.page-about {
  --about-measure: 64ch;
  --about-hair: rgba(244, 247, 245, .12);
  display: block;
}

/* ---------- 面包屑 ---------- */
.page-about .crumbs {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 13px;
  letter-spacing: .08em;
  color: var(--muted);
}

.page-about .crumbs a {
  color: var(--muted);
  text-decoration: none;
  transition: color var(--dur) var(--ease);
}

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

.page-about .crumbs [aria-current] {
  color: var(--paper);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  padding-block: clamp(28px, 5vw, 56px) clamp(36px, 6vw, 72px);
}

.page-about .about-hero .crumbs {
  margin-bottom: clamp(32px, 5vw, 64px);
}

.page-about .about-hero__kicker {
  margin: 0 0 clamp(18px, 2.5vw, 26px);
  color: var(--pitch);
}

.page-about .about-hero__title {
  margin: 0 0 clamp(20px, 3vw, 32px);
  max-width: 15ch;
  font-weight: 250;
  line-height: 1.08;
}

.page-about .about-hero__lede {
  margin: 0;
  max-width: var(--about-measure);
  color: var(--paper);
}

.page-about .about-facts {
  margin-top: clamp(36px, 5vw, 64px);
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--about-hair);
  border: 1px solid var(--about-hair);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 18px), calc(100% - 18px) 100%, 0 100%);
}

.page-about .about-fact {
  background: var(--ink);
  padding: 18px 16px 20px;
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.page-about .about-fact .num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-weight: 700;
  font-size: clamp(1.75rem, 5.5vw, 2.4rem);
  line-height: 1;
  color: var(--pitch);
}

.page-about .about-fact__label {
  font-size: 13px;
  line-height: 1.5;
  letter-spacing: .04em;
  color: var(--muted);
}

/* ---------- 22 度斜线分隔 ---------- */
.page-about .about-slash {
  position: relative;
  height: 1px;
  margin: 0 clamp(20px, 5vw, 40px);
  background: var(--about-hair);
}

.page-about .about-slash::after {
  content: "";
  position: absolute;
  right: 0;
  top: -11px;
  width: 46px;
  height: 22px;
  background: var(--ink);
  border-left: 1px solid var(--halo-strong);
  transform: skewX(-22deg);
}

/* ---------- 选题三条线 ---------- */
.page-about .about-why__lede,
.page-about .about-flow__lede,
.page-about .about-team__lede,
.page-about .about-history__lede,
.page-about .about-coop__lede,
.page-about .about-annual__lede {
  max-width: var(--about-measure);
}

.page-about .topic-lines {
  list-style: none;
  margin: clamp(32px, 5vw, 56px) 0 0;
  padding: 0;
  border-top: 1px solid var(--about-hair);
}

.page-about .topic-line {
  position: relative;
  display: grid;
  gap: 10px;
  padding: clamp(24px, 3.4vw, 38px) 0;
  border-bottom: 1px solid var(--about-hair);
}

.page-about .topic-line__when {
  justify-self: start;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: .2em;
  color: var(--alert);
}

.page-about .topic-line__title {
  margin: 0;
}

.page-about .topic-line__text {
  margin: 0;
  max-width: var(--about-measure);
  color: var(--muted);
}

.page-about .topic-line::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: -1px;
  width: 56px;
  height: 2px;
  background: var(--pitch);
  transform: skewX(-22deg);
  transform-origin: left bottom;
}

/* ---------- 工作流 ---------- */
.page-about .flow-list {
  list-style: none;
  margin: clamp(32px, 5vw, 56px) 0 0;
  padding: 0;
  display: grid;
  gap: clamp(16px, 2vw, 24px);
}

.page-about .flow-item {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 14px clamp(16px, 2.4vw, 32px);
  padding: clamp(18px, 2.4vw, 26px);
  background: var(--panel);
  border: 1px solid var(--about-hair);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - var(--cut)), calc(100% - var(--cut)) 100%, 0 100%);
}

.page-about .flow-item__no {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-weight: 700;
  font-size: clamp(1.25rem, 3vw, 1.6rem);
  line-height: 1;
  color: var(--pitch);
}

.page-about .flow-item__body h3 {
  margin: 0 0 8px;
}

.page-about .flow-item__body p {
  margin: 0;
  max-width: var(--about-measure);
  color: var(--muted);
}

/* ---------- 图片 ---------- */
.page-about .about-shot {
  margin: clamp(32px, 5vw, 56px) 0 0;
  background: var(--panel);
  border: 1px solid var(--about-hair);
  overflow: hidden;
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 18px), calc(100% - 18px) 100%, 0 100%);
}

.page-about .about-shot img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  object-fit: cover;
  filter: saturate(.92) contrast(1.04);
}

.page-about .about-shot__cap {
  padding: 14px 18px 18px;
  border-top: 1px solid var(--about-hair);
  font-size: 13px;
  line-height: 1.75;
  color: var(--muted);
}

/* ---------- 复制链接 ---------- */
.page-about .about-copy {
  margin-top: clamp(20px, 3vw, 28px);
  display: flex;
  align-items: center;
  gap: 12px;
}

/* ---------- 团队 ---------- */
.page-about .team-grid {
  margin-top: clamp(32px, 5vw, 56px);
  display: grid;
  gap: clamp(32px, 4vw, 56px);
}

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

.page-about .team-ring svg {
  display: block;
  width: min(300px, 82%);
  height: auto;
  margin: 0 auto;
}

.page-about .team-ring__track {
  fill: none;
  stroke: var(--soft);
  stroke-width: 18;
}

.page-about .team-seg {
  fill: none;
  stroke-width: 18;
  transition: stroke-width var(--dur) var(--ease), opacity var(--dur) var(--ease);
}

.page-about .team-seg--data { stroke: var(--pitch); }
.page-about .team-seg--edit { stroke: var(--neon); }
.page-about .team-seg--build { stroke: var(--alert); }

.page-about .team-seg:hover {
  stroke-width: 26;
}

.page-about .team-ring__total {
  fill: var(--paper);
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 34px;
  text-anchor: middle;
}

.page-about .team-ring__unit {
  fill: var(--muted);
  font-size: 13px;
  letter-spacing: .2em;
  text-anchor: middle;
}

.page-about .team-ring__cap {
  margin-top: 14px;
  text-align: center;
  font-size: 13px;
  letter-spacing: .12em;
  color: var(--muted);
}

.page-about .team-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: clamp(20px, 3vw, 30px);
}

.page-about .team-role {
  display: grid;
  grid-template-columns: 4px minmax(0, 1fr);
  gap: clamp(16px, 2.4vw, 24px);
}

.page-about .team-role__bar {
  display: block;
  width: 4px;
  min-height: 68px;
  background: var(--pitch);
}

.page-about .team-role__bar--data { background: var(--pitch); }
.page-about .team-role__bar--edit { background: var(--neon); }
.page-about .team-role__bar--build { background: var(--alert); }

.page-about .team-role__name {
  margin: 0 0 8px;
}

.page-about .team-role__count {
  color: var(--pitch);
}

.page-about .team-role--edit .team-role__count { color: var(--neon); }
.page-about .team-role--build .team-role__count { color: var(--alert); }

.page-about .team-role__text {
  margin: 0;
  max-width: var(--about-measure);
  color: var(--muted);
}

/* ---------- 时间线 ---------- */
.page-about .timeline {
  margin-top: clamp(28px, 4vw, 44px);
}

.page-about .timeline__track {
  list-style: none;
  margin: 0;
  padding: 6px clamp(20px, 5vw, 48px) 22px;
  display: flex;
  gap: clamp(14px, 2vw, 22px);
  overflow-x: auto;
  scroll-snap-type: x mandatory;
  -webkit-overflow-scrolling: touch;
  scrollbar-color: var(--halo-strong) transparent;
}

.page-about .timeline__track::-webkit-scrollbar { height: 6px; }
.page-about .timeline__track::-webkit-scrollbar-thumb { background: var(--halo-strong); }
.page-about .timeline__track::-webkit-scrollbar-track { background: var(--soft); }

.page-about .timeline__node {
  flex: 0 0 min(78vw, 300px);
  display: flex;
  scroll-snap-align: start;
}

.page-about .timeline__card {
  width: 100%;
  padding: clamp(18px, 2.4vw, 24px);
  background: var(--panel);
  border: 1px solid var(--about-hair);
  border-top: 2px solid var(--gold);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - var(--cut)), calc(100% - var(--cut)) 100%, 0 100%);
  transition: border-color var(--dur) var(--ease);
}

.page-about .timeline__card:hover {
  border-color: var(--halo-strong);
}

.page-about .timeline__card summary {
  list-style: none;
  cursor: pointer;
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  gap: 6px 12px;
  align-items: center;
}

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

.page-about .timeline__mark {
  grid-column: 1;
  grid-row: 1 / span 2;
  width: 12px;
  height: 12px;
  background: var(--gold);
  transform: rotate(45deg);
}

.page-about .timeline__year {
  grid-column: 2;
  grid-row: 1;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-weight: 700;
  font-size: clamp(1.5rem, 4vw, 1.9rem);
  line-height: 1;
  color: var(--gold);
}

.page-about .timeline__name {
  grid-column: 2;
  grid-row: 2;
  font-size: 14px;
  letter-spacing: .05em;
  color: var(--paper);
}

.page-about .timeline__card summary::after {
  content: "+";
  grid-column: 3;
  grid-row: 1 / span 2;
  justify-self: end;
  align-self: center;
  font-family: var(--font-mono);
  font-size: 18px;
  color: var(--neon);
}

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

.page-about .timeline__text {
  margin: 14px 0 0;
  padding-top: 14px;
  border-top: 1px solid var(--about-hair);
  font-size: 14px;
  line-height: 1.75;
  color: var(--muted);
}

.page-about .timeline__hint {
  margin: 6px clamp(20px, 5vw, 48px) 0;
  font-size: 13px;
  letter-spacing: .06em;
  color: var(--muted);
}

/* ---------- 合作生态 ---------- */
.page-about .coop-grid {
  margin-top: clamp(32px, 5vw, 56px);
  display: grid;
  gap: var(--gap);
}

.page-about .coop-panel {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.page-about .coop-panel__num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-weight: 700;
  font-size: clamp(2.6rem, 8vw, 3.6rem);
  line-height: 1;
  color: var(--gold);
}

.page-about .coop-panel h3 {
  margin: 0;
}

.page-about .coop-panel p {
  margin: 0;
  color: var(--muted);
}

.page-about .coop-note {
  margin-top: var(--gap);
  display: grid;
  gap: 12px;
  justify-items: start;
}

.page-about .coop-note h3 {
  margin: 0;
}

.page-about .coop-note p {
  margin: 0;
  max-width: var(--about-measure);
  color: var(--muted);
}

/* ---------- 年度观察 ---------- */
.page-about .annual-grid {
  margin-top: clamp(32px, 5vw, 56px);
  display: grid;
  gap: clamp(28px, 4vw, 48px);
}

.page-about .annual-grid .about-shot {
  margin-top: 0;
}

.page-about .annual-body {
  display: grid;
  gap: 20px;
  justify-items: start;
  align-content: start;
}

.page-about .annual-body p {
  margin: 0;
  max-width: var(--about-measure);
  color: var(--muted);
}

.page-about .annual-toc {
  width: 100%;
  padding: 16px 18px;
  background: var(--panel);
  border: 1px solid var(--about-hair);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - var(--cut)), calc(100% - var(--cut)) 100%, 0 100%);
}

.page-about .annual-toc summary {
  list-style: none;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  font-size: 14px;
  letter-spacing: .08em;
  color: var(--paper);
}

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

.page-about .annual-toc summary::after {
  content: "展开";
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--neon);
}

.page-about .annual-toc[open] summary::after {
  content: "收起";
}

.page-about .annual-toc ul {
  margin: 14px 0 0;
  padding: 14px 0 0;
  list-style: none;
  display: grid;
  gap: 10px;
  border-top: 1px solid var(--about-hair);
}

.page-about .annual-toc li {
  position: relative;
  padding-left: 20px;
  font-size: 14px;
  line-height: 1.75;
  color: var(--muted);
}

.page-about .annual-toc li::before {
  content: "";
  position: absolute;
  left: 0;
  top: .72em;
  width: 8px;
  height: 8px;
  background: var(--gold);
  transform: rotate(45deg);
}

/* ---------- 继续阅读 ---------- */
.page-about .next-grid {
  display: grid;
  gap: var(--gap);
}

.page-about .next-card {
  display: grid;
  gap: 12px;
  padding: clamp(22px, 3vw, 32px);
  background: var(--panel);
  border: 1px solid var(--about-hair);
  text-decoration: none;
  color: var(--paper);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - var(--cut)), calc(100% - var(--cut)) 100%, 0 100%);
  transition: border-color var(--dur) var(--ease), transform var(--dur) var(--ease);
}

.page-about .next-card:hover,
.page-about .next-card:focus-visible {
  border-color: var(--halo-strong);
  transform: translateY(-3px);
}

.page-about .next-card h3 {
  margin: 0;
}

.page-about .next-card__go {
  font-family: var(--font-mono);
  font-size: 18px;
  color: var(--neon);
}

/* ---------- 响应式 ---------- */
@media (min-width: 720px) {
  .page-about .about-facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .about-fact {
    padding: 22px 20px 24px;
  }
}

@media (min-width: 820px) {
  .page-about .coop-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

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

@media (min-width: 860px) {
  .page-about .topic-line {
    grid-template-columns: 132px minmax(0, 1fr);
    column-gap: clamp(20px, 3vw, 40px);
    align-items: start;
  }

  .page-about .topic-line__when {
    grid-column: 1;
    grid-row: 1 / span 2;
    padding-top: .5em;
  }

  .page-about .topic-line__title {
    grid-column: 2;
    grid-row: 1;
  }

  .page-about .topic-line__text {
    grid-column: 2;
    grid-row: 2;
  }
}

@media (min-width: 900px) {
  .page-about .team-grid {
    grid-template-columns: minmax(0, 340px) minmax(0, 1fr);
    align-items: center;
  }

  .page-about .annual-grid {
    grid-template-columns: minmax(0, 400px) minmax(0, 1fr);
    align-items: start;
  }
}

@media (min-width: 1024px) {
  .page-about .timeline__track {
    padding-inline: clamp(48px, 6vw, 96px);
  }

  .page-about .timeline__hint {
    margin-inline: clamp(48px, 6vw, 96px);
  }
}

@media (min-width: 760px) {
  .page-about .next-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .team-seg,
  .page-about .timeline__card,
  .page-about .next-card {
    transition: none;
  }

  .page-about .next-card:hover,
  .page-about .next-card:focus-visible {
    transform: none;
  }
}
<<<END>>>