body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
}
nav ul {
    list-style: none;
    display: flex;
    background-color: #333;
    margin: 0;
    padding: 0;
}
nav ul li {
    margin: 0;
}
nav ul li a {
    display: block;
    padding: 1em;
    color: white;
    text-decoration: none;
}
nav ul li a:hover {
    background-color: #555;
}
main {
    padding: 1em;
}
form label {
    display: block;
    margin-bottom: 0.5em;
}
input, select {
    width: 100%;
    max-width: 400px;
    padding: 0.5em;
    margin-bottom: 1em;
}
.success {
    color: green;
}
table {
    width: 100%;
    border-collapse: collapse;
}
th, td {
    padding: 0.5em;
    border: 1px solid #ccc;
}
@media (max-width: 600px) {
    nav ul {
        flex-direction: column;
    }
}
input[readonly], select:disabled {
    background-color: #f9f9f9;
    color: #333;
    border: 1px solid #ccc;
}