.page-about{
  --about-cut:18px;
  --about-gap:clamp(20px,4vw,44px);
  --about-orange-soft:rgba(255,122,41,.14);
  --about-green-soft:rgba(76,224,138,.16);
  --about-panel-hi:#16294F;
  background:var(--c-void);
  color:var(--c-white);
  font-family:var(--font-sans);
  overflow-x:hidden;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero{
  position:relative;
  overflow:hidden;
  padding:calc(var(--header-h) + 28px) 0 clamp(40px,7vw,72px);
}
.page-about .about-hero::before{
  content:"";
  position:absolute;
  inset:0;
  background-image:
    linear-gradient(rgba(34,58,110,.5) 1px,transparent 1px),
    linear-gradient(90deg,rgba(34,58,110,.5) 1px,transparent 1px);
  background-size:76px 76px;
  opacity:.32;
  pointer-events:none;
}
.page-about .about-hero::after{
  content:"";
  position:absolute;
  top:-200px;
  right:-160px;
  width:min(620px,82vw);
  height:min(620px,82vw);
  background:radial-gradient(circle,rgba(255,122,41,.2),transparent 62%);
  pointer-events:none;
}
.page-about .about-hero__inner{position:relative;z-index:1;}
.page-about .about-crumbs{margin:0 0 clamp(20px,4vw,32px);font-size:12px;letter-spacing:.08em;color:var(--c-mute);}
.page-about .about-crumbs a{color:var(--c-mute);text-decoration:none;}
.page-about .about-crumbs a:hover{color:var(--c-orange);}
.page-about .about-hero__title{
  margin:14px 0 0;
  max-width:1080px;
  font-size:clamp(34px,7.4vw,84px);
  line-height:.99;
  letter-spacing:-.03em;
  font-weight:900;
}
.page-about .about-hero__lead{
  margin:clamp(18px,3vw,26px) 0 0;
  max-width:62ch;
  font-size:clamp(15px,1.6vw,17px);
  line-height:1.8;
  color:var(--c-mute);
}
.page-about .about-hero__stats{
  display:grid;
  grid-template-columns:repeat(auto-fit,minmax(140px,1fr));
  gap:1px;
  margin:clamp(28px,5vw,44px) 0 0;
  background:var(--c-line);
  border:1px solid var(--c-line);
}
.page-about .stat{background:var(--c-void);padding:16px 18px;}
.page-about .stat__key{font-size:11px;letter-spacing:.18em;color:var(--c-mute);}
.page-about .stat__val{
  margin:10px 0 0;
  font-family:var(--font-mono);
  font-variant-numeric:tabular-nums;
  font-size:clamp(19px,2.6vw,26px);
  line-height:1.1;
  color:var(--c-white);
}
.page-about .stat--accent .stat__val{color:var(--c-orange);}
.page-about .about-hero__trace{
  display:none;
  position:absolute;
  right:0;
  bottom:clamp(20px,4vw,44px);
  width:min(560px,48%);
  height:auto;
  opacity:.85;
  pointer-events:none;
}

/* ---------- 主体骨架 ---------- */
.page-about .about-body{padding-bottom:clamp(40px,7vw,80px);}
.page-about .about-flow{min-width:0;}

.page-about .about-rail{display:none;}

@media (min-width:1200px){
  .page-about .about-body{
    display:grid;
    grid-template-columns:88px minmax(0,1fr);
    gap:var(--about-gap);
    align-items:start;
  }
  .page-about .about-rail{
    display:block;
    position:sticky;
    top:calc(var(--header-h) + 28px);
  }
  .page-about .about-rail__list{list-style:none;margin:0;padding:0;display:grid;gap:4px;}
  .page-about .about-rail__link{
    display:block;
    padding:8px 0 8px 14px;
    border-left:1px solid var(--c-line);
    font-family:var(--font-mono);
    font-size:12px;
    letter-spacing:.1em;
    color:var(--c-mute);
    text-decoration:none;
    transition:color .18s var(--ease),border-color .18s var(--ease);
  }
  .page-about .about-rail__link:hover,
  .page-about .about-rail__link:focus-visible,
  .page-about .about-rail__link[data-active="true"]{
    color:var(--c-white);
    border-left-color:var(--c-orange);
  }
}

/* ---------- 章节抬头 ---------- */
.page-about .about-sec{
  position:relative;
  padding:clamp(36px,6vw,64px) 0;
  border-top:1px solid var(--c-line);
}
.page-about .about-sec:first-child{border-top:0;}
.page-about .sec-head{margin-bottom:clamp(22px,3.4vw,34px);}
.page-about .sec-head__index{
  margin:0;
  font-family:var(--font-mono);
  font-size:12px;
  letter-spacing:.18em;
  color:var(--c-orange);
}
.page-about .sec-head__title{
  margin:10px 0 0;
  font-size:clamp(23px,3.6vw,34px);
  line-height:1.18;
  letter-spacing:-.02em;
  font-weight:800;
}
.page-about .sec-head__note{margin:10px 0 0;font-size:14px;line-height:1.7;color:var(--c-mute);}

/* ---------- 双栏 ---------- */
.page-about .split{display:grid;gap:var(--about-gap);}
@media (min-width:900px){
  .page-about .split{grid-template-columns:7fr 5fr;align-items:start;}
  .page-about .split--flip{grid-template-columns:5fr 7fr;}
}
.page-about .prose p{margin:0 0 16px;font-size:16px;line-height:1.8;color:var(--c-white);}
.page-about .prose p:last-child{margin-bottom:0;}

.page-about .about-quote{
  margin:0;
  padding:4px 0 4px 18px;
  border-left:3px solid var(--c-orange);
  font-size:15px;
  line-height:1.8;
  color:var(--c-mute);
}
.page-about .about-quote strong{display:block;margin-bottom:8px;font-size:17px;font-weight:800;color:var(--c-white);letter-spacing:-.01em;}
.page-about .about-facts{list-style:none;margin:22px 0 0;padding:0;display:grid;gap:10px;}
.page-about .about-facts li{
  display:flex;
  gap:12px;
  align-items:baseline;
  padding-bottom:10px;
  border-bottom:1px dashed var(--c-line);
  font-size:14px;
  color:var(--c-mute);
}
.page-about .about-facts .mono{
  font-family:var(--font-mono);
  font-variant-numeric:tabular-nums;
  font-size:20px;
  color:var(--c-green);
  min-width:34px;
}

/* ---------- 时间线 ---------- */
.page-about .about-chips{display:flex;flex-wrap:wrap;gap:10px;margin:0 0 clamp(26px,4vw,38px);}
.page-about .about-chip{
  display:inline-flex;
  align-items:center;
  min-height:44px;
  padding:0 16px;
  border:1px solid var(--c-line);
  color:var(--c-mute);
  font-size:13px;
  text-decoration:none;
  transition:color .18s var(--ease),border-color .18s var(--ease),background .18s var(--ease);
}
.page-about .about-chip:hover,
.page-about .about-chip:focus-visible{color:var(--c-white);border-color:var(--c-orange);background:var(--about-orange-soft);}

.page-about .about-line{position:relative;}
.page-about .about-line::before{
  content:"";
  position:absolute;
  left:7px;
  top:6px;
  bottom:6px;
  width:1px;
  background:linear-gradient(180deg,var(--c-orange),var(--c-line) 20%,var(--c-line) 76%,transparent);
}
.page-about .stage{position:relative;padding:0 0 30px 36px;}
.page-about .stage:last-child{padding-bottom:0;}
.page-about .stage__node{
  position:absolute;
  left:0;
  top:6px;
  width:15px;
  height:15px;
  border:1px solid var(--c-line);
  background:var(--c-void);
  transition:background .3s var(--ease),border-color .3s var(--ease),box-shadow .3s var(--ease);
}
.page-about .stage.is-in .stage__node{
  background:var(--c-green);
  border-color:var(--c-green);
  box-shadow:0 0 0 5px var(--about-green-soft);
}
.page-about .stage__index{
  margin:0 0 6px;
  font-family:var(--font-mono);
  font-size:11px;
  letter-spacing:.2em;
  color:var(--c-orange);
}
.page-about .stage__title{margin:0 0 8px;font-size:clamp(19px,2.4vw,24px);font-weight:800;letter-spacing:-.01em;}
.page-about .stage__text{margin:0;max-width:54ch;font-size:15px;line-height:1.78;color:var(--c-mute);}

@media (min-width:900px){
  .page-about .about-line::before{left:50%;}
  .page-about .stage{width:50%;padding:0 52px 46px 0;}
  .page-about .stage:nth-child(even){margin-left:50%;padding:0 0 46px 52px;}
  .page-about .stage__node{left:auto;right:-8px;top:9px;}
  .page-about .stage:nth-child(even) .stage__node{left:-8px;right:auto;}
  .page-about .stage:last-child{padding-bottom:0;}
}

/* ---------- 图片切角 ---------- */
.page-about .about-shot{margin:clamp(28px,5vw,48px) 0 0;}
.page-about .about-shot--lead{margin-top:0;}
.page-about .about-shot__frame{
  position:relative;
  overflow:hidden;
  clip-path:polygon(0 0,calc(100% - var(--about-cut)) 0,100% var(--about-cut),100% 100%,var(--about-cut) 100%,0 calc(100% - var(--about-cut)));
  background:var(--c-panel);
}
.page-about .about-shot__frame .media{aspect-ratio:16/9;margin:0;position:relative;}
.page-about .about-shot--sq .about-shot__frame .media{aspect-ratio:1/1;}
.page-about .about-shot__frame img{display:block;width:100%;height:100%;object-fit:cover;}
.page-about .about-shot figcaption{margin:12px 0 0;font-size:13px;line-height:1.7;color:var(--c-mute);}

/* ---------- 岗位分工 ---------- */
.page-about .about-roles{
  list-style:none;
  margin:clamp(22px,3.4vw,30px) 0 0;
  padding:0;
  display:grid;
  gap:1px;
  background:var(--c-line);
  border:1px solid var(--c-line);
}
.page-about .role{
  display:grid;
  grid-template-columns:auto 1fr;
  gap:4px 16px;
  align-items:baseline;
  padding:16px 18px;
  background:var(--c-panel);
  border-left:2px solid transparent;
  transition:border-color .18s var(--ease),background .18s var(--ease);
}
.page-about .role:hover,
.page-about .role:focus-within{border-left-color:var(--c-orange);background:var(--about-panel-hi);}
.page-about .role__num{
  font-family:var(--font-mono);
  font-variant-numeric:tabular-nums;
  font-size:clamp(22px,2.8vw,28px);
  line-height:1;
  color:var(--c-orange);
}
.page-about .role__name{font-size:16px;font-weight:700;letter-spacing:-.01em;}
.page-about .role__note{grid-column:1/-1;margin:8px 0 0;font-size:14px;line-height:1.72;color:var(--c-mute);}
.page-about .role:hover .role__note{color:var(--c-white);}

/* ---------- 三道环节 ---------- */
.page-about .about-steps{
  list-style:none;
  margin:0;
  padding:0;
  display:grid;
  gap:1px;
  background:var(--c-line);
  border:1px solid var(--c-line);
}
.page-about .step{position:relative;padding:20px 18px 20px 56px;background:var(--c-panel);}
.page-about .step__no{
  position:absolute;
  left:18px;
  top:21px;
  font-family:var(--font-mono);
  font-size:13px;
  letter-spacing:.08em;
  color:var(--c-green);
}
.page-about .step__title{margin:0 0 6px;font-size:16px;font-weight:700;}
.page-about .step__text{margin:0;font-size:14px;line-height:1.75;color:var(--c-mute);}

.page-about .about-kv{list-style:none;margin:clamp(20px,3vw,28px) 0 0;padding:0;display:grid;gap:10px;}
.page-about .about-kv__row{display:grid;gap:4px;padding-bottom:10px;border-bottom:1px dashed var(--c-line);}
.page-about .about-kv__key{font-size:12px;letter-spacing:.1em;color:var(--c-mute);}
.page-about .about-kv__val{
  font-family:var(--font-mono);
  font-variant-numeric:tabular-nums;
  font-size:16px;
  color:var(--c-white);
}
@media (min-width:560px){
  .page-about .about-kv__row{grid-template-columns:190px 1fr;align-items:baseline;gap:16px;}
}

/* ---------- 覆盖与协作 ---------- */
.page-about .about-sec--band{
  background:linear-gradient(180deg,rgba(18,34,74,.9),rgba(10,22,51,.2));
  border-top:1px solid var(--c-line);
  border-bottom:1px solid var(--c-line);
  padding-inline:clamp(14px,2.4vw,24px);
}
.page-about .about-cov{
  display:grid;
  gap:1px;
  background:var(--c-line);
  border:1px solid var(--c-line);
  margin-top:clamp(20px,3vw,28px);
}
.page-about .cov{
  background:var(--c-panel);
  padding:20px 18px 24px;
  clip-path:polygon(0 0,100% 0,100% calc(100% - 14px),calc(100% - 14px) 100%,0 100%);
}
.page-about .cov__num{
  margin:0;
  font-family:var(--font-mono);
  font-variant-numeric:tabular-nums;
  font-size:clamp(26px,3.6vw,34px);
  line-height:1;
  color:var(--c-orange);
}
.page-about .cov__name{margin:12px 0 0;font-size:16px;font-weight:700;}
.page-about .cov__text{margin:8px 0 0;font-size:14px;line-height:1.72;color:var(--c-mute);}
@media (min-width:700px){
  .page-about .about-cov{grid-template-columns:repeat(2,1fr);}
}
@media (min-width:1080px){
  .page-about .about-cov{grid-template-columns:repeat(3,1fr);}
}

/* ---------- 成果 ---------- */
.page-about .about-miles{
  display:grid;
  gap:1px;
  background:var(--c-line);
  border:1px solid var(--c-line);
  margin-top:clamp(20px,3vw,28px);
}
.page-about .mile{background:var(--c-void);padding:22px 18px;}
.page-about .mile__val{
  margin:0;
  font-family:var(--font-mono);
  font-variant-numeric:tabular-nums;
  font-size:clamp(26px,3.6vw,38px);
  line-height:1;
  color:var(--c-orange);
}
.page-about .mile__val span{margin-left:.35em;font-size:.42em;color:var(--c-mute);letter-spacing:.04em;}
.page-about .mile__key{margin:12px 0 0;font-size:13px;line-height:1.7;color:var(--c-mute);}
@media (min-width:640px){
  .page-about .about-miles{grid-template-columns:repeat(2,1fr);}
}
@media (min-width:1000px){
  .page-about .about-miles{grid-template-columns:repeat(3,1fr);}
}

/* ---------- 合作与加入 ---------- */
.page-about .about-partners{display:grid;gap:var(--about-gap);margin-top:clamp(20px,3vw,28px);}
.page-about .partner{
  background:var(--c-panel);
  padding:24px 20px 26px;
  clip-path:polygon(0 0,calc(100% - 20px) 0,100% 20px,100% 100%,0 100%);
  border-left:2px solid var(--c-orange);
}
.page-about .partner__tag{margin:0;font-size:11px;letter-spacing:.18em;color:var(--c-orange);}
.page-about .partner__title{margin:12px 0 0;font-size:18px;font-weight:800;letter-spacing:-.01em;}
.page-about .partner__text{margin:10px 0 0;font-size:14px;line-height:1.78;color:var(--c-mute);}
@media (min-width:800px){
  .page-about .about-partners{grid-template-columns:repeat(3,1fr);}
}

.page-about .about-cta{display:flex;flex-wrap:wrap;gap:12px;margin-top:clamp(24px,4vw,36px);}
.page-about .about-cta__note{
  margin:clamp(18px,3vw,24px) 0 0;
  max-width:64ch;
  font-size:14px;
  line-height:1.8;
  color:var(--c-mute);
  padding-left:16px;
  border-left:2px solid var(--c-line);
}

/* ---------- 窄屏收敛 ---------- */
@media (max-width:479px){
  .page-about{--about-cut:12px;}
  .page-about .about-hero__stats{grid-template-columns:repeat(2,1fr);}
  .page-about .about-chip{font-size:12px;padding:0 12px;}
  .page-about .about-cta .btn{flex:1 1 100%;text-align:center;}
}
@media (min-width:768px){
  .page-about .about-hero{padding-top:calc(var(--header-h) + 56px);}
  .page-about .about-hero__trace{display:block;}
}
@media (prefers-reduced-motion:reduce){
  .page-about .stage__node,
  .page-about .role,
  .page-about .about-chip{transition:none;}
}