 0%, transparent 22%),
    var(--space-blue);
  color: var(--off-white);
  min-height: 100vh;
}

.page-about .page-wrap {
  max-width: var(--content-max);
  margin: 0 auto;
  padding: 28px 20px 72px;
}

.page-about .breadcrumbs {
  padding: 16px 0 28px;
  font-family: var(--font-annotation);
  font-size: 13px;
  letter-spacing: 0.02em;
  color: var(--paper-gray);
}

.page-about .breadcrumbs a {
  color: var(--ice-cyan);
  text-decoration: none;
  transition: color 0.2s var(--ease);
}

.page-about .breadcrumbs a:hover {
  color: var(--neon-orange);
}

.page-about .breadcrumbs-sep {
  margin: 0 8px;
  opacity: 0.55;
}

.page-about .section-label {
  font-family: var(--font-annotation);
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--ice-cyan);
}

/* ---------- 编辑布局 ---------- */
.page-about-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 28px;
  align-items: start;
}

.page-about-hero,
.page-about-chapter {
  scroll-margin-top: calc(var(--topbar-height) + 20px);
}

.page-about-hero + .page-about-chapter,
.page-about-chapter + .page-about-chapter {
  margin-top: 56px;
  padding-top: 48px;
  border-top: 1px solid rgba(228, 232, 239, 0.14);
}

/* ---------- 章节索引（左侧窄栏） ---------- */
.page-about-index {
  border-left: 3px solid var(--about-purple);
  padding: 2px 0 2px 16px;
}

.page-about-index .section-label {
  display: inline-block;
  margin-bottom: 10px;
}

.page-about-chapter-num {
  display: block;
  font-family: var(--font-display);
  font-weight: 200;
  font-size: clamp(52px, 8vw, 92px);
  line-height: 0.95;
  letter-spacing: -0.05em;
  color: var(--off-white);
}

.page-about-index h2 {
  font-family: var(--font-heading);
  font-size: clamp(26px, 4vw, 34px);
  line-height: 1.12;
  margin: 10px 0 12px;
  color: var(--off-white);
}

.page-about-index .note {
  margin-left: 0;
}

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

/* ---------- 首屏与目录 ---------- */
.page-about-toc {
  position: relative;
  background: var(--plasma-blue);
  border: 1px solid rgba(122, 63, 242, 0.45);
  padding: 18px 16px;
  box-shadow: 8px 8px 0 rgba(11, 13, 23, 0.35);
}

.page-about-toc-list {
  list-style: none;
  margin: 0 0 14px;
  padding: 0;
}

.page-about-toc-list li {
  border-bottom: 1px dashed rgba(228, 232, 239, 0.22);
}

.page-about-toc-list li:last-child {
  border-bottom: 0;
}

.page-about-toc-list a {
  display: flex;
  align-items: baseline;
  gap: 10px;
  padding: 11px 0;
  color: var(--off-white);
  text-decoration: none;
  font-family: var(--font-annotation);
  font-size: 14px;
  transition: color 0.2s var(--ease), transform 0.2s var(--ease);
}

.page-about-toc-list a:hover {
  color: var(--neon-orange);
  transform: translateX(4px);
}

.page-about-toc-list .index-number {
  font-size: 15px;
  color: var(--neon-orange);
}

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

.page-about-hero-main h1 {
  font-family: var(--font-heading);
  font-size: clamp(34px, 5.6vw, 58px);
  line-height: 1.04;
  letter-spacing: -0.02em;
  margin: 0 0 18px;
  color: var(--off-white);
  max-width: 12em;
}

.page-about-hero-main .page-intro {
  font-size: 17px;
  line-height: 1.75;
  color: var(--paper-gray);
  max-width: 36em;
  margin-bottom: 28px;
}

.page-about-figure-hero {
  margin: 0 0 24px;
}

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

.page-about-hero-copy p + p {
  margin-top: 12px;
}

.page-about-hero-copy .btn {
  margin-top: 18px;
}

/* ---------- 发展历程 ---------- */
.page-about-timeline {
  list-style: none;
  margin: 0;
  padding: 0;
  position: relative;
}

.page-about-timeline::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 12px;
  bottom: 12px;
  width: 1px;
  background: linear-gradient(to bottom, var(--about-purple), var(--about-cyan), var(--about-highlight));
  opacity: 0.7;
}

.page-about-timeline-item {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 6px;
  padding: 20px 0 20px 22px;
  transition: background-color 0.2s var(--ease);
}

.page-about-timeline-item:hover {
  background: rgba(255, 108, 47, 0.04);
}

.page-about-timeline-item::before {
  content: "";
  position: absolute;
  left: 0;
  top: 30px;
  width: 11px;
  height: 11px;
  border-radius: 50%;
  background: var(--space-blue);
  border: 2px solid var(--neon-orange);
  box-shadow: 0 0 0 3px rgba(255, 108, 47, 0.18);
}

.page-about-year {
  font-family: var(--font-display);
  font-weight: 300;
  font-size: clamp(28px, 4vw, 40px);
  line-height: 1;
  letter-spacing: -0.04em;
  color: var(--neon-orange);
}

.page-about-timeline-body h3 {
  font-family: var(--font-heading);
  font-size: 18px;
  line-height: 1.3;
  margin: 2px 0 6px;
  color: var(--off-white);
}

.page-about-timeline-body p {
  margin: 0;
  font-size: 15px;
  line-height: 1.7;
  color: var(--paper-gray);
  max-width: 38em;
}

.page-about-archive-figure {
  margin: 20px 0 0;
}

.page-about-archive-figure img {
  border: 1px solid rgba(228, 232, 239, 0.14);
}

/* ---------- 关键数据 ---------- */
.page-about-metric-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 14px;
}

.page-about-metric {
  position: relative;
  background: var(--plasma-blue);
  border: 1px solid rgba(18, 181, 203, 0.28);
  border-top: 3px solid var(--about-cyan);
  padding: 22px 18px;
  min-height: 150px;
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
  overflow: hidden;
}

.page-about-metric-daily {
  background:
    linear-gradient(150deg, rgba(255, 108, 47, 0.18), transparent 60%),
    var(--plasma-blue);
  border-top-color: var(--neon-orange);
}

.page-about-metric .index-number {
  display: block;
  font-family: var(--font-display);
  font-weight: 400;
  font-size: clamp(34px, 6vw, 52px);
  line-height: 1;
  letter-spacing: -0.03em;
  color: var(--neon-orange);
  margin-bottom: 10px;
}

.page-about-metric h3 {
  font-family: var(--font-heading);
  font-size: 16px;
  line-height: 1.3;
  margin: 0 0 6px;
  color: var(--off-white);
}

.page-about-metric p {
  margin: 0;
  font-size: 14px;
  line-height: 1.65;
  color: var(--paper-gray);
}

/* ---------- 团队与分工 ---------- */
.page-about-team-groups {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 18px;
}

.page-about-team-group {
  background: linear-gradient(145deg, rgba(22, 48, 138, 0.9), rgba(11, 30, 58, 0.96));
  border: 1px solid rgba(122, 63, 242, 0.35);
  border-top: 4px solid var(--about-purple);
  padding: 18px 16px;
}

.page-about-team-group h3 {
  font-family: var(--font-heading);
  font-size: 18px;
  margin: 0 0 10px;
  color: var(--off-white);
}

.page-about-team-list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about-team-list li {
  padding: 8px 0;
  border-bottom: 1px dotted rgba(228, 232, 239, 0.2);
  font-size: 15px;
  line-height: 1.6;
  color: var(--paper-gray);
}

.page-about-team-list li:last-child {
  border-bottom: 0;
}

.page-about-team-list .tag {
  margin-right: 4px;
}

.page-about-help-note {
  margin-top: 20px;
  padding: 14px 16px;
  background: rgba(18, 181, 203, 0.08);
  border-left: 3px solid var(--ice-cyan);
  font-family: var(--font-annotation);
  font-size: 13px;
  line-height: 1.65;
  color: var(--paper-gray);
}

.page-about-help-note p {
  margin: 0;
}

/* ---------- 同步机制 ---------- */
.page-about-sync-figure {
  margin: 0 0 28px;
}

.page-about-sync-figure img {
  border: 1px solid rgba(122, 63, 242, 0.3);
}

.page-about-sync-columns {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 16px;
}

.page-about-sync-block {
  border: 1px solid rgba(122, 63, 242, 0.45);
  border-right: 4px solid var(--about-purple);
  background: rgba(11, 30, 58, 0.7);
  padding: 20px 18px;
}

.page-about-sync-block .index-number {
  display: block;
  font-family: var(--font-display);
  font-size: 20px;
  color: var(--neon-orange);
  margin-bottom: 8px;
}

.page-about-sync-block h3 {
  font-family: var(--font-heading);
  font-size: 17px;
  margin: 0 0 8px;
  color: var(--off-white);
}

.page-about-sync-block p {
  margin: 0;
  font-size: 15px;
  line-height: 1.7;
  color: var(--paper-gray);
}

.page-about-sync-footer {
  margin-top: 28px;
  padding-top: 24px;
  border-top: 1px solid rgba(228, 232, 239, 0.16);
}

.page-about-sync-footer p {
  font-size: 15px;
  line-height: 1.7;
  color: var(--paper-gray);
  max-width: 40em;
  margin: 0 0 16px;
}

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

/* ---------- 桌面端布局 ---------- */
@media (min-width: 900px) {
  .page-about .page-wrap {
    padding: 36px 32px 96px;
  }

  .page-about-layout {
    grid-template-columns: minmax(0, 0.85fr) minmax(0, 2.2fr);
    gap: clamp(28px, 4vw, 52px);
  }

  .page-about-toc {
    position: sticky;
    top: calc(var(--topbar-height) + 24px);
    z-index: 5;
  }

  .page-about-hero {
    padding-top: 12px;
  }

  .page-about-timeline-item {
    grid-template-columns: 140px minmax(0, 1fr);
    gap: 28px;
    padding-left: 34px;
  }

  .page-about-archive-figure {
    margin-left: 168px;
    margin-top: 28px;
  }

  .page-about-metric-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 18px;
  }

  .page-about-metric-daily {
    grid-row: span 2;
    justify-content: center;
    min-height: 320px;
  }

  .page-about-metric-daily .index-number {
    font-size: clamp(64px, 6vw, 88px);
  }

  .page-about-team-groups {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 22px;
  }

  .page-about-team-group:nth-child(2) {
    transform: translateY(24px);
  }

  .page-about-team-group:nth-child(4) {
    transform: translateY(-16px);
  }

  .page-about-sync-columns {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 20px;
  }
}