.page-about {
  --about-gap: clamp(2.5rem, 5vw, 5rem);
  background: var(--paper);
  color: var(--ink-soft);
  font-family: var(--font-sans);
  overflow-x: hidden;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  border-bottom: 1px solid var(--rule);
  padding: clamp(1.5rem, 4vw, 2.75rem) 0 clamp(2.5rem, 6vw, 4.5rem);
  background-image:
    linear-gradient(180deg, rgba(127, 192, 218, 0.16) 0%, rgba(247, 243, 234, 0) 62%),
    repeating-linear-gradient(90deg, var(--rule) 0 1px, transparent 1px 96px);
  background-repeat: no-repeat, repeat;
  background-size: 100% 100%, auto auto;
  background-position: 0 0, 0 0;
}

.page-about .about-hero-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2rem;
  margin-top: clamp(1.5rem, 3vw, 2.25rem);
}

.page-about .about-hero h1 {
  font-family: var(--font-serif);
  font-weight: 800;
  font-size: clamp(2rem, 6.4vw, 4.1rem);
  line-height: 1.08;
  letter-spacing: -0.02em;
  color: var(--ink);
  margin: 0.6rem 0 0;
  max-width: 15ch;
}

.page-about .about-lede {
  margin: clamp(1rem, 2vw, 1.5rem) 0 0;
  font-size: clamp(1rem, 1.5vw, 1.14rem);
  line-height: 1.9;
  max-width: 56ch;
  color: var(--ink-soft);
}

.page-about .about-facts {
  display: flex;
  flex-wrap: wrap;
  gap: 1.25rem 2.75rem;
  margin-top: clamp(1.5rem, 3vw, 2.25rem);
  padding-top: 1.25rem;
  border-top: 1px solid var(--rule);
}

.page-about .fact {
  display: flex;
  flex-direction: column;
  gap: 0.2rem;
  min-width: 6.5rem;
}

.page-about .fact-num {
  font-family: var(--font-mono);
  font-size: clamp(1.6rem, 3.4vw, 2.4rem);
  line-height: 1;
  font-weight: 700;
  color: var(--ink);
  letter-spacing: 0;
}

.page-about .fact-unit {
  font-size: 0.6em;
  margin-left: 0.1em;
  color: var(--orange);
}

.page-about .fact-label {
  font-size: 0.78rem;
  letter-spacing: 0.06em;
  color: var(--ink-soft);
  opacity: 0.82;
}

/* 覆盖面板 */
.page-about .hero-panel {
  background: var(--ink);
  color: var(--paper-on-ink);
  border-top: 4px solid var(--green);
  padding: 1.35rem 1.25rem 1.5rem;
}

.page-about .panel-title {
  margin: 0 0 1rem;
  font-size: 0.75rem;
  letter-spacing: 0.14em;
  color: var(--green-pale);
  font-weight: 600;
}

.page-about .panel-list {
  margin: 0;
  display: grid;
  gap: 0;
}

.page-about .panel-row {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.55rem 0;
  border-bottom: 1px solid rgba(239, 233, 220, 0.18);
}

.page-about .panel-row:last-child {
  border-bottom: 0;
}

.page-about .panel-row dt {
  font-size: 0.86rem;
  color: rgba(239, 233, 220, 0.78);
}

.page-about .panel-row dd {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--blue-pale);
}

/* ---------- 主体双栏 ---------- */
.page-about .about-body {
  padding: var(--about-gap) 0 calc(var(--about-gap) * 1.2);
}

.page-about .about-layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2.5rem;
}

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

/* ---------- 章节 ---------- */
.page-about .chapter {
  padding-top: clamp(2rem, 4vw, 3.25rem);
  margin-top: clamp(2rem, 4vw, 3.25rem);
  border-top: 1px solid var(--rule);
  scroll-margin-top: 6.5rem;
}

.page-about .chapter:first-child {
  margin-top: 0;
  padding-top: 0;
  border-top: 0;
}

.page-about .chapter-head {
  display: flex;
  align-items: baseline;
  gap: 0.85rem;
  margin-bottom: 1.1rem;
}

.page-about .chapter-num {
  flex: none;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  color: var(--green);
  border: 1px solid var(--green-pale);
  padding: 0.15rem 0.4rem;
}

.page-about .chapter h2 {
  font-family: var(--font-serif);
  font-weight: 800;
  font-size: clamp(1.35rem, 3vw, 2.05rem);
  line-height: 1.28;
  letter-spacing: -0.01em;
  color: var(--ink);
  margin: 0;
}

.page-about .chapter-body p {
  max-width: 66ch;
  line-height: 1.88;
  margin: 0 0 1em;
  font-size: 1rem;
}

.page-about .chapter-body p:last-child {
  margin-bottom: 0;
}

.page-about .chapter-body a {
  color: var(--blue);
  text-decoration: underline;
  text-underline-offset: 3px;
  text-decoration-thickness: 1px;
}

.page-about .chapter-body a:hover {
  color: var(--orange);
}

/* ---------- 图片 ---------- */
.page-about .about-figure {
  margin: 1.5rem 0 1.75rem;
  border: 1px solid var(--rule);
  background: var(--ink);
}

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

.page-about .about-figure .media-caption {
  background: var(--paper);
  border-top: 1px solid var(--rule);
  padding: 0.65rem 0.9rem;
  font-size: 0.82rem;
  line-height: 1.7;
  color: var(--ink-soft);
}

/* ---------- 团队色块条 ---------- */
.page-about .team-bands {
  display: flex;
  gap: 3px;
  height: 16px;
  margin: 1.75rem 0 0;
}

.page-about .team-bands .band {
  flex: 1 1 0;
}

.page-about .team-bands .band:nth-child(1) { background: var(--blue); flex-grow: 1.25; }
.page-about .team-bands .band:nth-child(2) { background: var(--green); flex-grow: 1.1; }
.page-about .team-bands .band:nth-child(3) { background: var(--blue-pale); flex-grow: 1; }
.page-about .team-bands .band:nth-child(4) { background: var(--green-pale); flex-grow: 1.05; }
.page-about .team-bands .band:nth-child(5) { background: var(--orange-pale); flex-grow: 0.95; }

.page-about .team-list {
  list-style: none;
  margin: 1.5rem 0 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--rule);
  border: 1px solid var(--rule);
}

.page-about .team-item {
  background: var(--paper);
  padding: 1.1rem 1.05rem 1.2rem;
  border-left: 3px solid var(--rule);
}

.page-about .team-item:nth-child(1) { border-left-color: var(--blue); }
.page-about .team-item:nth-child(2) { border-left-color: var(--green); }
.page-about .team-item:nth-child(3) { border-left-color: var(--blue-pale); }
.page-about .team-item:nth-child(4) { border-left-color: var(--green-pale); }
.page-about .team-item:nth-child(5) { border-left-color: var(--orange-pale); }

.page-about .team-item h3 {
  font-family: var(--font-serif);
  font-size: 1.02rem;
  font-weight: 700;
  color: var(--ink);
  margin: 0 0 0.4rem;
}

.page-about .team-item p {
  margin: 0;
  font-size: 0.92rem;
  line-height: 1.78;
}

/* ---------- 流程 ---------- */
.page-about .flow {
  list-style: none;
  margin: 1.5rem 0 1.5rem;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  background: var(--rule);
  border: 1px solid var(--rule);
}

.page-about .flow-step {
  background: var(--paper);
  padding: 1.15rem 1.05rem 1.3rem;
  box-shadow: inset 0 3px 0 0 var(--blue);
}

.page-about .flow-step:nth-child(2) { box-shadow: inset 0 3px 0 0 var(--green); }
.page-about .flow-step:nth-child(3) { box-shadow: inset 0 3px 0 0 var(--blue-pale); }
.page-about .flow-step:nth-child(4) { box-shadow: inset 0 3px 0 0 var(--orange); }

.page-about .flow-num {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  font-weight: 700;
  color: var(--ink-soft);
  opacity: 0.55;
  margin-bottom: 0.35rem;
}

.page-about .flow-step h3 {
  font-family: var(--font-serif);
  font-size: 1.02rem;
  font-weight: 700;
  color: var(--ink);
  margin: 0 0 0.4rem;
}

.page-about .flow-step p {
  margin: 0;
  font-size: 0.9rem;
  line-height: 1.76;
}

/* ---------- 合作生态 ---------- */
.page-about .eco-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1rem;
  margin-top: 1.5rem;
}

.page-about .eco-card {
  border: 1px solid var(--rule);
  border-top: 3px solid var(--green);
  background: var(--paper);
}

.page-about .eco-card:nth-child(2) { border-top-color: var(--blue); }
.page-about .eco-card:nth-child(3) { border-top-color: var(--orange); }

.page-about .eco-card summary {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 1rem;
  cursor: pointer;
  padding: 1rem 1.05rem;
  list-style: none;
  font-family: var(--font-serif);
  font-weight: 700;
  color: var(--ink);
}

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

.page-about .eco-card summary::after {
  content: "＋";
  font-family: var(--font-sans);
  font-weight: 400;
  font-size: 0.95rem;
  color: var(--ink-soft);
  opacity: 0.6;
  margin-left: 0.35rem;
}

.page-about .eco-card[open] summary::after {
  content: "－";
}

.page-about .eco-name {
  font-size: 1rem;
}

.page-about .eco-count {
  flex: none;
  font-family: var(--font-mono);
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--orange);
}

.page-about .eco-card p {
  margin: 0;
  padding: 0 1.05rem 1.15rem;
  font-size: 0.92rem;
  line-height: 1.8;
  border-top: 1px solid var(--rule);
  padding-top: 0.85rem;
}

/* ---------- 时间线 ---------- */
.page-about .timeline-wrap {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2rem;
  margin-top: 1.5rem;
}

.page-about .timeline {
  list-style: none;
  margin: 0;
  padding: 0 0 0 1.4rem;
  border-left: 1px solid var(--rule);
}

.page-about .tl-item {
  position: relative;
  margin-bottom: 0.85rem;
}

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

.page-about .tl-item::before {
  content: "";
  position: absolute;
  left: -1.4rem;
  top: 1.05rem;
  width: 9px;
  height: 9px;
  margin-left: -5px;
  background: var(--green);
}

.page-about .tl-item:nth-child(3)::before { background: var(--blue); }
.page-about .tl-item:nth-child(6)::before { background: var(--orange); }

.page-about .tl-card {
  border: 1px solid var(--rule);
  border-left: 3px solid var(--green);
  background: var(--paper);
}

.page-about .tl-item:nth-child(3) .tl-card { border-left-color: var(--blue); }
.page-about .tl-item:nth-child(6) .tl-card { border-left-color: var(--orange); }

.page-about .tl-card summary {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 0.5rem 0.75rem;
  cursor: pointer;
  padding: 0.85rem 1rem;
  list-style: none;
}

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

.page-about .tl-year {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--green);
  border: 1px solid var(--green-pale);
  padding: 0.08rem 0.35rem;
  flex: none;
}

.page-about .tl-title {
  font-family: var(--font-serif);
  font-size: 1rem;
  font-weight: 700;
  color: var(--ink);
  line-height: 1.5;
}

.page-about .tl-card p {
  margin: 0;
  padding: 0.8rem 1rem 1rem;
  border-top: 1px solid var(--rule);
  font-size: 0.9rem;
  line-height: 1.8;
}

.page-about .tl-card p a {
  color: var(--blue);
  text-decoration: underline;
  text-underline-offset: 3px;
}

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

/* ---------- 准则 ---------- */
.page-about .rule-list {
  list-style: none;
  margin: 1.5rem 0 1.75rem;
  padding: 0;
  display: grid;
  gap: 1.25rem;
}

.page-about .rule-item {
  padding-left: 1rem;
  border-left: 1px solid var(--rule);
}

.page-about .rule-item h3 {
  font-family: var(--font-serif);
  font-size: 1.02rem;
  font-weight: 700;
  color: var(--ink);
  margin: 0 0 0.35rem;
}

.page-about .rule-item h3::before {
  content: "";
  display: inline-block;
  width: 8px;
  height: 8px;
  margin-right: 0.5rem;
  background: var(--orange);
  vertical-align: 0.08em;
}

.page-about .rule-item p {
  margin: 0;
  font-size: 0.92rem;
  line-height: 1.8;
  max-width: 62ch;
}

/* ---------- 结尾 ---------- */
.page-about .chapter--cta {
  background: var(--ink);
  color: var(--paper-on-ink);
  padding: clamp(1.75rem, 4vw, 2.75rem) clamp(1.25rem, 3vw, 2.25rem);
  border-top: 4px solid var(--orange);
  margin-top: clamp(2.25rem, 4vw, 3.5rem);
}

.page-about .chapter--cta h2 {
  color: var(--paper-on-ink);
}

.page-about .chapter--cta .chapter-num {
  color: var(--orange-pale);
  border-color: rgba(244, 177, 131, 0.5);
}

.page-about .chapter--cta .chapter-body p {
  color: rgba(239, 233, 220, 0.86);
}

.page-about .cta-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.85rem;
  margin-top: 1.5rem;
}

/* ---------- 侧栏目录 ---------- */
.page-about .about-aside {
  min-width: 0;
}

.page-about .toc {
  border: 1px solid var(--rule);
  border-top: 3px solid var(--ink);
  background: var(--paper);
  padding: 1.1rem 1.1rem 1.25rem;
}

.page-about .toc-title {
  margin: 0 0 0.85rem;
  font-size: 0.75rem;
  letter-spacing: 0.14em;
  font-weight: 600;
  color: var(--ink);
  padding-bottom: 0.6rem;
  border-bottom: 1px solid var(--rule);
}

.page-about .toc-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 0.15rem;
  counter-reset: toc;
}

.page-about .toc-list li {
  counter-increment: toc;
}

.page-about .toc-list a {
  display: flex;
  gap: 0.55rem;
  padding: 0.4rem 0.15rem;
  font-size: 0.86rem;
  line-height: 1.6;
  color: var(--ink-soft);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color 180ms var(--ease), border-color 180ms var(--ease);
}

.page-about .toc-list a::before {
  content: counter(toc, decimal-leading-zero);
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--green);
  flex: none;
  padding-top: 0.15rem;
}

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

/* ---------- 平板及以上 ---------- */
@media (min-width: 700px) {
  .page-about .about-hero-grid {
    grid-template-columns: minmax(0, 1.35fr) minmax(260px, 0.65fr);
    gap: clamp(2rem, 4vw, 3.5rem);
    align-items: end;
  }

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

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

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

  .page-about .rule-list {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 1.5rem;
  }

  .page-about .timeline-wrap {
    grid-template-columns: minmax(0, 1.6fr) minmax(200px, 0.75fr);
    align-items: start;
    gap: clamp(1.75rem, 3vw, 2.75rem);
  }
}

/* ---------- 桌面双栏 ---------- */
@media (min-width: 1024px) {
  .page-about .about-layout {
    grid-template-columns: minmax(0, 1fr) 286px;
    gap: clamp(2.75rem, 5vw, 5rem);
    align-items: start;
  }

  .page-about .about-aside {
    position: sticky;
    top: 5.5rem;
    max-height: calc(100vh - 7rem);
    overflow-y: auto;
    scrollbar-width: thin;
  }
}

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