/* 1. Element Name Selector */
body {
    font-family: Arial, sans-serif;
    background-color: #f0f4f8;
    padding: 40px;
}

/* 2. ID Selector (matches the h1) */
#page-header {
    color: #2c3e50;
    border-bottom: 2px solid #2c3e50;
}

/* 3. Class Name Selector (matches the section with the content) */
.content-section {
    background-color: white;
    padding: 20px;
    border-radius: 10px;
    box-shadow: 0 4px 8px rgba(0,0,0,0.1);
}