.page-about{
  --about-rule:rgba(159,184,174,.16);
  --about-rule-soft:rgba(159,184,174,.09);
  display:block;
  background:var(--night);
  color:var(--fog);
}

/* 顶部定位条 */
.page-about .about-topbar{
  background:var(--abyss);
  padding:clamp(1rem,2.4vw,1.6rem) 0 clamp(.4rem,1.2vw,.8rem);
}

/* 首屏 */
.page-about .about-hero{
  position:relative;
  overflow:hidden;
  background:var(--abyss);
  border-bottom:1px solid var(--about-rule);
  padding:clamp(1.4rem,3.6vw,2.6rem) 0 clamp(2.4rem,5vw,4rem);
}
.page-about .about-hero::before{
  content:"";
  position:absolute;
  inset:0;
  background-image:
    linear-gradient(var(--grid-line) 1px,transparent 1px),
    linear-gradient(90deg,var(--grid-line) 1px,transparent 1px);
  background-size:56px 56px;
  pointer-events:none;
}
.page-about .about-hero::after{
  content:"";
  position:absolute;
  top:-20%;
  right:-10%;
  width:min(48vw,540px);
  height:min(48vw,540px);
  background:radial-gradient(circle at center,rgba(53,224,176,.15),transparent 68%);
  pointer-events:none;
}
.page-about .about-hero .shell{
  position:relative;
  z-index:1;
}
.page-about .about-hero__rail{
  display:flex;
  flex-wrap:wrap;
  gap:.6rem 1.4rem;
  align-items:center;
  justify-content:space-between;
  padding-bottom:1.3rem;
  border-bottom:1px solid var(--about-rule-soft);
}
.page-about .about-hero__since{
  font-size:.74rem;
  letter-spacing:.22em;
  color:var(--sage);
}
.page-about .about-hero__title{
  margin:clamp(1.3rem,3vw,2.1rem) 0 0;
  padding-right:.4em;
  font-family:var(--font-display);
  font-weight:900;
  font-size:clamp(1.9rem,6.2vw,4.4rem);
  line-height:1.06;
  letter-spacing:-.015em;
  color:var(--fog);
  transform:var(--tilt);
  transform-origin:left center;
}
.page-about .about-hero__title span{
  color:var(--cyan);
}
.page-about .about-hero__body{
  display:grid;
  gap:clamp(1.6rem,3vw,2.4rem);
  margin-top:clamp(1.6rem,3.6vw,2.6rem);
}
@media (min-width:64rem){
  .page-about .about-hero__body{
    grid-template-columns:minmax(0,1.15fr) minmax(0,1fr);
    align-items:end;
    gap:clamp(2rem,4vw,3.6rem);
  }
}
.page-about .about-hero__lead{
  margin:0;
  max-width:34em;
  font-size:clamp(1rem,2.1vw,1.2rem);
  line-height:1.88;
  color:var(--sage);
}

/* 首屏数据条 */
.page-about .about-stats{
  display:grid;
  grid-template-columns:repeat(2,minmax(0,1fr));
  gap:1px;
  margin:0;
  background:var(--about-rule-soft);
  border:1px solid var(--about-rule);
}
@media (min-width:36rem){
  .page-about .about-stats{
    grid-template-columns:repeat(4,minmax(0,1fr));
  }
}
.page-about .about-stats > div{
  background:var(--abyss);
  padding:clamp(.85rem,2vw,1.15rem);
  min-width:0;
}
.page-about .about-stats dt{
  font-size:.72rem;
  letter-spacing:.1em;
  color:var(--sage);
}
.page-about .about-stats dd{
  margin:.5rem 0 0;
  font-family:var(--font-mono);
  font-size:clamp(1.4rem,3.4vw,1.95rem);
  line-height:1;
  color:var(--cyan);
}

/* 主栏 + 边注布局 */
.page-about .about-layout{
  display:grid;
  gap:clamp(2.2rem,5vw,3.4rem);
  padding:clamp(2.6rem,6vw,4.4rem) 0 clamp(3.4rem,7vw,5.6rem);
}
@media (min-width:64rem){
  .page-about .about-layout{
    grid-template-columns:minmax(0,1fr) 292px;
    gap:clamp(3rem,6vw,5rem);
    align-items:start;
  }
}
.page-about .about-main{
  min-width:0;
}

/* 侧栏 */
.page-about .about-aside{
  display:grid;
  gap:1.6rem;
  align-content:start;
  min-width:0;
}
@media (max-width:63.9rem){
  .page-about .about-aside{
    order:-1;
  }
}
@media (min-width:64rem){
  .page-about .about-aside{
    position:sticky;
    top:6.5rem;
  }
}
.page-about .about-aside .chapter-nav{
  border-top:1px solid var(--line-cyan);
  padding-top:1rem;
  min-width:0;
}
.page-about .about-aside .chapter-nav > .label{
  display:block;
}
.page-about .about-aside .chapter-nav ul{
  list-style:none;
  margin:.9rem 0 0;
  padding:0;
}
.page-about .about-aside .chapter-nav__link{
  display:flex;
  gap:.7rem;
  align-items:baseline;
  padding:.6rem .1rem;
  font-size:.88rem;
  color:var(--sage);
  text-decoration:none;
  border-bottom:1px solid var(--about-rule-soft);
  transition:color .18s var(--ease),border-color .18s var(--ease);
}
.page-about .about-aside .chapter-nav__link:hover{
  color:var(--fog);
}
.page-about .about-aside .chapter-nav__link[aria-current="true"]{
  color:var(--cyan);
  border-bottom-color:var(--line-cyan);
}
.page-about .about-aside .chapter-nav__num{
  flex:0 0 auto;
  font-family:var(--font-mono);
  font-size:.72rem;
  letter-spacing:.06em;
  color:var(--cyan);
  opacity:.8;
}
@media (max-width:63.9rem){
  .page-about .about-aside .chapter-nav ul{
    display:flex;
    flex-wrap:nowrap;
    gap:.9rem;
    overflow-x:auto;
    padding-bottom:.5rem;
    -webkit-overflow-scrolling:touch;
  }
  .page-about .about-aside .chapter-nav ul > li{
    flex:0 0 auto;
  }
  .page-about .about-aside .chapter-nav__link{
    border-bottom:0;
    padding:.35rem .6rem;
    border:1px solid var(--about-rule);
    white-space:nowrap;
  }
}
.page-about .about-aside__note{
  border:1px solid var(--about-rule);
  background:rgba(14,58,44,.55);
  padding:1rem 1.05rem;
}
.page-about .about-aside__note .label{
  display:block;
  margin-bottom:.6rem;
}
.page-about .about-aside__note p{
  margin:0;
  font-size:.85rem;
  line-height:1.78;
  color:var(--sage);
}
.page-about .about-aside__note strong{
  font-family:var(--font-mono);
  font-weight:500;
  color:var(--amber);
}

/* 章节 */
.page-about .about-chapter{
  margin-top:clamp(3rem,6vw,4.6rem);
  padding-top:clamp(3rem,6vw,4.6rem);
  border-top:1px solid var(--about-rule);
}
.page-about .about-chapter:first-child{
  margin-top:0;
  padding-top:0;
  border-top:0;
}
.page-about .about-chapter__head{
  display:grid;
  gap:.7rem;
}
.page-about .about-chapter__title{
  margin:0;
  font-family:var(--font-display);
  font-weight:800;
  font-size:clamp(1.4rem,3.4vw,2.1rem);
  line-height:1.24;
  letter-spacing:-.01em;
  color:var(--fog);
}
.page-about .about-quote{
  margin:1.5rem 0 0;
  padding:.2rem 0 .2rem 1.2rem;
  border-left:2px solid var(--cyan);
  font-family:var(--font-serif);
  font-size:clamp(1rem,2.2vw,1.24rem);
  line-height:1.9;
  color:var(--fog);
}

/* 正文 */
.page-about .prose{
  max-width:42em;
  margin-top:1.4rem;
  font-size:1rem;
  line-height:1.85;
  color:var(--sage);
}
.page-about .prose p{
  margin:0 0 1.05rem;
}
.page-about .prose p:last-child{
  margin-bottom:0;
}
.page-about .prose strong{
  color:var(--fog);
  font-weight:600;
}
.page-about .prose a{
  color:var(--blue);
  text-decoration:none;
  border-bottom:1px solid rgba(59,155,255,.42);
}
.page-about .prose a:hover{
  border-bottom-color:var(--blue);
}

/* 三件事 / 三条线 */
.page-about .about-list{
  list-style:none;
  margin:1.6rem 0 0;
  padding:0;
  display:grid;
  gap:1px;
  background:var(--about-rule-soft);
  border:1px solid var(--about-rule);
}
.page-about .about-list > li{
  background:rgba(14,58,44,.62);
  padding:clamp(1rem,2.4vw,1.35rem);
}
.page-about .about-list__title{
  margin:0 0 .5rem;
  font-size:1.02rem;
  font-weight:700;
  letter-spacing:.01em;
  color:var(--cyan);
}
.page-about .about-list > li p{
  margin:0;
  font-size:.94rem;
  line-height:1.8;
  color:var(--sage);
}

/* 12 项指标 */
.page-about .about-metrics{
  list-style:none;
  margin:1.6rem 0 0;
  padding:0;
  display:grid;
  grid-template-columns:minmax(0,1fr);
  gap:1px;
  background:var(--about-rule-soft);
  border:1px solid var(--about-rule);
}
@media (min-width:46rem){
  .page-about .about-metrics{
    grid-template-columns:repeat(2,minmax(0,1fr));
  }
}
.page-about .about-metrics > li{
  display:flex;
  gap:.75rem;
  align-items:baseline;
  background:var(--panel);
  padding:.82rem 1rem;
  font-size:.94rem;
  color:var(--fog);
}
.page-about .about-metrics__num{
  flex:0 0 auto;
  font-family:var(--font-mono);
  font-size:.72rem;
  letter-spacing:.06em;
  color:var(--cyan);
}
.page-about .about-metrics > li.is-key{
  background:linear-gradient(90deg,rgba(255,122,47,.2),rgba(255,122,47,.04));
  box-shadow:inset 2px 0 0 var(--orange);
}
.page-about .about-metrics > li.is-key .about-metrics__num{
  color:var(--orange);
}

/* 术语悬停卡 */
.page-about .term{
  position:relative;
  color:var(--amber);
  border-bottom:1px dashed rgba(255,200,87,.5);
  cursor:help;
  outline:none;
}
.page-about .term:focus-visible{
  outline:1px solid var(--amber);
  outline-offset:3px;
}
.page-about .term__card{
  position:absolute;
  left:0;
  bottom:calc(100% + 10px);
  width:min(268px,72vw);
  padding:.75rem .85rem;
  background:var(--abyss);
  border:1px solid var(--line-cyan);
  font-family:var(--font-display);
  font-size:.8rem;
  line-height:1.7;
  color:var(--sage);
  opacity:0;
  visibility:hidden;
  transition:opacity .2s var(--ease);
  z-index:8;
  pointer-events:none;
}
.page-about .term:hover .term__card,
.page-about .term:focus .term__card,
.page-about .term:focus-within .term__card{
  opacity:1;
  visibility:visible;
}

/* 五步流程图 */
.page-about .about-flow-wrap{
  margin-top:1.7rem;
  padding:1.1rem;
  overflow-x:auto;
  background:var(--abyss);
  border:1px solid var(--about-rule);
  -webkit-overflow-scrolling:touch;
}
.page-about .about-flow{
  display:block;
  width:100%;
  min-width:720px;
  height:auto;
}
.page-about .about-flow rect{
  fill:rgba(20,73,58,.55);
  stroke:var(--line-cyan);
  stroke-width:1;
}
.page-about .about-flow .is-last rect{
  fill:rgba(255,122,47,.16);
  stroke:rgba(255,122,47,.6);
}
.page-about .about-flow .flow-num{
  font-family:var(--font-mono);
  font-size:14px;
  letter-spacing:2px;
  fill:var(--cyan);
}
.page-about .about-flow .is-last .flow-num{
  fill:var(--orange);
}
.page-about .about-flow .flow-name{
  font-family:var(--font-display);
  font-size:21px;
  font-weight:700;
  fill:var(--fog);
}
.page-about .about-flow .flow-link{
  stroke:var(--line-cyan);
  stroke-width:1;
}

/* 五步说明 */
.page-about .about-steps{
  list-style:none;
  counter-reset:step;
  margin:1.7rem 0 0;
  padding:0;
}
.page-about .about-steps > li{
  position:relative;
  padding:.95rem 0 .95rem 2.6rem;
  border-top:1px solid var(--about-rule-soft);
}
.page-about .about-steps > li:last-child{
  border-bottom:1px solid var(--about-rule-soft);
}
.page-about .about-steps > li::before{
  counter-increment:step;
  content:counter(step,decimal-leading-zero);
  position:absolute;
  left:0;
  top:1rem;
  font-family:var(--font-mono);
  font-size:.78rem;
  letter-spacing:.06em;
  color:var(--cyan);
}
.page-about .about-steps__title{
  margin:0 0 .35rem;
  font-size:1rem;
  font-weight:700;
  color:var(--fog);
}
.page-about .about-steps > li p{
  margin:0;
  font-size:.93rem;
  line-height:1.8;
  color:var(--sage);
}
.page-about .about-duration{
  display:inline-flex;
  align-items:baseline;
  gap:.5rem;
  margin:1.6rem 0 0;
  padding:.6rem 1rem;
  border:1px solid var(--line-cyan);
  background:rgba(53,224,176,.07);
  font-size:.9rem;
  color:var(--sage);
}
.page-about .about-duration .mono{
  font-size:1.35rem;
  color:var(--cyan);
}

/* 配图 */
.page-about .media{
  margin:1.8rem 0 0;
  border:1px solid var(--about-rule);
}
.page-about .media img{
  display:block;
  width:100%;
  max-width:100%;
  height:auto;
  object-fit:cover;
}

/* 时间线 */
.page-about .about-timeline{
  list-style:none;
  position:relative;
  margin:2rem 0 0;
  padding:0 0 0 1.6rem;
}
.page-about .about-timeline::before{
  content:"";
  position:absolute;
  left:0;
  top:.5rem;
  bottom:1.4rem;
  width:1px;
  background:linear-gradient(180deg,var(--cyan),rgba(53,224,176,.08));
}
.page-about .about-timeline > li{
  position:relative;
  padding-bottom:1.9rem;
}
.page-about .about-timeline > li:last-child{
  padding-bottom:0;
}
.page-about .about-timeline > li::before{
  content:"";
  position:absolute;
  left:calc(-1.6rem - 4px);
  top:.48rem;
  width:9px;
  height:9px;
  background:var(--night);
  border:1px solid var(--cyan);
}
.page-about .about-timeline__year{
  display:block;
  font-family:var(--font-mono);
  font-size:.86rem;
  letter-spacing:.12em;
  color:var(--amber);
}
.page-about .about-timeline__title{
  margin:.35rem 0 .45rem;
  font-size:1.06rem;
  font-weight:700;
  color:var(--fog);
}
.page-about .about-timeline > li p{
  margin:0;
  max-width:42em;
  font-size:.94rem;
  line-height:1.8;
  color:var(--sage);
}

/* 结尾引导 */
.page-about .about-cta{
  margin-top:clamp(3.2rem,7vw,5.2rem);
  padding:clamp(1.5rem,4vw,2.6rem);
  border:1px solid var(--line-cyan);
  background:
    linear-gradient(135deg,rgba(53,224,176,.1),transparent 58%),
    var(--abyss);
}
.page-about .about-cta__title{
  margin:.7rem 0 0;
  font-family:var(--font-display);
  font-weight:800;
  font-size:clamp(1.28rem,3vw,1.75rem);
  line-height:1.28;
  color:var(--fog);
}
.page-about .about-cta .prose{
  margin-top:1rem;
}
.page-about .about-cta__actions{
  display:flex;
  flex-wrap:wrap;
  gap:.8rem;
  margin-top:1.5rem;
}
<<<END>>>