body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
    background: #f9f9f9;
    color: #333;
}
header, footer {
    background: #2c3e50;
    color: white;
    text-align: center;
    padding: 1em 0;
}
main {
    padding: 20px;
    max-width: 900px;
    margin: auto;
}
a {
    color: #3498db;
    text-decoration: none;
}
button, .buy-btn {
    background: #27ae60;
    color: white;
    padding: 10px 15px;
    border: none;
    border-radius: 4px;
    text-decoration: none;
    display: inline-block;
    margin-top: 10px;
}
.buy-btn:hover, button:hover {
    background: #2ecc71;
}
.nav-links {
    margin: 1em 0;
}
.nav-links a {
    margin: 0 10px;
    color: #ecf0f1;
}