.page-about{
  --about-rule-paper: 1px solid rgba(19,26,34,.14);
  --about-rule-dark: 1px solid rgba(201,211,224,.22);
  background: var(--fog);
  color: var(--graphite);
  font-family: var(--font-body);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero{
  position: relative;
  overflow: hidden;
  padding: var(--sp-4) 0 var(--sp-5);
  color: var(--on-dark);
  background-color: var(--ink);
  background-image:
    linear-gradient(90deg, rgba(201,211,224,.06) 1px, transparent 1px),
    linear-gradient(180deg, rgba(201,211,224,.05) 1px, transparent 1px);
  background-size: 96px 96px, 96px 96px;
}
.page-about .about-hero .kicker{ color: var(--cyan); }
.page-about .about-hero__title{
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(32px, 7vw, 72px);
  line-height: 1.02;
  letter-spacing: -.02em;
  margin: var(--sp-2) 0 var(--sp-4);
  max-width: 15em;
  color: var(--on-dark);
}
.page-about .about-hero__grid{
  display: grid;
  gap: var(--sp-4);
}
.page-about .about-hero__body p{
  font-size: 16px;
  line-height: 1.75;
  margin: 0 0 var(--sp-2);
  color: var(--on-dark-soft);
}
.page-about .about-hero__body .lede{
  font-size: 18px;
  line-height: 1.65;
  color: var(--on-dark);
  margin-bottom: var(--sp-3);
}
.page-about .about-params{
  border-top: 1px solid rgba(201,211,224,.4);
  padding-top: var(--sp-2);
}
.page-about .about-params__title{
  margin: 0 0 var(--sp-1);
  font-size: 11px;
  letter-spacing: .18em;
  color: var(--on-dark-faint);
  font-weight: 500;
}
.page-about .about-params__list{ margin: 0; }
.page-about .about-params__item{
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: var(--sp-2);
  padding: 10px 0;
  border-bottom: 1px solid rgba(201,211,224,.16);
}
.page-about .about-params__item dt{
  margin: 0;
  font-size: 13px;
  color: var(--on-dark-soft);
}
.page-about .about-params__item dd{
  margin: 0;
  font-family: var(--font-mono);
  font-size: 15px;
  color: var(--on-dark);
  white-space: nowrap;
}

/* ---------- 通栏图 ---------- */
.page-about .about-band{
  margin: 0 auto;
  padding-top: var(--sp-4);
  padding-bottom: var(--sp-2);
}
.page-about .about-band .media{ margin: 0; }
.page-about .about-band img{
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  border-radius: var(--radius-panel);
}
.page-about .about-band .media__caption{
  display: block;
  margin-top: 12px;
  font-size: 13px;
  color: var(--on-paper-soft);
}

/* ---------- 章节索引 ---------- */
.page-about .about-toc{
  border-bottom: var(--about-rule-paper);
  border-top: var(--about-rule-paper);
}
.page-about .about-toc__shell{
  display: flex;
  align-items: center;
  gap: var(--sp-2);
  padding-top: 12px;
  padding-bottom: 12px;
  overflow-x: auto;
}
.page-about .about-toc__label{
  flex: none;
  font-size: 11px;
  letter-spacing: .18em;
  color: var(--on-paper-soft);
}
.page-about .about-toc ul{
  display: flex;
  gap: 6px;
  margin: 0;
  padding: 0;
  list-style: none;
}
.page-about .about-toc a{
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 12px;
  border: 1px solid transparent;
  border-radius: var(--radius-pill);
  font-size: 14px;
  color: var(--graphite);
  text-decoration: none;
  white-space: nowrap;
  transition: border-color var(--dur) var(--ease), color var(--dur) var(--ease), background-color var(--dur) var(--ease);
}
.page-about .about-toc a span{
  font-size: 11px;
  color: var(--on-paper-soft);
  letter-spacing: .06em;
}
.page-about .about-toc a:hover,
.page-about .about-toc a:focus-visible{
  border-color: var(--line-paper-strong);
  color: var(--ink);
  background: rgba(201,211,224,.24);
}
.page-about .about-toc a:hover span,
.page-about .about-toc a:focus-visible span{ color: var(--orange); }

/* ---------- 通用标题 ---------- */
.page-about .about-h2{
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(24px, 4.4vw, 40px);
  line-height: 1.14;
  letter-spacing: -.01em;
  margin: var(--sp-1) 0 var(--sp-2);
  color: var(--ink);
  max-width: 22em;
}
.page-about .about-h2--dark{ color: var(--on-dark); }
.page-about .section--dark .kicker{ color: var(--cyan); }
.page-about .section--dark .media__caption{ color: var(--on-dark-faint); }

/* ---------- 起点 ---------- */
.page-about .about-split{
  display: grid;
  gap: var(--sp-4);
}
.page-about .about-split__main p{
  font-size: 16px;
  line-height: 1.75;
  margin: 0 0 var(--sp-2);
  color: var(--graphite);
}
.page-about .about-split__main a{
  color: var(--ink);
  text-decoration: underline;
  text-decoration-color: var(--silver);
  text-underline-offset: 3px;
  transition: color var(--dur) var(--ease), text-decoration-color var(--dur) var(--ease);
}
.page-about .about-split__main a:hover{ color: var(--orange); text-decoration-color: var(--orange); }
.page-about .about-quote{
  position: relative;
  margin: 0 0 var(--sp-3);
  padding: var(--sp-3) var(--sp-3) var(--sp-2) 28px;
  border-radius: var(--radius-panel);
  background: var(--wine);
  color: var(--on-dark);
}
.page-about .about-quote::before{
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 3px;
  background: var(--orange);
  border-radius: var(--radius-panel) 0 0 var(--radius-panel);
}
.page-about .about-quote p{
  margin: 0 0 var(--sp-2);
  font-family: var(--font-serif);
  font-size: 18px;
  line-height: 1.6;
}
.page-about .about-quote footer{
  font-size: 11px;
  letter-spacing: .14em;
  color: var(--on-dark-soft);
}
.page-about .about-facts{
  margin: 0;
  padding: 0;
  list-style: none;
}
.page-about .about-facts li{
  display: flex;
  gap: 12px;
  align-items: baseline;
  padding: 12px 0;
  border-top: var(--about-rule-paper);
  font-size: 15px;
  line-height: 1.5;
  color: var(--graphite);
}
.page-about .about-facts li:last-child{ border-bottom: var(--about-rule-paper); }
.page-about .about-facts .mono{
  flex: none;
  min-width: 36px;
  font-size: 20px;
  color: var(--orange);
}

/* ---------- 方法 ---------- */
.page-about .about-method__lede{
  max-width: 46em;
  font-size: 16px;
  line-height: 1.75;
  color: var(--on-dark-soft);
  margin: 0 0 var(--sp-4);
}
.page-about .about-method__grid{
  display: grid;
  gap: var(--sp-3);
  margin-bottom: var(--sp-5);
}
.page-about .about-method__card{
  padding: var(--sp-2) 0;
  border-top: var(--about-rule-dark);
}
.page-about .about-method__no{
  display: block;
  margin-bottom: 10px;
  font-size: 11px;
  letter-spacing: .2em;
  color: var(--cyan);
}
.page-about .about-method__card h3{
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-size: 19px;
  font-weight: 700;
  color: var(--on-dark);
}
.page-about .about-method__card p{
  margin: 0;
  font-size: 15px;
  line-height: 1.72;
  color: var(--on-dark-soft);
}
.page-about .about-method__figure{ margin: 0 0 var(--sp-4); }
.page-about .about-method__figure .media{ margin: 0 0 12px; }
.page-about .about-method__figure img{
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
  border-radius: var(--radius-panel);
  border: 1px solid var(--line-dark);
}

.page-about .about-trials{
  display: grid;
  gap: 12px;
}
.page-about .about-trial{
  padding: var(--sp-2);
  border: 1px solid var(--line-dark);
  border-radius: var(--radius-panel);
  background: rgba(11,27,51,.28);
  transition: border-color var(--dur) var(--ease), background-color var(--dur) var(--ease);
}
.page-about .about-trial:hover{ border-color: var(--line-dark-strong); }
.page-about .about-trial[open]{
  border-color: var(--cyan);
  background: rgba(53,224,208,.07);
}
.page-about .about-trial summary{
  display: flex;
  align-items: baseline;
  gap: 10px;
  cursor: pointer;
  list-style: none;
  font-family: var(--font-display);
  font-size: 17px;
  font-weight: 700;
  color: var(--on-dark);
}
.page-about .about-trial summary::-webkit-details-marker{ display: none; }
.page-about .about-trial summary::after{
  content: "+";
  margin-left: auto;
  font-family: var(--font-mono);
  font-weight: 400;
  color: var(--cyan);
}
.page-about .about-trial[open] summary::after{ content: "−"; }
.page-about .about-trial__no{
  font-size: 11px;
  letter-spacing: .14em;
  color: var(--on-dark-faint);
}
.page-about .about-trial__body{
  padding-top: var(--sp-2);
  font-size: 14px;
  line-height: 1.72;
  color: var(--on-dark-soft);
}
.page-about .about-trial__body p{ margin: 0; }
.page-about .about-method__foot{
  margin: var(--sp-3) 0 0;
  font-size: 14px;
  line-height: 1.7;
  color: var(--on-dark-faint);
}
.page-about .about-method__foot a{
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(53,224,208,.4);
  transition: border-color var(--dur) var(--ease);
}
.page-about .about-method__foot a:hover{ border-bottom-color: var(--cyan); }

/* ---------- 维护 ---------- */
.page-about .about-maintain__lede{
  max-width: 44em;
  margin: 0 0 var(--sp-4);
  font-size: 16px;
  line-height: 1.75;
  color: var(--on-paper-soft);
}
.page-about .about-stats{
  display: grid;
  gap: var(--sp-2);
  margin-bottom: var(--sp-4);
  border-top: var(--about-rule-paper);
}
.page-about .about-stats__item{
  padding: var(--sp-3) 0 0;
  border-bottom: var(--about-rule-paper);
}
.page-about .about-stats__num{
  display: block;
  font-size: 40px;
  line-height: 1;
  color: var(--teal);
  margin-bottom: 10px;
}
.page-about .about-stats__label{
  display: block;
  padding-bottom: var(--sp-3);
  font-size: 14px;
  line-height: 1.65;
  color: var(--on-paper-soft);
}
.page-about .about-maintain__body p{
  font-size: 16px;
  line-height: 1.78;
  margin: 0 0 var(--sp-2);
  color: var(--graphite);
}
.page-about .about-maintain__body a{
  color: var(--ink);
  text-decoration: underline;
  text-decoration-color: var(--silver);
  text-underline-offset: 3px;
  transition: color var(--dur) var(--ease);
}
.page-about .about-maintain__body a:hover{ color: var(--orange); }

/* ---------- 团队 ---------- */
.page-about .about-team__lede{
  max-width: 40em;
  margin: 0 0 var(--sp-4);
  font-size: 16px;
  line-height: 1.75;
  color: var(--on-dark-soft);
}
.page-about .about-team__grid{
  display: grid;
  gap: 12px;
}
.page-about .about-team__card{
  padding: var(--sp-3);
  border: 1px solid var(--line-dark);
  border-radius: var(--radius-panel);
  background: rgba(11,27,51,.3);
  transition: transform var(--dur) var(--ease), box-shadow var(--dur) var(--ease), border-color var(--dur) var(--ease);
}
.page-about .about-team__card:hover{
  transform: translateY(-2px);
  box-shadow: var(--shadow-2);
  border-color: var(--line-dark-strong);
}
.page-about .about-team__card--lead{
  border-color: rgba(53,224,208,.42);
  background: linear-gradient(158deg, rgba(53,224,208,.14), rgba(11,27,51,.42));
}
.page-about .about-team__num{
  margin: 0 0 10px;
  font-size: 38px;
  line-height: 1;
  color: var(--cyan);
}
.page-about .about-team__card h3{
  margin: 0 0 10px;
  font-family: var(--font-display);
  font-size: 18px;
  font-weight: 700;
  color: var(--on-dark);
}
.page-about .about-team__card p{
  margin: 0;
  font-size: 14.5px;
  line-height: 1.72;
  color: var(--on-dark-soft);
}
.page-about .about-team__foot{
  margin: var(--sp-3) 0 0;
  padding-top: var(--sp-2);
  border-top: var(--about-rule-dark);
  font-size: 14px;
  line-height: 1.7;
  color: var(--on-dark-faint);
}

/* ---------- 版本 ---------- */
.page-about .about-versions__figure{
  margin: 0 0 var(--sp-4);
}
.page-about .about-versions__figure .media{ margin: 0 0 12px; }
.page-about .about-versions__figure img{
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
  border-radius: var(--radius-panel);
  border: 1px solid var(--line-dark);
}
.page-about .about-versions__intro{
  max-width: 46em;
  margin: 0 0 var(--sp-4);
  font-size: 16px;
  line-height: 1.75;
  color: var(--on-dark-soft);
}
.page-about .about-track{
  overflow-x: auto;
  padding-bottom: var(--sp-2);
}
.page-about .about-track__nodes{
  position: relative;
  display: flex;
  align-items: flex-start;
  gap: 10px;
  min-width: 900px;
  padding-top: 34px;
}
.page-about .about-track__nodes::before{
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  top: 11px;
  height: 1px;
  background: var(--line-dark-strong);
}
.page-about .track-node{
  position: relative;
  flex: 1 1 0;
  min-width: 0;
  padding: 0 4px;
  outline-offset: 6px;
}
.page-about .track-node__dot{
  position: absolute;
  top: -28px;
  left: 4px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--silver);
  transition: background-color var(--dur) var(--ease), box-shadow var(--dur) var(--ease);
}
.page-about .track-node--lg .track-node__dot{
  width: 15px;
  height: 15px;
  top: -31px;
}
.page-about .track-node--now .track-node__dot{
  background: var(--orange);
  box-shadow: 0 0 0 4px rgba(255,106,43,.2);
}
.page-about .track-node:hover .track-node__dot,
.page-about .track-node:focus .track-node__dot{
  background: var(--cyan);
  box-shadow: 0 0 0 4px rgba(53,224,208,.18);
}
.page-about .track-node--now:hover .track-node__dot,
.page-about .track-node--now:focus .track-node__dot{ background: var(--orange); }
.page-about .track-node__ver{
  display: block;
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--cyan);
}
.page-about .track-node__name{
  display: block;
  margin: 4px 0 2px;
  font-family: var(--font-display);
  font-size: 15px;
  font-weight: 700;
  line-height: 1.3;
  color: var(--on-dark);
}
.page-about .track-node__when{
  display: block;
  font-size: 11px;
  letter-spacing: .06em;
  color: var(--on-dark-faint);
}
.page-about .track-node__pop{
  display: none;
  margin-top: 10px;
  padding-top: 10px;
  border-top: 1px solid rgba(201,211,224,.2);
  font-size: 12.5px;
  line-height: 1.65;
  color: var(--on-dark-soft);
}
.page-about .track-node:hover .track-node__pop,
.page-about .track-node:focus .track-node__pop,
.page-about .track-node:focus-within .track-node__pop{ display: block; }

/* ---------- 结尾 ---------- */
.page-about .about-cta__inner{
  display: grid;
  gap: var(--sp-3);
  align-items: end;
}
.page-about .about-cta__text p{
  max-width: 42em;
  margin: 0;
  font-size: 16px;
  line-height: 1.75;
  color: var(--on-dark-soft);
}
.page-about .about-cta__actions{
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

/* ---------- 断点 ---------- */
@media (min-width: 720px){
  .page-about .about-stats{
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 0;
  }
  .page-about .about-stats__item{
    padding: var(--sp-3) var(--sp-3) 0 0;
    border-bottom: 0;
    border-right: var(--about-rule-paper);
  }
  .page-about .about-stats__item:last-child{ border-right: 0; }
  .page-about .about-team__grid{ grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .page-about .about-team__card--lead{ grid-column: 1 / -1; }
}

@media (min-width: 900px){
  .page-about .about-hero{ padding-top: var(--sp-5); }
  .page-about .about-hero__grid{
    grid-template-columns: minmax(0, 1fr) minmax(0, 320px);
    gap: 88px;
    align-items: start;
  }
  .page-about .about-split{
    grid-template-columns: minmax(0, 1fr) minmax(0, 348px);
    gap: 88px;
    align-items: start;
  }
  .page-about .about-split__side{ position: sticky; top: 96px; }
  .page-about .about-method__grid{
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 0;
    border-top: var(--about-rule-dark);
  }
  .page-about .about-method__card{
    border-top: 0;
    border-right: var(--about-rule-dark);
    padding: var(--sp-3) var(--sp-3) var(--sp-3) 0;
  }
  .page-about .about-method__card:last-child{
    border-right: 0;
    padding-right: 0;
  }
  .page-about .about-method__card + .about-method__card{ padding-left: var(--sp-3); }
  .page-about .about-trials{ grid-template-columns: repeat(3, minmax(0, 1fr)); }
  .page-about .about-team__grid{ grid-template-columns: 1.15fr 1fr 1fr; gap: var(--sp-3); align-items: stretch; }
  .page-about .about-team__card--lead{ grid-column: auto; }
  .page-about .about-cta__inner{
    grid-template-columns: minmax(0, 1fr) auto;
    gap: var(--sp-4);
  }
  .page-about .about-cta__actions{ justify-content: flex-end; }
}

@media (hover: none){
  .page-about .track-node__pop{ display: block; }
}

@media (prefers-reduced-motion: reduce){
  .page-about .about-team__card:hover{ transform: none; }
  .page-about .about-toc a,
  .page-about .track-node__dot{ transition: none; }
}