body{margin:0;font-family:Arial;}
.hero{
  position:relative;
  height:100vh;
  background:linear-gradient(135deg,#061a33,#0d6efd);
  color:white;
  display:flex;
  align-items:center;
  justify-content:center;
  text-align:center;
  padding:20px;
}
.overlay{position:absolute;inset:0;background:rgba(0,0,0,0.25);}
.content{position:relative;max-width:900px;}
.brand{font-size:22px;letter-spacing:3px;color:#00ff9d;}
.tagline{font-size:14px;margin:10px 0;color:#b7ffdf;}
h1{font-size:42px;margin:20px 0;}
.sub{opacity:0.9}
.cta{margin-top:20px;}
.btn{padding:12px 20px;margin:5px;text-decoration:none;border-radius:6px;display:inline-block}
.primary{background:#00c853;color:white}
.ghost{border:1px solid white;color:white}
.stats{margin-top:30px;display:flex;gap:15px;justify-content:center;flex-wrap:wrap;font-size:13px}
.section{padding:60px 20px;text-align:center}
.dark{background:#0b1f3a;color:white}
.grid{display:flex;gap:20px;justify-content:center;flex-wrap:wrap}
.card{background:white;padding:20px;width:240px;border-radius:10px}
.zalo{
 position:fixed;
 right:20px;
 bottom:20px;
 background:#0068ff;
 color:white;
 padding:14px 18px;
 border-radius:50px;
 text-decoration:none;
}
footer{text-align:center;padding:20px;background:#111;color:white}