body { font-family: Arial; margin:0; padding:0; }
header { background-color: #004AAD; color: #FFD700; padding: 10px; text-align: center; }
nav a { margin: 0 10px; color: #FFD700; text-decoration: none; }
button { background-color: #004AAD; color: #fff; padding: 10px; border: none; cursor: pointer; }
.whatsapp-float { position: fixed; bottom: 20px; right: 20px; z-index: 100; }
@media (max-width: 768px) {
  nav a { display:block; margin:10px 0; }
  header h1 { font-size: 24px; }
}