.page-about {
  --about-read: 68ch;
  background: var(--ink);
  color: var(--mist);
}

/* ---------- 面包屑 ---------- */
.page-about .about-trail {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--rock);
  margin-bottom: clamp(22px, 4vw, 40px);
}

.page-about .about-trail a {
  color: var(--mist);
  text-decoration: none;
  border-bottom: 1px solid var(--line);
  transition: color 180ms var(--ease), border-color 180ms var(--ease);
}

.page-about .about-trail a:hover {
  color: var(--cyan);
  border-color: var(--cyan);
}

.page-about .about-trail__sep {
  color: var(--rock);
}

.page-about .about-trail__here {
  color: var(--paper);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  padding-block: clamp(20px, 4vw, 44px) clamp(34px, 6vw, 72px);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image:
    linear-gradient(to right, rgba(108, 120, 133, 0.1) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(108, 120, 133, 0.1) 1px, transparent 1px);
  background-size: 34px 34px;
  -webkit-mask-image: radial-gradient(circle at 74% 18%, #000 0%, transparent 72%);
  mask-image: radial-gradient(circle at 74% 18%, #000 0%, transparent 72%);
}

.page-about .about-hero > .container {
  position: relative;
  z-index: 1;
}

.page-about .about-hero__title {
  font-size: clamp(28px, 5.2vw, 52px);
  line-height: 1.18;
  letter-spacing: 0.02em;
  color: var(--paper);
  max-width: 22ch;
  margin: 14px 0 20px;
}

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

.page-about .about-facts {
  list-style: none;
  margin: clamp(26px, 4vw, 44px) 0 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--line-soft);
  border: 1px solid var(--line-soft);
  border-radius: var(--radius-md);
  overflow: hidden;
}

.page-about .about-fact {
  background: var(--panel-deep);
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: 8px 16px;
  padding: 14px 16px;
}

.page-about .about-fact__label {
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--rock);
}

.page-about .about-fact__value {
  font-family: var(--font-mono);
  font-size: 17px;
  color: var(--paper);
  white-space: nowrap;
}

.page-about .about-fact:first-child .about-fact__value {
  color: var(--cyan);
}

/* ---------- 通用小节题头 ---------- */
.page-about .about-head {
  max-width: 76ch;
}

.page-about .about-head .module-title {
  color: var(--paper);
  margin: 12px 0 12px;
}

.page-about .about-head .scope {
  margin: 0;
}

.page-about .about-sub {
  font-size: 18px;
  letter-spacing: 0.06em;
  color: var(--paper);
  margin: 0 0 8px;
}

/* ---------- 站点定位 ---------- */
.page-about .about-scope__grid {
  display: grid;
  gap: 14px;
  margin-top: clamp(26px, 4vw, 40px);
}

.page-about .scope-col {
  background: var(--panel-deep);
  border: 1px solid var(--line-soft);
  border-radius: var(--radius-md);
  padding: 20px 18px 22px;
  position: relative;
  border-top: 2px solid var(--moss);
}

.page-about .scope-col__idx {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--rock);
  margin: 0 0 10px;
}

.page-about .scope-col__title {
  font-size: 17px;
  letter-spacing: 0.05em;
  color: var(--paper);
  margin: 0 0 10px;
  line-height: 1.5;
}

.page-about .scope-col__text {
  margin: 0;
  font-size: 15px;
  line-height: 1.75;
  color: var(--mist);
}

/* ---------- 年表 ---------- */
.page-about .epoch-list {
  list-style: none;
  margin: clamp(28px, 4vw, 46px) 0 0;
  padding: 0;
}

.page-about .epoch-list--tail {
  margin-top: clamp(26px, 4vw, 42px);
}

.page-about .epoch {
  position: relative;
  padding: 0 0 26px 24px;
  border-left: 1px solid var(--line);
  margin-bottom: 8px;
}

.page-about .epoch:last-child {
  padding-bottom: 8px;
}

.page-about .epoch::before {
  content: "";
  position: absolute;
  left: -5px;
  top: 12px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--clay);
  transition: background 200ms var(--ease), box-shadow 200ms var(--ease);
}

.page-about .epoch--current::before,
.page-about .epoch:target::before {
  background: var(--cyan);
  box-shadow: 0 0 0 4px rgba(63, 224, 206, 0.18);
}

.page-about .epoch__year {
  font-family: var(--font-mono);
  font-size: 22px;
  letter-spacing: -0.01em;
  color: var(--clay);
  margin-bottom: 10px;
}

.page-about .epoch--current .epoch__year,
.page-about .epoch:target .epoch__year {
  color: var(--cyan);
}

.page-about .epoch__body {
  background: var(--paper);
  color: var(--on-paper);
  border-radius: var(--radius-md);
  padding: 20px 18px 22px;
}

.page-about .epoch:target .epoch__body {
  outline: 2px solid var(--focus);
  outline-offset: 3px;
}

.page-about .epoch__title {
  font-size: 19px;
  letter-spacing: 0.04em;
  color: var(--on-paper);
  margin: 0 0 12px;
  line-height: 1.45;
}

.page-about .epoch__body p {
  margin: 0 0 16px;
  font-size: 15px;
  line-height: 1.78;
  max-width: var(--about-read);
}

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

.page-about .epoch__body .scope {
  color: var(--on-paper-soft);
  font-size: 13px;
}

.page-about .epoch__body a {
  color: var(--clay);
  text-decoration: none;
  border-bottom: 1px solid rgba(180, 102, 62, 0.5);
}

.page-about .epoch__body a:hover {
  color: var(--orange);
  border-color: var(--orange);
}

.page-about .epoch__media {
  margin: 6px 0 16px;
}

.page-about .epoch__body .media__caption {
  color: var(--on-paper-soft);
}

/* ---------- 横向主题带 ---------- */
.page-about .about-rail {
  margin: clamp(24px, 4vw, 38px) 0 0;
  padding-bottom: 10px;
  gap: 12px;
}

.page-about .about-snap {
  flex: 0 0 200px;
  background: var(--panel-raised);
  border: 1px solid var(--line-soft);
  border-radius: var(--radius-md);
  padding: 16px 16px 18px;
}

.page-about .about-snap__year {
  font-family: var(--font-mono);
  font-size: 15px;
  color: var(--cyan);
  margin: 0 0 12px;
}

.page-about .about-snap__key {
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--rock);
  margin: 0 0 4px;
}

.page-about .about-snap__val {
  font-family: var(--font-mono);
  font-size: 22px;
  color: var(--paper);
  margin: 0;
  white-space: nowrap;
}

/* ---------- 团队 ---------- */
.page-about .about-team__grid {
  display: grid;
  gap: clamp(24px, 4vw, 40px);
  margin-top: clamp(24px, 4vw, 40px);
  align-items: end;
}

.page-about .about-bignum {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(72px, 17vw, 168px);
  line-height: 0.9;
  letter-spacing: -0.02em;
  color: var(--paper);
  margin: 0 0 12px;
}

.page-about .about-bignum__unit {
  font-size: 0.26em;
  letter-spacing: 0.06em;
  color: var(--cyan);
  margin-left: 0.12em;
}

.page-about .about-team__figure .scope {
  margin: 0;
  max-width: 42ch;
}

.page-about .role-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 14px;
}

.page-about .role {
  display: grid;
  grid-template-columns: 1fr auto;
  grid-template-areas:
    "name value"
    "track track";
  gap: 8px 14px;
  align-items: center;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--line-soft);
}

.page-about .role:last-child {
  border-bottom: none;
  padding-bottom: 0;
}

.page-about .role__name {
  grid-area: name;
  font-size: 15px;
  letter-spacing: 0.04em;
  color: var(--paper);
}

.page-about .role__value {
  grid-area: value;
  font-family: var(--font-mono);
  font-size: 18px;
  color: var(--cyan);
}

.page-about .role__track {
  grid-area: track;
  display: block;
  height: 4px;
  border-radius: 2px;
  background: rgba(108, 120, 133, 0.24);
  overflow: hidden;
}

.page-about .role__bar {
  display: block;
  height: 100%;
  border-radius: 2px;
  background: var(--moss);
}

.page-about .role--ops .role__bar { width: 100%; }
.page-about .role--survey .role__bar { width: 33%; }
.page-about .role--proof .role__bar { width: 28%; }
.page-about .role--product .role__bar { width: 39%; }

/* ---------- 流程路径图 ---------- */
.page-about .about-flow {
  margin-top: clamp(30px, 5vw, 52px);
  padding-top: clamp(20px, 3vw, 30px);
  border-top: 1px solid var(--line-soft);
}

.page-about .about-flow__scroll {
  margin-top: 18px;
  overflow-x: auto;
  padding-bottom: 6px;
}

.page-about .flowmap {
  display: block;
  width: 100%;
  min-width: 620px;
  height: auto;
}

.page-about .flowmap__links {
  fill: var(--rock);
  stroke: var(--line);
  stroke-width: 1;
}

.page-about .flowmap__node rect {
  fill: var(--panel-deep);
  stroke: var(--line);
  stroke-width: 1;
  transition: stroke 200ms var(--ease), fill 200ms var(--ease);
}

.page-about .flowmap__node:hover rect {
  stroke: var(--cyan);
  fill: var(--panel-raised);
}

.page-about .flowmap__step {
  font-family: var(--font-sans);
  font-size: 17px;
  font-weight: 700;
  letter-spacing: 0.06em;
  fill: var(--paper);
}

.page-about .flowmap__time {
  font-family: var(--font-mono);
  font-size: 12.5px;
  fill: var(--mist);
}

.page-about .about-team__media {
  margin: clamp(28px, 4vw, 44px) 0 0;
}

/* ---------- 合作生态 ---------- */
.page-about .about-partners__grid {
  display: grid;
  gap: clamp(24px, 4vw, 44px);
  align-items: start;
}

.page-about .about-partners__text p {
  font-size: 15px;
  line-height: 1.78;
  max-width: var(--about-read);
  margin: 0 0 16px;
}

.page-about .about-partner-list {
  list-style: none;
  margin: 22px 0;
  padding: 0;
  display: grid;
  gap: 12px;
}

.page-about .about-partner {
  display: flex;
  align-items: baseline;
  gap: 14px;
  padding-bottom: 11px;
  border-bottom: 1px solid var(--line-soft);
}

.page-about .about-partner:last-child {
  border-bottom: none;
  padding-bottom: 0;
}

.page-about .about-partner__num {
  font-family: var(--font-mono);
  font-size: 26px;
  color: var(--orange);
  min-width: 2.4ch;
  white-space: nowrap;
}

.page-about .about-partner__name {
  font-size: 14px;
  line-height: 1.7;
  color: var(--mist);
}

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

/* ---------- 公开记录 ---------- */
.page-about .record-list {
  list-style: none;
  margin: clamp(24px, 4vw, 40px) 0 0;
  padding: 0;
  border-top: 1px solid var(--line);
}

.page-about .record {
  display: grid;
  gap: 6px;
  padding: 16px 0;
  border-bottom: 1px solid var(--line-soft);
}

.page-about .record__key {
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--rock);
}

.page-about .record__val {
  font-size: 15px;
  line-height: 1.7;
  color: var(--paper);
}

/* ---------- 呼吸留白 ---------- */
.page-about .about-breath {
  height: clamp(46px, 9vw, 110px);
}

/* ---------- 版本对照 ---------- */
.page-about .about-versions__caption {
  text-align: left;
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--rock);
  padding: 0 0 12px;
}

.page-about .about-versions tbody th[scope="row"] {
  color: var(--mist);
  font-weight: 400;
  white-space: nowrap;
}

.page-about .about-versions thead th:last-child,
.page-about .about-versions tbody td:last-child {
  color: var(--paper);
}

.page-about .about-versions-block .note {
  margin-top: 20px;
  max-width: 78ch;
}

.page-about .about-versions-block .note a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(63, 224, 206, 0.4);
}

.page-about .about-versions-block .note a:hover {
  color: var(--focus);
  border-color: var(--focus);
}

/* ---------- 交互与可访问性 ---------- */
.page-about .rail:focus-visible {
  outline: 2px solid var(--focus);
  outline-offset: 3px;
}

.page-about [data-reveal] {
  opacity: 0;
  transform: translateY(8px);
  transition: opacity 220ms var(--ease), transform 220ms var(--ease);
  transition-delay: var(--stagger, 0ms);
}

.page-about [data-reveal][data-shown] {
  opacity: 1;
  transform: none;
}

/* ---------- 响应式 ---------- */
@media (min-width: 620px) {
  .page-about .about-facts {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .about-fact {
    flex-direction: column;
    align-items: flex-start;
    justify-content: flex-start;
    gap: 8px;
    padding: 16px 18px 18px;
  }

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

  .page-about .record {
    grid-template-columns: 172px minmax(0, 1fr);
    gap: 20px;
    align-items: baseline;
  }

  .page-about .record__key {
    text-align: right;
  }

  .page-about .about-team__grid {
    grid-template-columns: minmax(0, 1fr) minmax(280px, 1fr);
  }
}

@media (min-width: 900px) {
  .page-about .epoch {
    display: grid;
    grid-template-columns: 132px minmax(0, 1fr);
    gap: clamp(20px, 3vw, 38px);
    padding-left: 34px;
    padding-bottom: 34px;
  }

  .page-about .epoch::before {
    top: 14px;
  }

  .page-about .epoch__year {
    font-size: 24px;
    margin-bottom: 0;
    padding-top: 12px;
    text-align: right;
  }

  .page-about .epoch__body {
    padding: clamp(22px, 2.6vw, 32px) clamp(22px, 2.8vw, 34px);
  }

  .page-about .about-partners__grid {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, 1fr);
    align-items: center;
  }

  .page-about .about-team__media {
    max-width: 640px;
  }
}

@media (min-width: 1180px) {
  .page-about .about-scope__grid {
    gap: 20px;
  }

  .page-about .about-scope__grid .scope-col:nth-child(2) {
    transform: translateY(12px);
  }

  .page-about .about-scope__grid .scope-col:nth-child(3) {
    transform: translateY(24px);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about [data-reveal],
  .page-about [data-reveal][data-shown] {
    opacity: 1;
    transform: none;
    transition: none;
  }

  .page-about .epoch::before,
  .page-about .flowmap__node rect,
  .page-about .about-trail a {
    transition: none;
  }

  .page-about .about-flow__scroll,
  .page-about .about-rail {
    scroll-behavior: auto;
  }
}

.page-about {
  --stagger: 0.3s;
}