.page-about {
  --about-rail: 240px;
  --about-on-night: #C6D0D9;
  --about-night-line: rgba(244, 241, 236, .16);
  background: var(--paper);
  color: var(--ink);
  font-family: var(--font-sans);
  overflow-x: hidden;
}

/* ---------- 通用小件 ---------- */
.page-about .crumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--about-on-night);
  margin: 0 0 clamp(20px, 3vw, 34px);
}
.page-about .crumbs a {
  color: inherit;
  text-decoration: none;
  border-bottom: 1px solid transparent;
}
.page-about .crumbs a:hover { border-bottom-color: var(--sand); }
.page-about .crumb-sep { opacity: .5; }

.page-about .kicker {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: var(--muted);
  margin: 0;
}
.page-about .kicker--sand { color: var(--sand); }
.page-about .kicker--amber { color: var(--amber); }

.page-about .num { font-family: var(--font-mono); font-variant-numeric: tabular-nums; }

.page-about .about-link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 11px 20px;
  border: 2px solid var(--ink);
  background: transparent;
  color: var(--ink);
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: .06em;
  text-decoration: none;
  transition: background var(--t-fast), color var(--t-fast), box-shadow var(--t-fast), border-color var(--t-fast);
}
.page-about .about-link:hover,
.page-about .about-link:focus-visible {
  background: var(--ink);
  color: var(--paper);
  box-shadow: 5px 5px 0 var(--sand);
}
.page-about .about-link--primary {
  background: var(--sand);
  border-color: var(--night-deep);
  color: var(--night-deep);
  font-weight: 700;
  box-shadow: 5px 5px 0 var(--night-deep);
}
.page-about .about-link--primary:hover,
.page-about .about-link--primary:focus-visible {
  background: var(--night-deep);
  color: var(--sand);
  box-shadow: 5px 5px 0 var(--sand);
}
.page-about .about-link--onnight {
  border-color: var(--about-on-night);
  color: var(--paper);
}
.page-about .about-link--onnight:hover,
.page-about .about-link--onnight:focus-visible {
  background: var(--paper);
  color: var(--night-deep);
  box-shadow: 5px 5px 0 var(--sand);
}

.page-about .about-fig { margin: 0; }
.page-about .media-frame img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  background: var(--night);
  color: var(--paper);
  padding: clamp(26px, 4.4vw, 58px) 0 clamp(30px, 4.6vw, 64px);
}
.page-about .about-hero::before {
  content: "";
  position: absolute;
  top: -14%;
  right: -12%;
  width: min(52%, 520px);
  aspect-ratio: 1 / 1;
  background: var(--sand);
  opacity: .16;
  clip-path: polygon(100% 0, 100% 100%, 0 0);
  pointer-events: none;
}
.page-about .about-hero .shell { position: relative; z-index: 1; }

.page-about .about-hero__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(26px, 4vw, 52px);
  align-items: end;
}
.page-about .about-hero__lead h1 {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(36px, 8vw, 82px);
  line-height: .98;
  letter-spacing: -.015em;
  margin: 12px 0 18px;
  text-wrap: balance;
}
.page-about .about-hero__lede {
  max-width: 58ch;
  font-size: clamp(15px, 1.3vw, 18px);
  line-height: 1.65;
  color: var(--about-on-night);
  margin: 0 0 clamp(20px, 2.6vw, 30px);
}
.page-about .about-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.page-about .about-board {
  background: var(--night-deep);
  border: 2px solid var(--sand);
  box-shadow: 8px 8px 0 rgba(232, 106, 44, .38);
  padding: clamp(18px, 2.2vw, 26px);
}
.page-about .board-head {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: var(--amber);
  margin: 0 0 14px;
}
.page-about .board-list { margin: 0; }
.page-about .board-row {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 14px;
  padding: 11px 0;
  border-bottom: 1px solid var(--about-night-line);
}
.page-about .board-row:last-child { border-bottom: 0; padding-bottom: 0; }
.page-about .board-num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(24px, 3.4vw, 34px);
  font-weight: 600;
  color: var(--sand);
  letter-spacing: -.01em;
  line-height: 1;
}
.page-about .board-unit {
  font-size: .5em;
  margin-left: 3px;
  color: var(--amber);
}
.page-about .board-label {
  margin: 0;
  font-size: 13px;
  line-height: 1.4;
  color: var(--about-on-night);
  text-align: right;
}

.page-about .about-strip {
  list-style: none;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--about-night-line);
  border: 1px solid var(--about-night-line);
  margin: clamp(28px, 4vw, 48px) 0 0;
  padding: 0;
}
.page-about .strip-cell {
  background: var(--night);
  padding: 14px 16px;
  display: flex;
  flex-direction: column;
  gap: 4px;
}
.page-about .strip-num {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(24px, 3.2vw, 34px);
  line-height: 1;
  color: var(--paper);
  letter-spacing: -.01em;
}
.page-about .strip-txt {
  font-size: 12.5px;
  letter-spacing: .04em;
  color: var(--about-on-night);
}

/* ---------- 主体分栏 ---------- */
.page-about .about-body {
  background: var(--paper);
  padding: clamp(38px, 5.6vw, 86px) 0 clamp(48px, 6.4vw, 100px);
}
.page-about .about-body__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(24px, 3.2vw, 54px);
  align-items: start;
}

/* ---------- 左侧导读轨 ---------- */
.page-about .about-track { position: relative; }
.page-about .track-head {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--muted);
  margin: 0 0 12px;
}
.page-about .track-list {
  list-style: none;
  margin: 0;
  padding: 0 0 6px;
  display: flex;
  gap: 8px;
  overflow-x: auto;
  scrollbar-width: thin;
}
.page-about .track-item { flex: 0 0 auto; }
.page-about .track-link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 14px;
  border: 2px solid var(--ink);
  background: #fff;
  color: var(--ink);
  font-size: 13px;
  text-decoration: none;
  white-space: nowrap;
  transition: background var(--t-fast), color var(--t-fast);
}
.page-about .track-link:hover,
.page-about .track-link:focus-visible {
  background: var(--night);
  color: var(--paper);
}
.page-about .track-num {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .08em;
  color: var(--sand);
}
.page-about .track-link:hover .track-num,
.page-about .track-link:focus-visible .track-num { color: var(--amber); }

/* ---------- 右侧内容流 ---------- */
.page-about .about-flow {
  display: grid;
  gap: clamp(50px, 6.5vw, 100px);
  min-width: 0;
}
.page-about .about-sec { scroll-margin-top: 96px; }
.page-about .sec-head { max-width: 62ch; }
.page-about .sec-head h2 {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(27px, 4.4vw, 46px);
  line-height: 1.04;
  letter-spacing: -.012em;
  margin: 12px 0 14px;
}
.page-about .sec-lede {
  font-size: clamp(15px, 1.15vw, 17px);
  line-height: 1.68;
  color: var(--muted);
  margin: 0;
}

/* ---------- 团队分工 ---------- */
.page-about .about-sec#duty .about-fig { margin-top: clamp(22px, 3vw, 36px); }
.page-about .duty-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(14px, 1.8vw, 22px);
  margin-top: clamp(24px, 3vw, 38px);
}
.page-about .duty-card {
  border: 2px solid var(--ink);
  border-top-width: 6px;
  background: #fff;
  box-shadow: 7px 7px 0 var(--night-deep);
  padding: clamp(16px, 2vw, 24px);
}
.page-about .duty-card--mint { border-top-color: var(--mint); }
.page-about .duty-card--sand { border-top-color: var(--sand); }
.page-about .duty-card--amber { border-top-color: var(--amber); }
.page-about .duty-sum {
  list-style: none;
  cursor: pointer;
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 10px;
}
.page-about .duty-sum::-webkit-details-marker { display: none; }
.page-about .duty-sum::after {
  content: "展开";
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .08em;
  color: var(--muted);
}
.page-about .duty-card[open] .duty-sum::after { content: "收起"; }
.page-about .duty-sum:focus-visible {
  outline: 3px solid var(--sand);
  outline-offset: 3px;
}
.page-about .duty-tag {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(22px, 2.8vw, 30px);
  line-height: 1;
  letter-spacing: -.01em;
  color: var(--night-deep);
}
.page-about .duty-role {
  font-size: 13px;
  letter-spacing: .03em;
  color: var(--muted);
}
.page-about .duty-list {
  list-style: none;
  margin: 16px 0 0;
  padding: 16px 0 0;
  border-top: 1px solid var(--line);
  display: grid;
  gap: 10px;
}
.page-about .duty-list li {
  position: relative;
  padding-left: 18px;
  font-size: 14.5px;
  line-height: 1.62;
  color: var(--ink);
}
.page-about .duty-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: .62em;
  width: 8px;
  height: 2px;
  background: var(--sand);
}

/* ---------- 数据来源 ---------- */
.page-about .src-seg { margin-top: clamp(22px, 3vw, 34px); }
.page-about .src-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  padding-bottom: 14px;
  border-bottom: 2px solid var(--line);
}
.page-about .src-tab {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: .06em;
  padding: 8px 16px;
  border: 2px solid var(--ink);
  background: transparent;
  color: var(--ink);
  cursor: pointer;
  transition: background var(--t-fast), color var(--t-fast), box-shadow var(--t-fast);
}
.page-about .src-tab[aria-selected="true"] {
  background: var(--ink);
  color: var(--paper);
  box-shadow: 4px 4px 0 var(--sand);
}
.page-about .src-tab:hover { background: var(--night); color: var(--paper); }
.page-about .src-tab:focus-visible {
  outline: 3px solid var(--sand);
  outline-offset: 2px;
}
.page-about .src-panel {
  margin-top: clamp(18px, 2.4vw, 28px);
  background: var(--night);
  color: var(--paper);
  border: 2px solid var(--night-deep);
  padding: clamp(20px, 2.6vw, 34px);
}
.page-about .src-panel[hidden] { display: none; }
.page-about .src-count {
  display: flex;
  align-items: baseline;
  gap: 10px;
  margin: 0 0 12px;
}
.page-about .src-count .num {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(48px, 8vw, 84px);
  line-height: .9;
  letter-spacing: -.02em;
  color: var(--mint);
}
.page-about .src-unit {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--about-on-night);
}
.page-about .src-text {
  max-width: 56ch;
  font-size: 15px;
  line-height: 1.68;
  color: var(--about-on-night);
  margin: 0 0 18px;
}
.page-about .src-chips {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 0;
  padding: 0;
}
.page-about .src-chip {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .06em;
  padding: 6px 12px;
  border: 1px solid var(--about-night-line);
  color: var(--paper);
}
.page-about .src-chip--mint { border-color: var(--mint); color: var(--mint); }

/* ---------- 复核机制 ---------- */
.page-about .review-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(20px, 2.6vw, 36px);
  margin-top: clamp(22px, 3vw, 36px);
  align-items: center;
}
.page-about .review-flow {
  border: 2px solid var(--ink);
  background: #fff;
  padding: clamp(18px, 2.2vw, 28px);
}
.page-about .flow-svg {
  display: block;
  width: 100%;
  height: auto;
}
.page-about .flow-notes {
  list-style: none;
  margin: 18px 0 0;
  padding: 18px 0 0;
  border-top: 1px solid var(--line);
  display: grid;
  gap: 12px;
}
.page-about .flow-notes li {
  font-size: 14.5px;
  line-height: 1.62;
  color: var(--ink);
}
.page-about .flow-notes .num {
  display: block;
  font-size: 11.5px;
  letter-spacing: .1em;
  color: var(--sand);
  margin-bottom: 3px;
}

.page-about .rate-block {
  margin-top: clamp(24px, 3vw, 40px);
  border: 2px solid var(--ink);
  background: #fff;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  box-shadow: 7px 7px 0 var(--night-deep);
}
.page-about .rate-num {
  margin: 0;
  padding: clamp(18px, 2.6vw, 32px);
  background: var(--sand);
  color: var(--night-deep);
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(66px, 13vw, 150px);
  line-height: .82;
  letter-spacing: -.035em;
  display: flex;
  align-items: flex-start;
}
.page-about .rate-pct {
  font-family: var(--font-mono);
  font-size: .26em;
  font-weight: 600;
  margin-left: .12em;
  margin-top: .35em;
}
.page-about .rate-note {
  padding: clamp(18px, 2.6vw, 32px);
  display: flex;
  flex-direction: column;
  justify-content: center;
}
.page-about .rate-note strong {
  display: block;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--muted);
  margin-bottom: 10px;
  font-weight: 500;
}
.page-about .rate-note p {
  margin: 0;
  font-size: 15px;
  line-height: 1.68;
  color: var(--ink);
}

/* ---------- 发展历程 ---------- */
.page-about .about-sec--timeline {
  background: var(--night);
  color: var(--paper);
  border: 2px solid var(--night-deep);
  box-shadow: 9px 9px 0 var(--sand);
  padding: clamp(24px, 3.4vw, 48px);
}
.page-about .sec-head--night h2 { color: var(--paper); }
.page-about .sec-lede--night { color: var(--about-on-night); }
.page-about .about-fig--night { margin-top: clamp(20px, 2.8vw, 34px); }
.page-about .about-fig--night img { filter: saturate(.92); }

.page-about .tl-list {
  list-style: none;
  margin: clamp(26px, 3.4vw, 42px) 0 0;
  padding: 0 0 0 34px;
  position: relative;
  display: grid;
  gap: clamp(20px, 2.6vw, 32px);
}
.page-about .tl-list::before {
  content: "";
  position: absolute;
  left: 7px;
  top: 8px;
  bottom: 8px;
  width: 2px;
  background: linear-gradient(180deg, var(--amber), rgba(242, 179, 61, .12));
}
.page-about .tl-item { position: relative; }
.page-about .tl-item::before {
  content: "";
  position: absolute;
  left: -34px;
  top: 4px;
  width: 16px;
  height: 16px;
  background: var(--night);
  border: 3px solid var(--amber);
}
.page-about .tl-num {
  display: block;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .12em;
  color: var(--amber);
  margin-bottom: 4px;
}
.page-about .tl-era {
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .1em;
  color: var(--about-on-night);
  margin: 0 0 6px;
}
.page-about .tl-body h3 {
  font-size: clamp(17px, 1.5vw, 21px);
  font-weight: 700;
  line-height: 1.32;
  margin: 0 0 8px;
  color: var(--paper);
}
.page-about .tl-body p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.68;
  color: var(--about-on-night);
}

/* ---------- 合作与生态 ---------- */
.page-about .coop-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(14px, 1.8vw, 20px);
  margin-top: clamp(22px, 3vw, 36px);
}
.page-about .coop-card {
  border: 2px solid var(--ink);
  border-left-width: 6px;
  border-left-color: var(--sand);
  background: #fff;
  padding: clamp(16px, 2vw, 24px);
}
.page-about .coop-card--mint { border-left-color: var(--mint); }
.page-about .coop-card--amber { border-left-color: var(--amber); }
.page-about .coop-num {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(38px, 6vw, 60px);
  line-height: .9;
  letter-spacing: -.02em;
  color: var(--night-deep);
  margin: 0 0 8px;
}
.page-about .coop-title {
  font-size: 15px;
  font-weight: 700;
  letter-spacing: .02em;
  margin: 0 0 10px;
  color: var(--ink);
}
.page-about .coop-text {
  margin: 0;
  font-size: 14px;
  line-height: 1.66;
  color: var(--muted);
}

.page-about .handoff {
  margin-top: clamp(24px, 3vw, 40px);
  border: 2px solid var(--ink);
  background: var(--night-deep);
  color: var(--paper);
  padding: clamp(20px, 2.6vw, 34px);
}
.page-about .handoff-head {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--amber);
  margin: 0 0 18px;
}
.page-about .handoff-list {
  list-style: none;
  margin: 0 0 clamp(20px, 2.6vw, 28px);
  padding: 0;
  display: grid;
  gap: 14px;
}
.page-about .handoff-item {
  display: grid;
  grid-template-columns: 28px minmax(0, 1fr);
  gap: 12px;
  align-items: start;
  font-size: 14.5px;
  line-height: 1.62;
  color: var(--about-on-night);
  padding-bottom: 14px;
  border-bottom: 1px solid var(--about-night-line);
}
.page-about .handoff-item:last-child { border-bottom: 0; padding-bottom: 0; }
.page-about .handoff-num {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--sand);
  line-height: 1.62;
}
.page-about .handoff-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}
.page-about .handoff .about-link {
  border-color: var(--about-on-night);
  color: var(--paper);
}
.page-about .handoff .about-link:hover,
.page-about .handoff .about-link:focus-visible {
  background: var(--paper);
  color: var(--night-deep);
  box-shadow: 5px 5px 0 var(--sand);
}
.page-about .handoff .about-link--primary {
  background: var(--sand);
  border-color: var(--sand);
  color: var(--night-deep);
  box-shadow: 5px 5px 0 rgba(244, 241, 236, .22);
}
.page-about .handoff .about-link--primary:hover,
.page-about .handoff .about-link--primary:focus-visible {
  background: var(--paper);
  border-color: var(--paper);
  color: var(--night-deep);
  box-shadow: 5px 5px 0 var(--sand);
}

/* ---------- 页尾衔接 ---------- */
.page-about .about-next {
  border-top: 3px solid var(--ink);
  padding-top: clamp(18px, 2.4vw, 28px);
  display: grid;
  gap: 14px;
}
.page-about .about-next__label {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--muted);
  margin: 0;
}
.page-about .about-next__links {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

/* ---------- 响应式 ---------- */
@media (min-width: 640px) {
  .page-about .about-strip { grid-template-columns: repeat(4, minmax(0, 1fr)); }
  .page-about .coop-grid { grid-template-columns: repeat(3, minmax(0, 1fr)); }
}

@media (min-width: 900px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1.12fr) minmax(0, .88fr);
  }
  .page-about .duty-grid {
    grid-template-columns: repeat(6, minmax(0, 1fr));
    gap: 0 clamp(16px, 2vw, 24px);
  }
  .page-about .duty-card { margin-bottom: clamp(18px, 2.2vw, 26px); }
  .page-about .duty-card:nth-child(1) { grid-column: 1 / span 4; }
  .page-about .duty-card:nth-child(2) { grid-column: 3 / -1; }
  .page-about .duty-card:nth-child(3) { grid-column: 1 / span 4; }
  .page-about .review-grid { grid-template-columns: minmax(0, 1fr) minmax(0, 1.05fr); }
  .page-about .rate-block { grid-template-columns: minmax(0, .62fr) minmax(0, 1fr); }
}

@media (min-width: 1024px) {
  .page-about .about-body__grid {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    gap: clamp(32px, 4vw, 72px);
  }
  .page-about .about-track {
    position: sticky;
    top: 104px;
  }
  .page-about .track-head { margin-bottom: 16px; }
  .page-about .track-list {
    display: block;
    overflow: visible;
    padding: 0 0 0 24px;
    border-left: 2px solid var(--line);
  }
  .page-about .track-item { margin-bottom: 20px; }
  .page-about .track-item:last-child { margin-bottom: 0; }
  .page-about .track-link {
    display: flex;
    border: 0;
    background: none;
    padding: 0;
    white-space: normal;
    font-size: 14px;
  }
  .page-about .track-link:hover,
  .page-about .track-link:focus-visible {
    background: none;
    color: var(--sand);
  }
  .page-about .track-link:hover .track-num,
  .page-about .track-link:focus-visible .track-num { color: var(--sand); }
}

@media (min-width: 1200px) {
  .page-about { --about-rail: 260px; }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-link,
  .page-about .track-link,
  .page-about .src-tab {
    transition: none;
  }
}
</main>