.page-about{
  --about-cut:18px;
  --about-card-shadow:0 18px 40px -30px rgba(18,18,18,.7);
  --about-line-warm:rgba(18,18,18,.12);
}

/* ============ 首屏 ============ */
.page-about .about-hero{
  position:relative;
  overflow:hidden;
  padding:20px 0 clamp(38px,5vw,70px);
  background:
    radial-gradient(115% 85% at 8% -10%, rgba(139,26,26,.62), transparent 60%),
    radial-gradient(80% 60% at 100% 0%, rgba(30,111,217,.18), transparent 58%),
    linear-gradient(158deg,#121212 0%,#1b1b1b 46%,#2d0f0f 100%);
}
.page-about .about-hero::after{
  content:"";
  position:absolute; left:0; right:0; bottom:0; height:1px;
  background:linear-gradient(90deg,transparent,var(--gold-light),transparent);
  opacity:.55;
}
.page-about .about-crumbs{
  display:flex; flex-wrap:wrap; align-items:center; gap:8px;
  font-size:13px; color:rgba(245,241,232,.62);
}
.page-about .about-crumbs a{
  color:rgba(245,241,232,.82); text-decoration:none;
  border-bottom:1px solid rgba(201,162,39,.45);
  transition:color .2s ease,border-color .2s ease;
}
.page-about .about-crumbs a:hover{ color:var(--gold-light); border-color:var(--gold-light); }

.page-about .hero-frame{
  position:relative;
  margin-top:16px;
  padding:clamp(18px,3.4vw,42px);
  border:1px solid rgba(201,162,39,.34);
  background:
    repeating-linear-gradient(90deg, rgba(201,162,39,.07) 0 1px, transparent 1px 58px),
    linear-gradient(180deg, rgba(255,255,255,.03), rgba(255,255,255,0));
}
.page-about .hero-frame::before,
.page-about .hero-frame::after{
  content:""; position:absolute; width:26px; height:26px; border:2px solid var(--cyan);
}
.page-about .hero-frame::before{ top:-1px; left:-1px; border-right:0; border-bottom:0; }
.page-about .hero-frame::after{ bottom:-1px; right:-1px; border-left:0; border-top:0; }

.page-about .hero-grid{ display:grid; gap:clamp(22px,3vw,38px); }
.page-about .about-hero h1{
  margin:.5rem 0 0;
  font-size:clamp(30px,5.4vw,58px);
  line-height:1.08;
  letter-spacing:-.02em;
  color:var(--warm);
}
.page-about .about-hero .sec-kicker{ color:var(--gold-light); }
.page-about .hero-lede{
  margin:16px 0 0;
  max-width:60ch;
  font-size:clamp(15px,1.15vw,17.5px);
  line-height:1.8;
  color:rgba(245,241,232,.8);
}
.page-about .hero-tags{
  list-style:none; margin:20px 0 0; padding:0;
  display:flex; flex-wrap:wrap; gap:8px;
}
.page-about .hero-actions{
  margin-top:24px;
  display:flex; flex-wrap:wrap; gap:12px;
}

.page-about .hero-figure{
  position:relative; margin:0; overflow:hidden;
  background:#0d0d0d;
  clip-path:polygon(0 0, calc(100% - 22px) 0, 100% 22px, 100% 100%, 22px 100%, 0 calc(100% - 22px));
  border:1px solid rgba(0,229,204,.28);
}
.page-about .hero-figure img{
  display:block; width:100%; height:auto;
  aspect-ratio:16 / 10;
  object-fit:cover;
}
.page-about .hero-figure figcaption{
  position:absolute; left:0; right:0; bottom:0;
  padding:12px 16px;
  font-size:12.5px; letter-spacing:.02em;
  color:rgba(245,241,232,.86);
  background:linear-gradient(180deg, rgba(18,18,18,0), rgba(18,18,18,.88));
}

.page-about .hero-readout{
  list-style:none; margin:clamp(24px,3vw,38px) 0 0; padding:1px;
  display:grid; grid-template-columns:repeat(2, minmax(0,1fr));
  gap:1px;
  background:rgba(201,162,39,.26);
  border:1px solid rgba(201,162,39,.26);
}
.page-about .readout-item{
  background:#151515;
  padding:14px 16px 16px;
  display:flex; flex-direction:column; gap:4px;
}
.page-about .readout-num{
  font-family:var(--font-mono);
  font-size:clamp(21px,2.6vw,30px);
  line-height:1.1;
  color:var(--cyan);
  letter-spacing:-.01em;
}
.page-about .readout-cap{
  font-size:12.5px; color:rgba(245,241,232,.6);
}

/* ============ 时间轴 ============ */
.page-about .about-timeline{
  padding:clamp(46px,7vw,88px) 0;
  background:linear-gradient(180deg,var(--warm) 0%, #EFE9DC 100%);
}
.page-about .about-sec-head{ max-width:760px; }
.page-about .about-timeline .sec-title,
.page-about .about-system .sec-title,
.page-about .about-center .sec-title,
.page-about .about-eco .sec-title{ color:var(--ink); }
.page-about .about-timeline .sec-lede,
.page-about .about-system .sec-lede,
.page-about .about-center .center-copy > p,
.page-about .about-eco .sec-lede{ color:var(--gray); }
.page-about .about-timeline .sec-kicker,
.page-about .about-system .sec-kicker,
.page-about .about-center .sec-kicker,
.page-about .about-eco .sec-kicker{ color:var(--red); }

.page-about .timeline{
  list-style:none; position:relative;
  margin:clamp(30px,4vw,52px) 0 0; padding:0;
}
.page-about .timeline::before{
  content:""; position:absolute; left:19px; top:8px; bottom:8px; width:2px;
  background:linear-gradient(180deg,var(--red) 0%, var(--gold) 52%, var(--cyan) 100%);
  opacity:.55;
}
.page-about .timeline__item{
  position:relative;
  padding-left:56px;
  padding-bottom:clamp(22px,3vw,38px);
}
.page-about .timeline__item:last-child{ padding-bottom:0; }
.page-about .timeline__node{
  position:absolute; left:0; top:0;
  width:40px; height:40px;
  display:grid; place-items:center;
  font-family:var(--font-mono); font-size:13.5px; font-weight:700;
  color:var(--gold-light);
  background:#121212;
  border:1px solid rgba(201,162,39,.7);
  clip-path:polygon(0 0, 100% 0, 100% 68%, 68% 100%, 0 100%);
}
.page-about .timeline__card{
  position:relative;
  padding:clamp(16px,2.2vw,26px);
  background:#fff;
  border:1px solid var(--about-line-warm);
  border-left:4px solid var(--red);
  box-shadow:var(--about-card-shadow);
  transition:transform .25s ease, box-shadow .25s ease, border-color .25s ease;
}
.page-about .timeline__card::before{
  content:""; position:absolute; left:-14px; top:22px; width:14px; height:2px;
  background:var(--gold);
}
.page-about .timeline__item:hover .timeline__card,
.page-about .timeline__item:focus-within .timeline__card{
  transform:translateY(-4px);
  border-left-color:var(--cyan);
  box-shadow:0 22px 44px -30px rgba(18,18,18,.85);
}
.page-about .tl-stage{
  margin:0;
  font-size:12.5px; letter-spacing:.14em;
  color:var(--red); font-weight:700;
}
.page-about .timeline__card h3{
  margin:8px 0 0;
  font-size:clamp(19px,2.1vw,24px);
  color:var(--ink);
  transform:skewX(-4deg);
  transform-origin:left center;
}
.page-about .timeline__card p{
  margin:12px 0 0;
  font-size:15.5px; line-height:1.85; color:#3a3a3a;
}
.page-about .tl-tags{
  list-style:none; margin:16px 0 0; padding:0;
  display:flex; flex-wrap:wrap; gap:8px;
}
.page-about .tl-tag{
  font-family:var(--font-mono);
  font-size:12.5px;
  padding:5px 10px;
  color:var(--gray);
  background:#faf8f3;
  border:1px solid rgba(18,18,18,.16);
  transition:color .2s ease, border-color .2s ease, background .2s ease;
}
.page-about .timeline__item:hover .tl-tag,
.page-about .timeline__item:focus-within .tl-tag{
  color:#0a6f63;
  border-color:rgba(0,229,204,.55);
  background:rgba(0,229,204,.10);
}

/* ============ 服务体系 ============ */
.page-about .about-system{
  padding:clamp(44px,6.5vw,84px) 0;
  background:linear-gradient(180deg,#EBE4D4 0%, #F5F1E8 100%);
}
.page-about .system-grid{ display:grid; gap:clamp(24px,3.4vw,44px); }
.page-about .system-media{
  margin:0; position:relative;
  border:1px solid rgba(18,18,18,.14);
  background:#fff;
  clip-path:polygon(0 0, 100% 0, 100% calc(100% - 20px), calc(100% - 20px) 100%, 0 100%);
  overflow:hidden;
}
.page-about .system-media img{
  display:block; width:100%; height:auto;
  aspect-ratio:10 / 7; object-fit:cover;
}
.page-about .layer-list{
  list-style:none; margin:24px 0 0; padding:0;
  display:grid; gap:12px;
}
.page-about .layer-item{
  display:grid; grid-template-columns:auto 1fr; gap:14px;
  padding:16px 18px;
  background:#fff;
  border:1px solid var(--about-line-warm);
  clip-path:polygon(0 0, calc(100% - 12px) 0, 100% 12px, 100% 100%, 0 100%);
  transition:border-color .2s ease, transform .2s ease;
}
.page-about .layer-item:hover{
  border-color:rgba(201,162,39,.6);
  transform:translateX(4px);
}
.page-about .layer-item__no{
  font-family:var(--font-mono);
  font-size:14px; font-weight:700; color:var(--red);
  line-height:1.6;
}
.page-about .layer-item h3{
  margin:0; font-size:17px; color:var(--ink);
}
.page-about .layer-item p{
  margin:8px 0 0; font-size:14.5px; line-height:1.8; color:#3a3a3a;
}
.page-about .system-link{
  margin:22px 0 0;
  font-size:14.5px; color:var(--gray);
}
.page-about .system-link a,
.page-about .center-link a,
.page-about .eco-note a{
  color:var(--red);
  text-decoration:none;
  border-bottom:1px solid rgba(139,26,26,.4);
  transition:color .2s ease, border-color .2s ease;
}
.page-about .system-link a:hover,
.page-about .center-link a:hover,
.page-about .eco-note a:hover{ color:var(--blue); border-color:var(--blue); }

/* ============ 版本里程碑 ============ */
.page-about .about-version{
  padding:clamp(46px,7vw,88px) 0;
  color:var(--warm);
  background:
    radial-gradient(90% 70% at 88% 8%, rgba(201,162,39,.3), transparent 60%),
    linear-gradient(140deg,#3D0B0B 0%, #8B1A1A 50%, #4A0D0D 100%);
}
.page-about .version-head{ max-width:780px; }
.page-about .version-head .sec-kicker{ color:var(--gold-light); }
.page-about .version-head .sec-title{ color:var(--warm); }
.page-about .version-head .sec-lede{ color:rgba(245,241,232,.76); }

.page-about .version-grid{ display:grid; gap:clamp(22px,3vw,38px); margin-top:clamp(28px,3.6vw,44px); }
.page-about .version-badge{
  position:relative;
  display:flex; flex-direction:column; gap:10px;
  padding:clamp(22px,3vw,34px);
  background:rgba(18,18,18,.42);
  border:1px solid rgba(242,217,132,.4);
  clip-path:polygon(0 0, calc(100% - 24px) 0, 100% 24px, 100% 100%, 0 100%);
}
.page-about .version-badge__label{
  font-size:12.5px; letter-spacing:.18em; color:var(--gold-light);
}
.page-about .version-badge__code{
  font-family:var(--font-mono);
  font-size:clamp(28px,4.4vw,44px);
  line-height:1.1;
  letter-spacing:-.02em;
  color:var(--cyan);
}
.page-about .version-badge__note{
  font-size:13px; color:rgba(245,241,232,.66);
}
.page-about .version-points{
  list-style:none; margin:0; padding:0;
  display:grid; gap:14px;
}
.page-about .version-points li{
  padding:16px 18px;
  background:rgba(255,255,255,.06);
  border-left:3px solid rgba(242,217,132,.6);
  transition:background .2s ease, border-color .2s ease;
}
.page-about .version-points li:hover{
  background:rgba(255,255,255,.12);
  border-left-color:var(--cyan);
}
.page-about .vp-no{
  font-family:var(--font-mono);
  font-size:12.5px; color:var(--gold-light);
}
.page-about .version-points h3{
  margin:6px 0 0; font-size:17px; color:var(--warm);
}
.page-about .version-points p{
  margin:8px 0 0; font-size:14.5px; line-height:1.75; color:rgba(245,241,232,.76);
}

.page-about .version-compare{
  margin-top:clamp(24px,3vw,38px);
  border:1px solid rgba(242,217,132,.38);
  background:rgba(18,18,18,.4);
}
.page-about .version-compare summary{
  list-style:none;
  cursor:pointer;
  display:flex; align-items:center; justify-content:space-between; gap:12px;
  padding:15px 20px;
  font-weight:700; font-size:15.5px;
  color:var(--gold-light);
}
.page-about .version-compare summary::-webkit-details-marker{ display:none; }
.page-about .version-compare summary::after{
  content:"+"; font-family:var(--font-mono); font-size:18px; line-height:1;
}
.page-about .version-compare[open] summary::after{ content:"–"; }
.page-about .compare-grid{
  display:grid; gap:1px;
  padding:0 1px 1px;
  background:rgba(242,217,132,.24);
}
.page-about .compare-col{
  background:rgba(18,18,18,.72);
  padding:18px 20px 22px;
}
.page-about .compare-col h3{
  margin:0; font-size:15px; color:var(--warm);
  letter-spacing:.06em;
}
.page-about .compare-col ul{
  margin:12px 0 0; padding-left:18px;
  display:grid; gap:9px;
}
.page-about .compare-col li{
  font-size:14.5px; line-height:1.7; color:rgba(245,241,232,.78);
}

/* ============ 江苏数字中心 ============ */
.page-about .about-center{
  padding:clamp(44px,6.5vw,84px) 0;
  background:var(--warm);
}
.page-about .center-grid{ display:grid; gap:clamp(24px,3.4vw,44px); }
.page-about .center-copy > p{
  margin:16px 0 0;
  font-size:15.5px; line-height:1.85;
}
.page-about .center-facts{
  list-style:none; margin:24px 0 0; padding:0;
  display:grid; gap:1px;
  background:var(--about-line-warm);
  border:1px solid var(--about-line-warm);
}
.page-about .center-facts li{
  display:grid; grid-template-columns:auto 1fr; gap:14px; align-items:baseline;
  padding:14px 16px;
  background:#fff;
  font-size:14.5px; line-height:1.7; color:#3a3a3a;
}
.page-about .center-facts .mono{
  font-family:var(--font-mono);
  font-size:15px; color:var(--red); font-weight:700;
  white-space:nowrap;
}
.page-about .center-link{
  margin:20px 0 0; font-size:14.5px; color:var(--gray);
}
.page-about .center-media{
  position:relative; margin:0; overflow:hidden;
  border:1px solid var(--about-line-warm);
  clip-path:polygon(20px 0, 100% 0, 100% 100%, 0 100%, 0 20px);
}
.page-about .center-media img{
  display:block; width:100%; height:auto;
  aspect-ratio:3 / 2; object-fit:cover;
}
.page-about .center-media figcaption{
  padding:12px 16px;
  font-size:12.5px; color:var(--gray);
  background:#fff;
  border-top:1px solid var(--about-line-warm);
}

/* ============ 合作与更新 ============ */
.page-about .about-eco{
  padding:clamp(44px,6.5vw,84px) 0;
  background:linear-gradient(180deg,#EFE9DC 0%, #F5F1E8 100%);
}
.page-about .about-eco .sec-head{ max-width:780px; }
.page-about .cadence-grid{
  margin-top:clamp(28px,3.4vw,44px);
  display:grid; gap:14px;
}
.page-about .cadence-card{
  position:relative;
  padding:20px 20px 24px;
  background:#fff;
  border:1px solid var(--about-line-warm);
  border-top:3px solid var(--gold);
  clip-path:polygon(0 0, calc(100% - 14px) 0, 100% 14px, 100% 100%, 0 100%);
  transition:transform .22s ease, box-shadow .22s ease, border-top-color .22s ease;
}
.page-about .cadence-card:hover{
  transform:translateY(-4px);
  border-top-color:var(--cyan);
  box-shadow:0 20px 40px -32px rgba(18,18,18,.85);
}
.page-about .cadence-card h3{
  margin:14px 0 0; font-size:17px; color:var(--ink);
}
.page-about .cadence-card p{
  margin:10px 0 0; font-size:14.5px; line-height:1.8; color:#3a3a3a;
}
.page-about .eco-note{
  margin:26px 0 0;
  font-size:14.5px; color:var(--gray);
}

/* ============ 结尾行动区 ============ */
.page-about .about-cta{
  padding:clamp(34px,5vw,60px) 0;
  background:
    linear-gradient(120deg, rgba(139,26,26,.92), rgba(90,14,14,.96)),
    #121212;
  color:var(--warm);
}
.page-about .about-cta__inner{
  display:grid; gap:20px;
}
.page-about .about-cta h2{
  margin:0;
  font-size:clamp(22px,3vw,32px);
  color:var(--warm);
  transform:skewX(-4deg);
  transform-origin:left center;
}
.page-about .about-cta p{
  margin:12px 0 0;
  max-width:62ch;
  font-size:15px; line-height:1.8;
  color:rgba(245,241,232,.8);
}
.page-about .about-cta__actions{
  display:flex; flex-wrap:wrap; gap:12px;
}

/* ============ 响应式 ============ */
@media (min-width:600px){
  .page-about .cadence-grid{ grid-template-columns:repeat(2, minmax(0,1fr)); }
  .page-about .version-points{ grid-template-columns:repeat(2, minmax(0,1fr)); }
  .page-about .compare-grid{ grid-template-columns:repeat(2, minmax(0,1fr)); }
}
@media (min-width:760px){
  .page-about .hero-readout{ grid-template-columns:repeat(4, minmax(0,1fr)); }
  .page-about .hero-figure img{ aspect-ratio:12 / 5; }
}
@media (min-width:900px){
  .page-about .hero-grid{ grid-template-columns:1.05fr .95fr; align-items:center; }
  .page-about .system-grid{ grid-template-columns:5fr 7fr; align-items:center; }
  .page-about .center-grid{ grid-template-columns:6fr 6fr; align-items:start; }
  .page-about .version-grid{ grid-template-columns:5fr 7fr; align-items:start; }
  .page-about .about-cta__inner{
    grid-template-columns:1.5fr auto;
    align-items:center;
    gap:32px;
  }
  .page-about .about-cta__actions{ justify-content:flex-end; }
}
@media (min-width:1024px){
  .page-about .timeline__card{
    display:grid;
    grid-template-columns:1.45fr .95fr;
    gap:24px;
    align-items:start;
  }
  .page-about .timeline__card > .tl-stage,
  .page-about .timeline__card > h3,
  .page-about .timeline__card > p{ grid-column:1; }
  .page-about .timeline__card > .tl-tags{
    grid-column:2;
    grid-row:1 / span 4;
    margin-top:2px;
    align-content:start;
  }
}
@media (max-width:479px){
  .page-about .hero-frame{ padding:16px; }
  .page-about .hero-frame::before,
  .page-about .hero-frame::after{ width:18px; height:18px; }
  .page-about .timeline__item{ padding-left:48px; }
  .page-about .timeline__node{ width:34px; height:34px; font-size:12px; }
  .page-about .timeline::before{ left:16px; }
  .page-about .timeline__card::before{ left:-12px; width:12px; }
}
@media (prefers-reduced-motion: reduce){
  .page-about .timeline__card,
  .page-about .layer-item,
  .page-about .cadence-card{ transition:none; }
  .page-about .timeline__item:hover .timeline__card,
  .page-about .layer-item:hover,
  .page-about .cadence-card:hover{ transform:none; }
}