.page-about {
  --about-pad: clamp(16px, 2.6vw, 28px);
  --about-num: clamp(44px, 8.5vw, 112px);
  --about-body: 720px;
}

.page-about .section-head {
  max-width: 760px;
  margin-bottom: 28px;
}

.page-about .section-head .prose {
  color: var(--muted);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  padding-top: 8px;
}

.page-about .about-hero__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(28px, 5vw, 56px);
  align-items: start;
}

.page-about .about-hero h1 {
  font-size: clamp(30px, 5.4vw, 62px);
  line-height: 1.12;
  letter-spacing: -0.02em;
  font-weight: 800;
  margin: 12px 0 18px;
  max-width: 18ch;
}

.page-about .about-hero__lede {
  font-size: clamp(16px, 1.5vw, 18px);
  line-height: 1.78;
  color: var(--text);
  max-width: 60ch;
}

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

.page-about .about-hero__aside {
  background: var(--panel);
  border-left: 3px solid var(--cyan);
  box-shadow: var(--shadow-panel);
  padding: var(--about-pad);
}

.page-about .about-toc {
  list-style: none;
  margin: 14px 0 22px;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.page-about .about-toc a {
  color: var(--text);
  text-decoration: none;
  font-size: 15px;
  border-bottom: 1px solid transparent;
  padding-bottom: 2px;
  transition: color 180ms var(--ease), border-color 180ms var(--ease);
}

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

.page-about .hero-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px;
  border-top: 1px solid var(--line);
  padding-top: 20px;
}

.page-about .hero-stats .stat__value {
  font-size: clamp(22px, 3vw, 30px);
  color: var(--gold);
  display: block;
}

.page-about .hero-stats .stat__label {
  font-size: 13px;
  color: var(--muted);
  display: block;
  margin-top: 4px;
}

/* ---------- 时间轴 ---------- */
.page-about .about-rhythm__figure {
  margin: 0 0 28px;
}

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

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

.page-about .timeline {
  position: relative;
  display: grid;
  grid-template-columns: 1fr;
  gap: 36px;
  margin-top: 24px;
}

.page-about .tl-col {
  display: flex;
  flex-direction: column;
  gap: 18px;
}

.page-about .tl-col__title {
  display: flex;
  align-items: center;
  gap: 10px;
  margin: 0 0 6px;
  font-size: 15px;
  font-weight: 700;
  color: var(--muted);
}

.page-about .tl-node {
  position: relative;
  background: var(--panel);
  border-left: 3px solid var(--accent, var(--cyan));
  box-shadow: var(--shadow-panel);
  padding: 18px 20px;
}

.page-about .tl-node::before {
  content: "";
  position: absolute;
  left: -7px;
  top: 26px;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--accent, var(--cyan));
  box-shadow: 0 0 12px var(--accent, var(--cyan));
}

.page-about .tl-node__when {
  margin: 0 0 6px;
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--accent, var(--cyan));
}

.page-about .tl-node h4 {
  margin: 0 0 8px;
  font-size: 19px;
  font-weight: 700;
  letter-spacing: -0.01em;
}

.page-about .tl-node p:last-child {
  margin: 0;
  font-size: 15px;
  line-height: 1.72;
  color: var(--muted);
}

/* ---------- 版本历程 ---------- */
.page-about .stage-list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .stage {
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
  padding: 28px 0;
  border-top: 1px solid var(--line);
}

.page-about .stage:last-child {
  border-bottom: 1px solid var(--line);
}

.page-about .stage__body {
  max-width: var(--about-body);
}

.page-about .stage__body h3 {
  margin: 0 0 10px;
  font-size: clamp(20px, 2.4vw, 26px);
  font-weight: 800;
  letter-spacing: -0.015em;
}

.page-about .stage__body p {
  margin: 0;
  font-size: 16px;
  line-height: 1.78;
  color: var(--muted);
}

.page-about .stage__aside {
  display: flex;
  align-items: baseline;
  gap: 16px;
}

.page-about .stage__num {
  margin: 0;
  font-size: var(--about-num);
  line-height: 0.85;
  letter-spacing: -0.04em;
  color: #16243a;
  -webkit-text-stroke: 1px var(--line-strong);
}

.page-about .stage__meta {
  margin: 0;
  color: var(--cyan);
  white-space: nowrap;
}

/* ---------- 团队 ---------- */
.page-about .team-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 32px;
  align-items: start;
}

.page-about .team-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.page-about .disclosure {
  background: var(--panel-2);
  border-left: 3px solid var(--accent, var(--cyan));
}

.page-about .disclosure summary {
  cursor: pointer;
  list-style: none;
  padding: 16px 18px;
  font-size: 17px;
  font-weight: 700;
  color: var(--text);
}

.page-about .disclosure summary::-webkit-details-marker {
  display: none;
}

.page-about .disclosure summary::after {
  content: "+";
  float: right;
  font-family: var(--font-mono);
  color: var(--accent, var(--cyan));
}

.page-about .disclosure[open] summary::after {
  content: "–";
}

.page-about .disclosure__body {
  padding: 0 18px 18px;
  color: var(--muted);
}

.page-about .disclosure__body ul {
  margin: 0;
  padding-left: 18px;
  display: flex;
  flex-direction: column;
  gap: 8px;
  font-size: 15px;
  line-height: 1.7;
}

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

/* ---------- 分区与视觉 ---------- */
.page-about .palette-bar {
  display: grid;
  grid-template-columns: repeat(6, minmax(0, 1fr));
  gap: 2px;
  margin: 0 0 24px;
}

.page-about .palette-bar__cell {
  display: block;
  height: 10px;
  background: var(--sw, var(--panel));
}

.page-about .swatch-list {
  list-style: none;
  margin: 24px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 0;
}

.page-about .swatch {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 12px 0 12px 14px;
  border-top: 1px solid var(--line);
  border-left: 3px solid var(--sw, var(--panel));
}

.page-about .swatch__name {
  font-size: 15px;
  color: var(--text);
}

.page-about .note-inline {
  margin: 22px 0 0;
  max-width: 62ch;
  font-size: 15px;
  line-height: 1.75;
  color: var(--muted);
  border-left: 3px solid var(--goldline);
  padding-left: 14px;
}

.page-about .sw-1 { --sw: #0E3B3A; }
.page-about .sw-2 { --sw: #146A63; }
.page-about .sw-3 { --sw: #2BE3D2; }
.page-about .sw-4 { --sw: #7FE9DE; }
.page-about .sw-5 { --sw: #6C4BFF; }
.page-about .sw-6 { --sw: #4A32B8; }
.page-about .sw-7 { --sw: #9B7BFF; }
.page-about .sw-8 { --sw: #94304A; }
.page-about .sw-9 { --sw: #C4526B; }
.page-about .sw-10 { --sw: #E9B44C; }
.page-about .sw-11 { --sw: #8A6B2E; }
.page-about .sw-12 { --sw: #FF5C5C; }

/* ---------- 站点与合作 ---------- */
.page-about .site-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 32px;
  align-items: start;
}

.page-about .site-facts {
  margin: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 0;
}

.page-about .site-facts > div {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 16px;
  padding: 13px 0;
  border-bottom: 1px solid var(--line);
}

.page-about .site-facts dt {
  color: var(--muted);
  font-size: 14px;
  white-space: nowrap;
}

.page-about .site-facts dd {
  margin: 0;
  font-size: 15px;
  color: var(--text);
  text-align: right;
}

.page-about .coop-list {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.page-about .coop {
  background: var(--panel);
  border-top: 3px solid var(--accent, var(--cyan));
  box-shadow: var(--shadow-panel);
  padding: 20px var(--about-pad) 22px;
}

.page-about .coop h3 {
  margin: 0 0 10px;
  font-size: 20px;
  font-weight: 800;
  letter-spacing: -0.01em;
}

.page-about .coop p {
  margin: 0;
  font-size: 15px;
  line-height: 1.76;
  color: var(--muted);
}

.page-about .coop-more {
  margin: 4px 0 0;
}

/* ---------- 结尾 ---------- */
.page-about .about-cta {
  border-top: 1px solid var(--line);
}

.page-about .about-cta h2 {
  font-size: clamp(22px, 3vw, 32px);
  font-weight: 800;
  letter-spacing: -0.02em;
  margin: 0 0 20px;
}

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

/* ---------- 响应式 ---------- */
@media (min-width: 720px) {
  .page-about .palette-bar {
    grid-template-columns: repeat(12, minmax(0, 1fr));
  }

  .page-about .swatch-list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    column-gap: 40px;
  }
}

@media (min-width: 900px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1.5fr) minmax(290px, 1fr);
  }

  .page-about .timeline {
    grid-template-columns: 1fr 1fr;
    gap: 0 64px;
  }

  .page-about .timeline::before {
    content: "";
    position: absolute;
    left: calc(50% - 1px);
    top: 0;
    bottom: 0;
    width: 1px;
    background: var(--line-strong);
  }

  .page-about .stage {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, 0.85fr);
    gap: 24px 48px;
    align-items: start;
    padding: 36px 0;
  }

  .page-about .stage__aside {
    justify-content: flex-end;
    text-align: right;
  }

  .page-about .team-grid {
    grid-template-columns: minmax(0, 1.1fr) minmax(0, 0.9fr);
    gap: 48px;
  }

  .page-about .site-grid {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
    gap: 48px;
  }
}

@media (min-width: 1200px) {
  .page-about .about-hero__grid {
    gap: 72px;
  }

  .page-about .about-hero__aside {
    padding: 30px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-toc a {
    transition: none;
  }
}