body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
}

header {
    background-color: #4CAF50;
    color: white;
    text-align: center;
    padding: 1em;
}

main {
    padding: 1em;
}

.test-container {
    display: flex;
}

.left-column, .right-column {
    flex: 1;
    padding: 1em;
    border: 1px solid #ccc;
}

.left-column {
    background-color: #f9f9f9;
}

.right-column {
    background-color: #fff;
}

table {
    width: 100%;
    border-collapse: collapse;
}

th, td {
    border: 1px solid #ddd;
    padding: 8px;
}

th {
    background-color: #f2f2f2;
}