*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
:root{
  --ink:#1a1423;--muted:#5c5470;--line:#e8e0f0;
  --plum:#6d28d9;--plum-deep:#5b21b6;--plum-soft:#f5f3ff;
  --rose:#be185d;--rose-soft:#fdf2f8;
  --slate:#334155;--header-h:58px;--content:880px;--spine:56px;
}
html{scroll-behavior:smooth}
body{font-family:"Noto Sans SC",system-ui,sans-serif;color:var(--ink);background:#fff;line-height:1.85;font-size:16px}
img{max-width:100%;height:auto;display:block}
a{color:var(--plum-deep);text-decoration:none}
a:hover{text-decoration:underline}

.site-header{position:sticky;top:0;z-index:400;background:#fff;border-bottom:3px solid var(--plum)}
.header-inner{max-width:1000px;margin:0 auto;padding:0 1rem;display:flex;align-items:center;justify-content:space-between;min-height:var(--header-h)}
.brand{display:flex;align-items:center;gap:.7rem;color:var(--ink);font-size:.9rem;text-decoration:none}
.brand:hover{text-decoration:none}
.brand em{font-style:normal;font-weight:700;color:var(--plum)}
.brand span{line-height:1.35;max-width:360px}

.nav-toggle{display:none;background:none;border:none;cursor:pointer;padding:.5rem;flex-direction:column;gap:5px}
.nav-toggle span{display:block;width:22px;height:2px;background:var(--ink);transition:transform .2s}
.nav-toggle.is-open span:nth-child(1){transform:translateY(7px) rotate(45deg)}
.nav-toggle.is-open span:nth-child(2){opacity:0}
.nav-toggle.is-open span:nth-child(3){transform:translateY(-7px) rotate(-45deg)}

.site-nav ul{display:flex;gap:1rem;list-style:none}
.site-nav a{color:var(--muted);font-size:.88rem;text-decoration:none}
.site-nav a:hover,.site-nav a.active{color:var(--plum);font-weight:600}

.ads-top-bar{background:var(--plum-soft);border-bottom:1px solid var(--line);padding:.55rem 0}
#applist{display:flex;align-items:center;gap:1rem;flex-wrap:wrap}
.applist-title{font-size:.78rem;color:var(--muted);white-space:nowrap}
#ads{display:flex;gap:.75rem;flex-wrap:wrap}
.ads-item figure{margin:0;text-align:center}
.ads-item img{border-radius:10px}
.ads-item .caption{font-size:.68rem;color:var(--muted);margin-top:.2rem;max-width:65px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}

.page-wrap{max-width:var(--content);margin:0 auto;padding:2rem 1.25rem 4.5rem}

.hero-band{
  background:linear-gradient(120deg,var(--plum-soft) 0%,#fff 48%,var(--rose-soft) 100%);
  border:1px solid var(--line);border-right:6px solid var(--plum);
  border-radius:20px 4px 4px 20px;padding:2.1rem 2rem 1.85rem;margin-bottom:2.5rem;
  position:relative;overflow:hidden;
}
.hero-band::after{
  content:"";position:absolute;top:-40px;right:-40px;width:140px;height:140px;
  background:radial-gradient(circle,rgba(109,40,217,.12) 0%,transparent 70%);pointer-events:none;
}
.hero-tag{display:inline-block;font-size:.76rem;font-weight:600;color:var(--plum);background:#fff;border:1px solid var(--plum);padding:.24rem .85rem;border-radius:999px;margin-bottom:.95rem;letter-spacing:.03em}
.hero-band h1{font-size:1.55rem;line-height:1.4;font-weight:700;margin-bottom:.85rem;color:var(--ink);max-width:680px;position:relative;z-index:1}
.hero-lead{font-size:1rem;color:var(--muted);margin-bottom:.65rem;text-align:justify;max-width:720px;position:relative;z-index:1}
.hero-chips{display:flex;flex-wrap:wrap;gap:.5rem;margin-top:1.1rem;position:relative;z-index:1}
.hero-chips span{font-size:.75rem;background:#fff;border:1px solid var(--line);color:var(--slate);padding:.26rem .75rem;border-radius:999px}

.section-jump{display:flex;flex-wrap:wrap;gap:.45rem;margin-bottom:2rem;padding-bottom:1.25rem;border-bottom:2px solid var(--line)}
.section-jump a{font-size:.79rem;color:var(--muted);background:var(--plum-soft);padding:.38rem .75rem;border-radius:999px;border:1px solid transparent}
.section-jump a:hover{color:var(--plum);text-decoration:none;border-color:var(--plum);background:#fff}

.stack-zone{position:relative;padding:1.25rem 0 2rem;perspective:1200px}
.stack-card{
  position:relative;background:#fff;border:1px solid var(--line);
  border-radius:14px;padding:1.55rem 1.7rem 1.5rem calc(var(--spine) + 1.15rem);
  margin-bottom:-1.65rem;
  box-shadow:0 8px 0 rgba(109,40,217,.07),0 2px 8px rgba(26,20,35,.04);
  transform:translateY(calc(var(--depth,0) * 7px)) rotateX(calc(var(--depth,0) * .4deg)) scale(calc(1 - var(--depth,0) * .011));
  opacity:calc(1 - var(--depth,0) * .055);
  transition:transform .34s ease,box-shadow .34s ease,opacity .28s ease,border-color .28s;
  z-index:var(--z,1);cursor:pointer;
}
.stack-card:last-child{margin-bottom:0}
.stack-card.is-front{
  --depth:0;z-index:90!important;opacity:1;
  transform:translateY(-12px) scale(1.015);
  box-shadow:0 18px 48px rgba(109,40,217,.18),0 4px 12px rgba(26,20,35,.06);
  border-color:var(--plum);
}
.stack-card:focus{outline:2px solid var(--plum);outline-offset:4px}
.stack-card:focus:not(:focus-visible){outline:none}

.card-spine{
  position:absolute;left:0;top:0;bottom:0;width:var(--spine);
  background:var(--spine-bg,var(--plum));border-radius:14px 0 0 14px;
  display:flex;flex-direction:column;align-items:center;justify-content:center;gap:.3rem;
  color:#fff;font-size:.7rem;font-weight:600;letter-spacing:.08em;
}
.card-spine .spine-num{font-size:1.08rem;font-weight:700;line-height:1}
.stack-card:nth-child(4n+1){--spine-bg:var(--plum)}
.stack-card:nth-child(4n+2){--spine-bg:#7c3aed}
.stack-card:nth-child(4n+3){--spine-bg:var(--rose)}
.stack-card:nth-child(4n){--spine-bg:#475569}

.card-meta{display:flex;align-items:center;gap:.55rem;margin-bottom:.6rem}
.card-tag{font-size:.71rem;font-weight:600;color:var(--rose);background:var(--rose-soft);padding:.16rem .58rem;border-radius:999px}
.stack-card h2{font-size:1.08rem;color:var(--plum-deep);margin-bottom:.75rem;font-weight:600;line-height:1.42}
.stack-card p{margin-bottom:.88rem;text-align:justify;color:#2d2640}
.stack-card ul{margin:.55rem 0 1rem 1.15rem;color:#2d2640}
.stack-card li{margin-bottom:.36rem}
.stack-card figure{margin:1.05rem 0;border-radius:10px;overflow:hidden;border:1px solid var(--line)}
.stack-card figcaption{font-size:.82rem;color:var(--muted);padding:.55rem .85rem;background:var(--plum-soft);border-top:1px solid var(--line)}

.note-box{
  background:var(--rose-soft);border:1px solid #fbcfe8;border-left:4px solid var(--rose);
  padding:.85rem 1rem;border-radius:0 10px 10px 0;font-size:.92rem;margin:1rem 0;color:#831843;
}
.faq-item{margin-top:1rem;padding-top:.85rem;border-top:1px dashed var(--line)}
.faq-item h3{font-size:.98rem;color:var(--plum-deep);margin-bottom:.45rem;font-weight:600}
.faq-item p{font-size:.94rem;color:var(--muted)}

.bottom-links{display:flex;flex-wrap:wrap;gap:.55rem;margin-top:2.5rem;padding-top:1.45rem;border-top:2px solid var(--line)}
.bottom-links a{font-size:.86rem;color:var(--muted);background:var(--plum-soft);padding:.4rem .95rem;border-radius:999px;border:1px solid var(--line)}
.bottom-links a:hover{color:var(--plum);text-decoration:none;border-color:var(--plum)}

.prose-page{max-width:var(--content);margin:0 auto;padding:2rem 1.25rem 3rem}
.prose-page h1{font-size:1.48rem;margin-bottom:1rem;color:var(--plum)}
.prose-page p{margin-bottom:.95rem}

.error-page{max-width:var(--content);margin:4rem auto;padding:2rem 1.25rem;text-align:center}
.error-page h1{font-size:3rem;color:var(--plum);margin-bottom:.5rem}

.site-footer{background:var(--plum-soft);border-top:3px solid var(--plum);padding:1.5rem 1rem;text-align:center;font-size:.82rem;color:var(--muted)}
.footer-links{display:flex;flex-wrap:wrap;justify-content:center;gap:.5rem 1rem;margin-bottom:.65rem}
.footer-links a{color:var(--muted)}
.footer-sub{font-size:.76rem;margin-top:.35rem;color:#7c7490}

@media(max-width:640px){
  .nav-toggle{display:flex}
  .site-nav{position:absolute;top:100%;left:0;right:0;background:#fff;border-bottom:1px solid var(--line);padding:.75rem 1rem;display:none;box-shadow:0 4px 14px rgba(0,0,0,.06)}
  .site-nav.is-open{display:block}
  .site-nav ul{flex-direction:column;gap:.5rem}
  .stack-card{padding-left:calc(var(--spine) + .85rem);margin-bottom:-1.2rem}
  .hero-band h1{font-size:1.28rem}
  .card-spine{font-size:.62rem}
}