body {
    font-family: Arial, sans-serif;
    margin: 20px;
    background-color: #f9f9f9;
}

nav {
    background-color: #333;
    padding: 10px;
}

nav a {
    color: white;
    margin-right: 15px;
    text-decoration: none;
}

.flash {
    padding: 10px;
    margin: 10px 0;
    border-radius: 5px;
}

.flash.success {
    background-color: #d4edda;
    color: #155724;
}

.flash.warning {
    background-color: #fff3cd;
    color: #856404;
}

.flash.danger {
    background-color: #f8d7da;
    color: #721c24;
}