.page-about {
  --about-flow-gap: clamp(24px, 3.5vw, 52px);
}

/* ---------- 面包屑 ---------- */
.page-about .breadcrumbs {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px;
  padding-top: clamp(16px, 2.4vw, 26px);
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: .06em;
  color: var(--muted);
}
.page-about .breadcrumbs a {
  color: var(--muted);
  text-decoration: none;
  transition: color .2s var(--ease);
}
.page-about .breadcrumbs a:hover,
.page-about .breadcrumbs a:focus-visible {
  color: var(--accent);
}
.page-about .breadcrumbs span[aria-hidden="true"] {
  color: var(--line);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  isolation: isolate;
  padding-top: clamp(26px, 4vw, 46px);
  padding-bottom: clamp(30px, 4.5vw, 56px);
}
.page-about .about-hero::before {
  content: "";
  position: absolute;
  top: -20%;
  right: -16%;
  width: min(560px, 72vw);
  aspect-ratio: 1;
  background: conic-gradient(from 200deg, var(--spring), var(--summer), var(--autumn), var(--winter), var(--spring));
  filter: blur(74px);
  opacity: .2;
  z-index: -1;
  pointer-events: none;
}

.page-about .about-hero-grid {
  display: grid;
  gap: clamp(26px, 4vw, 46px);
  align-items: end;
}
@media (min-width: 940px) {
  .page-about .about-hero-grid {
    grid-template-columns: minmax(0, 1.12fr) minmax(0, .88fr);
  }
}

.page-about .about-hero-copy .eyebrow {
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: .2em;
  color: var(--accent);
  margin: 0 0 16px;
}

.page-about .about-hero-copy h1 {
  margin: 0 0 20px;
  font-size: clamp(29px, 5.4vw, 58px);
  line-height: 1.1;
  font-weight: 900;
  letter-spacing: -.02em;
  max-width: 20ch;
}

.page-about .about-hero-copy .lede {
  margin: 0;
  max-width: 46ch;
  font-size: clamp(15px, 1.5vw, 17px);
  line-height: 1.9;
  color: var(--muted);
}

.page-about .about-hero-facts {
  list-style: none;
  margin: clamp(26px, 3.6vw, 38px) 0 0;
  padding: 22px 0 0;
  border-top: 1px solid var(--line);
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(128px, 1fr));
  gap: 18px 20px;
}
.page-about .about-hero-facts li {
  display: grid;
  gap: 5px;
}
.page-about .about-hero-facts .num-lg {
  font-family: var(--mono);
  font-size: clamp(24px, 2.6vw, 30px);
  font-weight: 600;
  color: var(--text);
  letter-spacing: -.01em;
  font-variant-numeric: tabular-nums;
}
.page-about .about-hero-facts .stat-key {
  font-size: 12px;
  letter-spacing: .06em;
  color: var(--muted);
}

/* ---------- 媒体容器 ---------- */
.page-about .media-frame {
  position: relative;
  display: block;
  margin: 0;
  overflow: hidden;
  border-radius: var(--r);
  border: 1px solid var(--line);
  background: var(--panel);
}
.page-about .media-frame img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
}
.page-about .about-hero-media {
  border-radius: 0;
  clip-path: polygon(0 0, 100% 0, 100% 86%, 78% 100%, 0 100%);
}

/* ---------- 主体双栏骨架 ---------- */
.page-about .about-shell {
  display: grid;
  gap: var(--about-flow-gap);
  padding-bottom: clamp(48px, 7vw, 96px);
}
.page-about .about-shell > * {
  min-width: 0;
}
@media (min-width: 1000px) {
  .page-about .about-shell {
    grid-template-columns: 214px minmax(0, 1fr);
    align-items: start;
  }
}

/* ---------- 章节索引 ---------- */
.page-about .about-index-title {
  margin: 0 0 14px;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: .22em;
  color: var(--muted);
}
.page-about .about-index-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}
.page-about .about-index-list a {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 7px 13px;
  font-size: 13px;
  color: var(--muted);
  text-decoration: none;
  border: 1px solid var(--line);
  border-radius: 999px;
  transition: color .22s var(--ease), background .22s var(--ease), border-color .22s var(--ease);
}
.page-about .about-index-list a .num {
  font-family: var(--mono);
  font-size: 11px;
  color: var(--muted);
  font-variant-numeric: tabular-nums;
}
.page-about .about-index-list a:hover,
.page-about .about-index-list a:focus-visible {
  color: var(--text);
  border-color: var(--accent);
  background: rgba(255, 255, 255, .05);
}
@media (min-width: 1000px) {
  .page-about .about-index {
    position: sticky;
    top: calc(var(--hdr) + 26px);
  }
  .page-about .about-index-list {
    flex-direction: column;
    gap: 1px;
  }
  .page-about .about-index-list a {
    border: 0;
    border-left: 2px solid transparent;
    border-radius: 0 4px 4px 0;
    padding: 9px 12px;
    font-size: 14px;
  }
  .page-about .about-index-list a:hover,
  .page-about .about-index-list a:focus-visible {
    border-left-color: var(--accent);
  }
}

/* ---------- 章节 ---------- */
.page-about .about-flow {
  display: grid;
}

.page-about .about-chapter {
  --ch: var(--spring);
  padding-block: clamp(30px, 4.4vw, 54px);
  border-top: 1px solid var(--line);
}
.page-about .about-chapter:first-child {
  border-top: 0;
  padding-top: 0;
}
.page-about .about-chapter--summer { --ch: var(--summer); }
.page-about .about-chapter--autumn { --ch: var(--autumn); }
.page-about .about-chapter--winter { --ch: var(--winter); }

.page-about .about-chapter-head {
  display: flex;
  align-items: baseline;
  gap: 16px;
  margin-bottom: clamp(18px, 2.4vw, 26px);
}
.page-about .about-chapter-num {
  flex: none;
  font-family: var(--mono);
  font-size: clamp(28px, 3.6vw, 42px);
  font-weight: 600;
  line-height: 1;
  letter-spacing: -.02em;
  color: var(--ch);
  font-variant-numeric: tabular-nums;
  transition: text-shadow .3s var(--ease);
}
.page-about .about-chapter[data-current="true"] .about-chapter-num {
  text-shadow: 0 0 24px var(--ch);
}
.page-about .about-chapter-head h2 {
  margin: 0;
  font-size: clamp(21px, 2.5vw, 30px);
  font-weight: 800;
  line-height: 1.3;
  letter-spacing: -.01em;
}

.page-about .about-chapter-body {
  display: grid;
  gap: 20px;
}
.page-about .about-chapter-body p {
  margin: 0;
  max-width: 62ch;
  font-size: clamp(15px, 1.35vw, 16.5px);
  line-height: 1.9;
  color: var(--text);
}

@media (min-width: 820px) {
  .page-about .about-chapter-body--split {
    grid-template-columns: minmax(0, 1.1fr) minmax(0, .9fr);
    align-items: start;
    gap: clamp(22px, 3vw, 40px);
  }
  .page-about .about-chapter-body--split-rev {
    grid-template-columns: minmax(0, .9fr) minmax(0, 1.1fr);
  }
}

.page-about .about-chapter-body blockquote.about-pull {
  margin: 4px 0 0;
  padding: 4px 0 4px 20px;
  border-left: 3px solid var(--ch);
  max-width: 48ch;
  font-size: clamp(16px, 1.7vw, 19px);
  line-height: 1.75;
  color: var(--muted);
}

/* ---------- 团队分布 ---------- */
.page-about .about-team-list {
  list-style: none;
  margin: 8px 0 0;
  padding: 0;
  display: grid;
  gap: 10px;
}
.page-about .about-team-list li {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  padding: 13px 17px;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--r);
  overflow: hidden;
}
.page-about .about-team-list li::before {
  content: "";
  position: absolute;
  inset: 0 auto 0 0;
  width: var(--w, 30%);
  background: var(--tc, var(--winter));
  opacity: .16;
  pointer-events: none;
}
.page-about .about-team-list li[data-season="summer"] { --tc: var(--summer); }
.page-about .about-team-list li[data-season="autumn"] { --tc: var(--autumn); }
.page-about .about-team-list li[data-season="winter"] { --tc: var(--winter); }
.page-about .about-team-list li > * {
  position: relative;
  z-index: 1;
}
.page-about .about-team-label {
  font-size: 14px;
  color: var(--text);
}
.page-about .about-team-list .num {
  font-family: var(--mono);
  font-size: 18px;
  font-weight: 600;
  color: var(--tc, var(--winter));
  font-variant-numeric: tabular-nums;
}

/* ---------- 版本时间轴 ---------- */
.page-about .about-track {
  list-style: none;
  margin: 8px 0 0;
  padding: 0;
  display: grid;
  gap: 22px;
}
@media (min-width: 800px) {
  .page-about .about-track {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 18px;
  }
}
.page-about .about-track-item {
  --tc: var(--spring);
  position: relative;
  padding-top: 18px;
  border-top: 2px solid var(--line);
}
.page-about .about-track-item[data-season="summer"] { --tc: var(--summer); }
.page-about .about-track-item[data-season="autumn"] { --tc: var(--autumn); }
.page-about .about-track-item[data-season="winter"] { --tc: var(--winter); }
.page-about .about-track-item::before {
  content: "";
  position: absolute;
  top: -2px;
  left: 0;
  width: 46px;
  height: 2px;
  background: var(--tc);
}
.page-about .about-track-year {
  display: block;
  font-family: var(--mono);
  font-size: 21px;
  font-weight: 600;
  letter-spacing: -.01em;
  color: var(--tc);
  font-variant-numeric: tabular-nums;
}
.page-about .about-track-item .about-track-title {
  margin: 9px 0 6px;
  max-width: none;
  font-size: 16px;
  font-weight: 700;
  color: var(--text);
}
.page-about .about-track-item .about-track-desc {
  margin: 0;
  max-width: none;
  font-size: 14px;
  line-height: 1.78;
  color: var(--muted);
}

/* ---------- 行动按钮组 ---------- */
.page-about .about-links {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 4px;
}

/* ---------- 使用场景 ---------- */
.page-about .about-users {
  display: grid;
  gap: 14px;
}
@media (min-width: 700px) {
  .page-about .about-users {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}
@media (min-width: 1120px) {
  .page-about .about-users {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}
.page-about .about-user {
  --tc: var(--spring);
  position: relative;
  padding: 22px 18px 20px;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--r);
  overflow: hidden;
}
.page-about .about-user::before {
  content: "";
  position: absolute;
  inset: 0 0 auto 0;
  height: 3px;
  background: var(--tc);
}
.page-about .about-user[data-season="summer"] { --tc: var(--summer); }
.page-about .about-user[data-season="autumn"] { --tc: var(--autumn); }
.page-about .about-user[data-season="winter"] { --tc: var(--winter); }
.page-about .about-users .about-user h3 {
  margin: 0 0 9px;
  font-size: 16px;
  font-weight: 700;
  color: var(--text);
}
.page-about .about-users .about-user p {
  margin: 0;
  max-width: none;
  font-size: 14px;
  line-height: 1.82;
  color: var(--muted);
}

/* ---------- 收尾 ---------- */
.page-about .about-chapter-body p.about-closing {
  margin-top: 4px;
  max-width: 58ch;
  color: var(--muted);
}
.page-about .about-closing a {
  color: var(--accent);
  text-decoration: none;
  border-bottom: 1px solid currentColor;
  padding-bottom: 1px;
}
.page-about .about-closing a:hover,
.page-about .about-closing a:focus-visible {
  color: var(--text);
}