body {font-family: 'Poppins', sans-serif; margin:0; background:#f9fafb; color:#222; line-height:1.6;}
header {background:#0f172a; color:#fff; text-align:center; padding:30px 20px;}
h1,h2,h3{margin-top:0;}
nav {background:#1e293b; display:flex; justify-content:center; flex-wrap:wrap;}
nav a {color:#fff; padding:12px 18px; text-decoration:none; transition:0.3s;}
nav a:hover {background:#334155;}
main {max-width:900px; margin:30px auto; background:#fff; padding:20px; border-radius:10px; box-shadow:0 3px 10px rgba(0,0,0,0.1);}
ul {padding-left:20px;}
.btn {display:inline-block; background:#2563eb; color:#fff; padding:10px 14px; border-radius:5px; text-decoration:none;}
.btn:hover {background:#1e40af;}
footer {text-align:center; background:#0f172a; color:#fff; padding:15px; font-size:0.9em;}
@media(max-width:600px){main{margin:15px;}}