*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
:root{
  --sky:#0284c7;
  --sky-dark:#0369a1;
  --sky-deep:#075985;
  --sky-light:#e0f2fe;
  --sky-soft:#bae6fd;
  --sky-pale:#f0f9ff;
  --ink:#0c4a6e;
  --ink-body:#164e63;
  --muted:#64748b;
  --line:#cbd5e1;
  --white:#fff;
  --diag:-5deg;
  --max:1080px;
  --radius:12px;
}
html{scroll-behavior:smooth;scroll-padding-top:72px}
body{font-family:"Noto Sans SC",system-ui,sans-serif;background:var(--sky-pale);color:var(--ink-body);line-height:1.85;font-size:16px;min-height:100vh;overflow-x:hidden}
img{max-width:100%;height:auto;display:block}
a{color:var(--sky-dark);text-decoration:none;font-weight:500}
a:hover{text-decoration:underline;color:var(--sky-deep)}
.container{width:min(100% - 2rem,var(--max));margin-inline:auto}

.site-header{position:sticky;top:0;z-index:200;background:rgba(255,255,255,.94);backdrop-filter:blur(10px);border-bottom:2px solid var(--sky-soft)}
.header-row{display:flex;align-items:center;justify-content:space-between;min-height:64px;gap:1rem}
.brand{display:flex;align-items:center;gap:.6rem;font-weight:700;color:var(--ink);text-decoration:none;font-size:1rem}
.brand:hover{text-decoration:none;color:var(--sky)}
.brand img{border-radius:8px}
.site-nav ul{display:flex;flex-wrap:wrap;gap:.15rem 1.1rem;list-style:none}
.site-nav a{color:var(--muted);font-size:.92rem;text-decoration:none;padding:.25rem 0;border-bottom:2px solid transparent}
.site-nav a.active,.site-nav a:hover{color:var(--sky);border-bottom-color:var(--sky-soft)}
.nav-toggle{display:none;border:1px solid var(--line);width:42px;height:42px;border-radius:8px;cursor:pointer;flex-direction:column;justify-content:center;align-items:center;gap:5px;background:#fff}
.nav-toggle span{width:20px;height:2px;background:var(--ink);display:block;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)}

.ads-top-bar{padding:.5rem 0;background:#fff;border-bottom:1px solid var(--line)}
.applist-title{font-size:.78rem;color:var(--muted);text-align:center;margin-bottom:.4rem}
#ads{display:flex;justify-content:center;flex-wrap:wrap;gap:.4rem}
.ads-item figure{margin:0;text-align:center}
.ads-item img{width:65px;height:65px;border-radius:10px;object-fit:cover;border:1px solid var(--line)}
.ads-item .caption{font-size:11px;color:var(--muted);max-width:76px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}

.hero-diag{position:relative;padding:3rem 0 2.5rem;overflow:hidden}
.hero-diag::before{
  content:"";position:absolute;left:-8%;right:-8%;top:-30%;bottom:-20%;
  background:linear-gradient(120deg,var(--sky) 0%,var(--sky-dark) 55%,#0ea5e9 100%);
  transform:skewY(var(--diag));z-index:0;
}
.hero-inner{position:relative;z-index:1;color:#fff}
.hero-inner h1{font-size:clamp(1.5rem,3.5vw,2.15rem);line-height:1.35;margin-bottom:1rem;font-weight:700}
.hero-inner .lead{font-size:1.05rem;line-height:1.9;color:rgba(255,255,255,.92);text-align:justify;margin-bottom:.75rem}
.hero-inner a{color:var(--sky-soft)}
.hero-grid{display:grid;grid-template-columns:1.15fr 1fr;gap:2rem;align-items:center}
.hero-visual img{border-radius:var(--radius);box-shadow:0 16px 40px rgba(0,0,0,.22);border:3px solid rgba(255,255,255,.25)}

.link-strip{display:flex;flex-wrap:wrap;gap:.65rem;padding:1.5rem 0}
.link-strip a{
  padding:.55rem 1.1rem;border-radius:999px;font-size:.9rem;font-weight:600;
  background:#fff;color:var(--sky);border:2px solid var(--sky-soft);
  box-shadow:0 4px 14px rgba(2,132,199,.12);transition:background .2s,color .2s;
}
.link-strip a:hover{background:var(--sky);color:#fff;text-decoration:none}

.diag-band{position:relative;padding:3.5rem 0;overflow:hidden}
.diag-band::before{
  content:"";position:absolute;left:-6%;right:-6%;top:-1.5rem;bottom:-1.5rem;z-index:0;
  transform:skewY(var(--diag));
}
.diag-band:nth-of-type(odd)::before{background:linear-gradient(135deg,var(--sky-light),#fff)}
.diag-band:nth-of-type(even)::before{background:linear-gradient(135deg,var(--sky),var(--sky-dark))}
.diag-band:nth-of-type(even){color:#fff}
.diag-band:nth-of-type(even) a{color:var(--sky-soft)}
.diag-band:nth-of-type(even) h2{color:#fff}
.diag-band:nth-of-type(even) .callout{background:rgba(255,255,255,.12);border-color:rgba(255,255,255,.35);color:#fff}
.diag-band:nth-of-type(even) .callout strong{color:var(--sky-soft)}

.diag-inner{position:relative;z-index:1}
.diag-inner h2{font-size:1.22rem;color:var(--sky);margin-bottom:1rem;line-height:1.4}
.diag-grid{display:grid;grid-template-columns:1fr 1fr;gap:1.75rem;align-items:start}
.diag-inner p{margin-bottom:.95rem;text-align:justify;font-size:1.01rem}
.diag-inner ul,.diag-inner ol{margin:0 0 1rem 1.2rem}
.diag-inner li{margin-bottom:.4rem}

.callout{
  padding:1rem 1.15rem;border-radius:var(--radius);margin:1rem 0;
  background:rgba(2,132,199,.08);border-left:4px solid var(--sky);
  font-size:.95rem;line-height:1.7;
}
.callout strong{display:block;margin-bottom:.3rem;color:var(--sky-dark);font-size:.82rem;letter-spacing:.04em}

.feature-img{margin:1rem 0}
.feature-img img{border-radius:var(--radius);border:2px solid var(--line);box-shadow:0 8px 24px rgba(2,132,199,.1)}
.feature-img figcaption{font-size:.78rem;color:var(--muted);text-align:center;padding:.45rem 0}

.faq-block{padding:2.5rem 0}
.faq-block h2{font-size:1.15rem;color:var(--sky);margin-bottom:1rem}
.faq-block details{border:1px solid var(--line);border-radius:var(--radius);padding:.9rem 1rem;margin-bottom:.6rem;background:#fff}
.faq-block summary{cursor:pointer;font-weight:600;color:var(--ink)}
.faq-block p{margin-top:.5rem;color:var(--ink-body)}

.related-read{margin:2rem 0 3rem;padding:1.35rem;border-radius:var(--radius);border:1px solid var(--line);background:#fff}
.related-read h2{font-size:1.05rem;color:var(--sky);margin-bottom:.85rem}
.related-grid{display:flex;flex-wrap:wrap;gap:.5rem}
.related-grid a{padding:.4rem .85rem;border:1px solid var(--line);border-radius:8px;font-size:.86rem;color:var(--ink-body);background:var(--sky-pale)}
.related-grid a:hover{border-color:var(--sky);color:var(--sky)}

.page-head{padding:2rem 0 1rem;border-bottom:1px solid var(--line)}
.breadcrumb{font-size:.84rem;color:var(--muted);margin-bottom:.4rem}
.breadcrumb a{color:var(--muted)}
.prose-page{padding:2rem 0 3rem}
.prose-page h2{color:var(--sky);margin:1.3rem 0 .75rem;font-size:1.08rem}
.prose-page p{margin-bottom:.88rem;text-align:justify}

.site-footer{border-top:2px solid var(--sky-soft);padding:1.5rem 0;text-align:center;color:var(--muted);font-size:.86rem;background:#fff}
.footer-links{display:flex;justify-content:center;gap:1rem;margin-bottom:.45rem;flex-wrap:wrap}
.footer-links a{color:var(--muted);text-decoration:none}
.footer-links a:hover{color:var(--sky)}

.error-page{min-height:50vh;display:flex;align-items:center;justify-content:center;text-align:center;padding:2rem}
.error-page h1{font-size:3.2rem;color:var(--sky)}

@media(max-width:768px){
  .hero-grid,.diag-grid{grid-template-columns:1fr}
  .site-nav{position:absolute;top:100%;left:0;right:0;background:#fff;border-bottom:1px solid var(--line);padding:1rem;display:none}
  .site-header{position:relative}
  .site-nav.is-open{display:block}
  .site-nav ul{flex-direction:column}
  .nav-toggle{display:flex}
}