body {
    font-family: 'Times New Roman', Times, serif;
    background-color: #f9f9f9;
    margin: 0;
    padding: 20px;
    line-height: 1.6;
    color: #333;
}

h2 {
    color: #2c3e50;
    text-align: center;
    font-size: 24px;
    margin-bottom: 20px;
}

pre {
    background-color: #f4f4f4;
    padding: 15px;
    border: 1px solid #ddd;
    border-radius: 5px;
    font-size: 16px;
    overflow-x: auto;
}
pre > b {
    color: #2c3e50;
}

pre > ul, pre > ol {
    margin: 0;
    padding-left: 20px;
}

pre > ul > li, pre > ol > li {
    margin: 5px 0;
}

pre b:contains('Examples of Valid Identifiers') {
    color: #27ae60;
}

pre b:contains('Examples of Invalid Identifiers') {
    color: #e74c3c;
}