*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
:root{
  --ink:#0f172a;--muted:#475569;--line:#cbd5e1;
  --cobalt:#2563eb;--cobalt-soft:#eff6ff;--coral:#ea580c;--coral-soft:#fff7ed;
  --header-h:58px;--max:1080px;--rail-w:280px;
}
html{scroll-behavior:smooth}
body{font-family:"Noto Sans SC",system-ui,sans-serif;color:var(--ink);background:#fff;line-height:1.78;font-size:16px}
img{max-width:100%;height:auto;display:block}
a{color:var(--cobalt);text-decoration:none}
a:hover{text-decoration:underline}

.site-header{position:sticky;top:0;z-index:400;background:#fff;border-bottom:3px solid var(--cobalt);box-shadow:0 1px 0 var(--line)}
.header-inner{max-width:var(--max);margin:0 auto;padding:0 1.1rem;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:.88rem;text-decoration:none}
.brand:hover{text-decoration:none}
.brand em{font-style:normal;font-weight:700;color:var(--cobalt)}
.brand span{line-height:1.32;max-width:380px}

.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,opacity .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;flex-wrap:wrap}
.site-nav a{color:var(--muted);font-size:.86rem;text-decoration:none;padding:.35rem 0}
.site-nav a:hover,.site-nav a.active{color:var(--cobalt);font-weight:600}

.ads-top-bar{background:var(--cobalt-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:.76rem;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:8px}
.ads-item .caption{font-size:.68rem;color:var(--muted);margin-top:.2rem;max-width:65px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}

.sh-wrap{max-width:var(--max);margin:0 auto;padding:0 1.15rem 3.5rem}
.sh-grid{
  display:grid;grid-template-columns:minmax(0,1fr) var(--rail-w);
  gap:2rem;align-items:start;padding:2.2rem 0 2.5rem;
  border-bottom:2px solid var(--coral);scroll-margin-top:calc(var(--header-h) + 12px);
}
.sh-intro .sh-badge{
  display:inline-flex;align-items:center;gap:.35rem;
  font-size:.74rem;font-weight:600;color:var(--coral);
  background:var(--coral-soft);border:1px solid #fdba74;
  padding:.28rem .85rem;border-radius:999px;margin-bottom:.95rem;
}
.sh-intro h1{font-size:1.68rem;line-height:1.34;font-weight:700;margin-bottom:.9rem;max-width:640px}
.sh-intro .sh-lede{font-size:.98rem;color:var(--muted);text-align:justify;margin-bottom:.7rem;max-width:680px}
.sh-intro .sh-note{font-size:.9rem;color:var(--muted);padding:.85rem 1rem;background:var(--cobalt-soft);border-left:4px solid var(--cobalt);border-radius:0 8px 8px 0;margin-top:1rem}

.sh-rail{
  position:sticky;top:calc(var(--header-h) + 14px);
  background:linear-gradient(165deg,var(--cobalt-soft) 0%,#fff 55%);
  border:1px solid var(--line);border-radius:16px;padding:1.1rem 1rem;
  box-shadow:0 8px 28px rgba(37,99,235,.08);
}
.sh-rail-title{font-size:.72rem;font-weight:700;color:var(--muted);letter-spacing:.06em;margin-bottom:.75rem;text-transform:uppercase}
.sh-rail ol{list-style:none;counter-reset:shstep}
.sh-rail li{counter-increment:shstep;margin-bottom:.45rem}
.sh-rail a{
  display:flex;align-items:center;gap:.55rem;
  font-size:.82rem;color:var(--muted);padding:.48rem .55rem;border-radius:10px;
  border:1px solid transparent;transition:background .15s,border-color .15s,color .15s;
  text-decoration:none;
}
.sh-rail a::before{
  content:counter(shstep);flex-shrink:0;width:1.45rem;height:1.45rem;
  display:flex;align-items:center;justify-content:center;
  font-size:.72rem;font-weight:700;border-radius:50%;
  background:#fff;border:1px solid var(--line);color:var(--muted);
}
.sh-rail a:hover,.sh-rail a.is-active{
  background:#fff;border-color:var(--cobalt);color:var(--cobalt);text-decoration:none;
}
.sh-rail a.is-active::before{background:var(--cobalt);border-color:var(--cobalt);color:#fff}

.sh-body{max-width:780px;padding-top:.5rem}
.sh-section{
  padding:2rem 0 2.1rem;border-bottom:1px dashed var(--line);
  scroll-margin-top:calc(var(--header-h) + 16px);
}
.sh-section:last-child{border-bottom:none}
.sh-section h2{
  font-size:1.18rem;margin-bottom:.85rem;color:var(--ink);
  padding-left:.85rem;border-left:4px solid var(--coral);
}
.sh-section p{margin-bottom:.75rem;text-align:justify;color:#334155;font-size:.97rem}
.sh-section ul,.sh-section ol{margin:.5rem 0 .85rem 1.35rem;color:#334155;font-size:.95rem}
.sh-section li{margin-bottom:.35rem}
.sh-kicker{
  display:inline-block;font-size:.76rem;color:var(--cobalt);
  background:var(--cobalt-soft);padding:.2rem .65rem;border-radius:6px;margin-bottom:.65rem;
}
.sh-fig{margin:1.25rem 0;border-radius:12px;overflow:hidden;border:1px solid var(--line);background:#fff}
.sh-fig figcaption{font-size:.8rem;color:var(--muted);padding:.65rem .9rem;background:var(--cobalt-soft)}
.sh-callout{
  margin:1rem 0;padding:.9rem 1rem;background:var(--coral-soft);
  border:1px solid #fed7aa;border-radius:10px;font-size:.92rem;color:#7c2d12;
}
.sh-faq{margin-top:1.1rem}
.sh-faq dt{font-weight:700;margin-top:.85rem;color:var(--ink);font-size:.95rem}
.sh-faq dd{margin:.35rem 0 .5rem 0;color:#334155;font-size:.94rem;text-align:justify}

.site-footer{background:var(--cobalt-soft);border-top:1px solid var(--line);padding:1.75rem 1.1rem;text-align:center;font-size:.86rem;color:var(--muted)}
.footer-links{display:flex;flex-wrap:wrap;justify-content:center;gap:1rem;margin-bottom:.65rem}
.footer-sub{font-size:.78rem;color:#94a3b8;margin-top:.35rem}

.prose-page{max-width:720px;margin:0 auto;padding:2rem 1.15rem 3rem}
.prose-page h1{font-size:1.42rem;margin-bottom:1rem}
.prose-page p{margin-bottom:.75rem;color:#334155}

@media(max-width:860px){
  .sh-grid{grid-template-columns:1fr;gap:1.25rem;padding:1.5rem 0 1.75rem}
  .sh-rail{position:static}
  .sh-rail ol{display:flex;flex-wrap:wrap;gap:.4rem}
  .sh-rail li{margin:0;flex:1 1 calc(50% - .4rem);min-width:140px}
  .nav-toggle{display:flex}
  .site-nav{
    display:none;position:absolute;top:100%;left:0;right:0;
    background:#fff;border-bottom:1px solid var(--line);padding:.75rem 1.1rem;
    box-shadow:0 6px 18px rgba(15,23,42,.08);
  }
  .site-nav.is-open{display:block}
  .site-nav ul{flex-direction:column;gap:0}
  .header-inner{position:relative}
}