body{font-family:Arial;margin:0}header,footer{background:#0b3d91;color:#fff;padding:15px}nav a{color:#fff;margin:10px}section{padding:40px}.btn{background:#25D366;color:#fff;padding:10px 15px;text-decoration:none;border-radius:5px}.grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:20px}.card{border:1px solid #ddd;padding:20px}img.logo{height:80px}@media(max-width:600px){nav{display:block}}