:root{
  --primary:#0064d2;
  --primary-dark:#004da3;
  --accent:#ff7a00;
  --text:#172033;
  --muted:#64748b;
  --line:#e2e8f0;
  --soft:#f8fafc;
  --blue-soft:#eaf4ff;
  --dark:#07111f;
  --radius:20px;
  --container:960px;
  --font:Inter,Arial,sans-serif;
}
*{box-sizing:border-box}
body{
  margin:0;
  font-family:var(--font);
  color:var(--text);
  background:#fff;
  line-height:1.75;
}
a{
  color:var(--primary);
  text-decoration:none;
}
a:hover{text-decoration:underline}
img{
  max-width:100%;
  height:auto;
  display:block;
}
.container{
  width:min(var(--container),calc(100% - 32px));
  margin:auto;
}
.header{
  background:#fff;
  border-bottom:1px solid var(--line);
  position:sticky;
  top:0;
  z-index:99;
}
.nav{
  display:flex;
  justify-content:space-between;
  align-items:center;
  gap:20px;
  padding:15px 0;
}
.brand{
  color:var(--primary);
  font-size:22px;
  font-weight:900;
}
.menu{
  display:flex;
  gap:16px;
  flex-wrap:wrap;
}
.menu a{
  color:#334155;
  font-weight:700;
  font-size:14px;
}
.hero{
  background:linear-gradient(180deg,#eaf4ff 0%,#fff 100%);
  padding:54px 0 32px;
}
.badge{
  display:inline-block;
  background:#fff;
  border:1px solid rgba(0,100,210,.18);
  color:var(--primary);
  padding:7px 12px;
  border-radius:999px;
  font-size:14px;
  font-weight:800;
}
h1{
  font-size:clamp(32px,5vw,52px);
  line-height:1.1;
  letter-spacing:-1px;
  margin:18px 0 14px;
}
h2{
  font-size:30px;
  line-height:1.2;
  margin-top:34px;
}
h3{
  font-size:22px;
  margin-top:26px;
}
p,li{
  color:#475569;
  font-size:17px;
}
.article{
  padding:28px 0 50px;
}
.featured-img{
  margin:24px 0;
  border-radius:24px;
  overflow:hidden;
  background:#f1f5f9;
  border:1px solid var(--line);
}
.box{
  background:var(--soft);
  border:1px solid var(--line);
  border-radius:20px;
  padding:20px;
  margin:24px 0;
}
.toc{
  background:#fff;
  border:1px solid var(--line);
  border-radius:20px;
  padding:20px;
  margin:24px 0;
}
.cta{
  background:linear-gradient(135deg,var(--primary-dark),#0077ff);
  color:#fff;
  border-radius:26px;
  padding:28px;
  margin:36px 0;
}
.cta p{color:rgba(255,255,255,.88)}
.btn{
  display:inline-block;
  background:var(--accent);
  color:#fff;
  padding:12px 18px;
  border-radius:999px;
  font-weight:900;
  margin-top:10px;
}
.related{
  border-top:1px solid var(--line);
  padding-top:24px;
  margin-top:40px;
}
.grid{
  display:grid;
  grid-template-columns:repeat(2,1fr);
  gap:18px;
}
.card{
  background:#fff;
  border:1px solid var(--line);
  border-radius:20px;
  padding:22px;
}
.footer{
  background:var(--dark);
  color:#cbd5e1;
  padding:34px 0;
}
.footer p{color:#cbd5e1}
.footer a{color:#cbd5e1}
.breadcrumb{
  font-size:14px;
  color:var(--muted);
  margin-top:18px;
}
.breadcrumb a{color:var(--muted)}
@media(max-width:720px){
  .nav{display:block}
  .menu{margin-top:10px}
  .grid{grid-template-columns:1fr}
}