*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
:root{
  --ink:#1e1b4b;--muted:#64748b;--line:#e2e8f0;
  --indigo:#4338ca;--indigo-soft:#eef2ff;--amber:#d97706;--amber-soft:#fffbeb;
  --header-h:56px;--content:840px;
}
html{scroll-behavior:smooth}
body{font-family:"Noto Sans SC",system-ui,sans-serif;color:var(--ink);background:#fff;line-height:1.82;font-size:16px}
img{max-width:100%;height:auto;display:block}
a{color:var(--indigo);text-decoration:none}
a:hover{text-decoration:underline}

.site-header{position:sticky;top:0;z-index:300;background:rgba(255,255,255,.97);backdrop-filter:blur(8px);border-bottom:2px solid var(--indigo)}
.header-inner{max-width:1040px;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:.65rem;color:var(--ink);font-size:.86rem;text-decoration:none}
.brand:hover{text-decoration:none}
.brand em{font-style:normal;font-weight:700;color:var(--indigo)}
.brand span{line-height:1.32;max-width:360px}

.nav-toggle{display:none;background:none;border:none;cursor:pointer;padding:.45rem;flex-direction:column;gap:5px}
.nav-toggle span{display:block;width:21px;height:2px;background:var(--ink);transition:transform .22s}
.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:.95rem;list-style:none}
.site-nav a{color:var(--muted);font-size:.84rem;text-decoration:none}
.site-nav a:hover,.site-nav a.active{color:var(--indigo);font-weight:600}

.ads-top-bar{background:var(--indigo-soft);border-bottom:1px solid var(--line);padding:.5rem 0}
#applist{display:flex;align-items:center;gap:1rem;flex-wrap:wrap}
.applist-title{font-size:.74rem;color:var(--muted);white-space:nowrap}
#ads{display:flex;gap:.7rem;flex-wrap:wrap}
.ads-item figure{margin:0;text-align:center}
.ads-item img{border-radius:8px}
.ads-item .caption{font-size:.66rem;color:var(--muted);margin-top:.18rem;max-width:65px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}

.wrap{max-width:var(--content);margin:0 auto;padding:2rem 1.25rem 3.5rem}

.hero-band{
  text-align:center;padding:2.2rem 1.5rem 1.8rem;margin-bottom:2rem;
  background:radial-gradient(ellipse at top,var(--indigo-soft) 0%,#fff 55%,var(--amber-soft) 100%);
  border:1px solid var(--line);border-radius:20px;position:relative;overflow:hidden;
}
.hero-band::after{
  content:"";position:absolute;bottom:0;left:10%;right:10%;height:3px;
  background:linear-gradient(90deg,transparent,var(--indigo),var(--amber),transparent);opacity:.45;
}
.hero-tag{display:inline-block;font-size:.72rem;font-weight:700;color:var(--amber);letter-spacing:.04em;margin-bottom:.75rem;padding:.2rem .65rem;background:#fff;border:1px solid #fde68a;border-radius:20px}
.hero-band h1{font-size:1.62rem;line-height:1.36;font-weight:700;margin-bottom:.9rem;color:#0f172a;max-width:680px;margin-left:auto;margin-right:auto}
.hero-band .lede{font-size:.96rem;color:var(--muted);margin-bottom:.65rem;text-align:justify;max-width:720px;margin-left:auto;margin-right:auto}
.hero-ribbon{
  display:inline-flex;align-items:center;gap:.35rem;margin-top:1rem;
  font-size:.74rem;font-weight:600;color:var(--indigo);background:#fff;border:1px solid var(--indigo);
  padding:.35rem .85rem;border-radius:6px;
}
.hero-ribbon::before{content:"▸";color:var(--amber)}

.chip-row{display:flex;flex-wrap:wrap;justify-content:center;gap:.4rem;margin-top:1.1rem}
.chip-row span{font-size:.72rem;background:#fff;border:1px solid var(--line);color:var(--muted);padding:.2rem .58rem;border-radius:4px}

.section-jump{
  display:flex;flex-wrap:wrap;gap:.45rem;margin-bottom:1.6rem;
  padding:.85rem 0;border-bottom:2px dotted var(--line);
}
.section-jump a{
  font-size:.78rem;color:var(--indigo);background:var(--indigo-soft);
  padding:.32rem .72rem;border-radius:4px;text-decoration:none;border-bottom:2px solid transparent;
  transition:border-color .2s,background .2s;
}
.section-jump a:hover{background:#c7d2fe;border-bottom-color:var(--amber)}

.accord-stack{display:flex;flex-direction:column;gap:.55rem}
.accord-panel{
  border:1px solid var(--line);border-radius:10px;background:#fff;
  border-left:4px solid transparent;overflow:hidden;transition:border-left-color .28s,box-shadow .28s;
}
.accord-panel.is-open{border-left-color:var(--indigo);box-shadow:0 8px 28px rgba(67,56,202,.1)}
.accord-trigger{
  width:100%;display:grid;grid-template-columns:42px 1fr 28px;align-items:center;gap:.75rem;
  padding:1rem 1.15rem;background:linear-gradient(90deg,var(--indigo-soft) 0%,#fff 18%);
  border:none;cursor:pointer;font:inherit;text-align:left;color:var(--ink);
}
.accord-trigger:hover{background:linear-gradient(90deg,#c7d2fe 0%,#fff 22%)}
.accord-num{
  font-size:.82rem;font-weight:800;color:var(--indigo);font-variant-numeric:tabular-nums;
  border-right:2px solid var(--line);padding-right:.6rem;text-align:center;
}
.accord-panel.is-open .accord-num{color:var(--amber)}
.accord-label{font-weight:600;font-size:.94rem;line-height:1.4}
.accord-chevron{
  width:10px;height:10px;border-right:2px solid var(--indigo);border-bottom:2px solid var(--indigo);
  transform:rotate(45deg);transition:transform .32s;margin:auto;
}
.accord-panel.is-open .accord-chevron{transform:rotate(-135deg)}
.accord-content{max-height:0;overflow:hidden;transition:max-height .4s ease}
.accord-panel.is-open .accord-content{max-height:4800px}
.accord-inner{padding:1rem 1.25rem 1.35rem 1.5rem;border-top:1px dashed var(--line)}
.accord-inner p{margin-bottom:.92rem;text-align:justify;color:#334155;font-size:.95rem}
.accord-inner h2{font-size:1.04rem;color:var(--indigo);margin-bottom:.72rem;font-weight:700;padding-left:.65rem;border-left:3px solid var(--amber)}
.accord-inner figure{margin:1.15rem 0;border-radius:8px;overflow:hidden;border:1px solid var(--line);box-shadow:0 2px 12px rgba(0,0,0,.04)}
.accord-inner figcaption{font-size:.79rem;color:var(--muted);padding:.48rem .7rem;background:var(--amber-soft);text-align:center}
.accord-inner ul,.accord-inner ol{margin:.65rem 0 1rem 1.15rem;color:#334155;font-size:.93rem}
.accord-inner li{margin-bottom:.38rem}
.tip-strip{background:var(--amber-soft);border:1px solid #fde68a;padding:.75rem 1rem;border-radius:6px;font-size:.88rem;margin:1rem 0;color:#92400e}

.faq-block{margin-top:2.2rem;padding:1.45rem 1.35rem;background:var(--indigo-soft);border-radius:14px;border:1px solid #c7d2fe}
.faq-block h2{font-size:1.1rem;color:var(--indigo);margin-bottom:1rem}
.faq-item{margin-bottom:1rem;padding-bottom:.95rem;border-bottom:1px dashed #a5b4fc}
.faq-item:last-child{margin-bottom:0;padding-bottom:0;border-bottom:none}
.faq-item h3{font-size:.93rem;color:var(--ink);margin-bottom:.38rem;font-weight:600}
.faq-item p{font-size:.89rem;color:var(--muted);text-align:justify}

.closing-block{margin-top:2rem;padding:1.35rem;background:#fafafa;border-radius:10px;border:1px solid var(--line)}
.closing-block h2{font-size:1.06rem;color:var(--amber);margin-bottom:.7rem}
.closing-block p{font-size:.92rem;color:var(--muted);text-align:justify;margin-bottom:.75rem}

.foot-links{display:flex;flex-wrap:wrap;gap:.55rem;margin-top:1.6rem}
.foot-links a{font-size:.83rem;color:var(--muted);background:var(--indigo-soft);padding:.28rem .75rem;border-radius:4px;text-decoration:none}
.foot-links a:hover{color:var(--indigo)}

.prose-page{max-width:var(--content);margin:0 auto;padding:2rem 1.2rem 3rem}
.prose-page h1{font-size:1.44rem;margin-bottom:1rem;color:var(--indigo)}
.prose-page p{margin-bottom:.9rem}

.error-page{max-width:var(--content);margin:4rem auto;padding:2rem 1.2rem;text-align:center}
.error-page h1{font-size:3rem;color:var(--indigo);margin-bottom:.45rem}

.site-footer{background:var(--indigo-soft);border-top:2px solid var(--indigo);padding:1.5rem 1rem;text-align:center;font-size:.8rem;color:var(--muted)}
.footer-links{display:flex;flex-wrap:wrap;justify-content:center;gap:.45rem 1rem;margin-bottom:.55rem}
.footer-links a{color:var(--muted)}
.footer-sub{font-size:.74rem;margin-top:.3rem;color:#94a3b8}

@media(max-width:768px){
  .nav-toggle{display:flex}
  .site-nav{position:absolute;top:var(--header-h);left:0;right:0;background:#fff;border-bottom:1px solid var(--line);padding:1rem;display:none;box-shadow:0 8px 24px rgba(0,0,0,.06)}
  .site-nav.is-open{display:block}
  .site-nav ul{flex-direction:column;gap:.75rem}
  .site-header{position:relative}
  .hero-band h1{font-size:1.32rem}
  .accord-inner{padding-left:1rem;padding-right:1rem}
  .accord-trigger{grid-template-columns:36px 1fr 24px;padding:.9rem}
}