body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
}
header {
    background-color: #333;
    color: white;
    padding: 10px;
    text-align: center;
}
nav a {
    color: white;
    margin: 0 10px;
    text-decoration: none;
}
table {
    width: 100%;
    border-collapse: collapse;
}
table, th, td {
    border: 1px solid black;
}
th, td {
    padding: 10px;
    text-align: left;
}
input, select, button {
    padding: 5px;
    margin: 5px;
}