CSS Selectors

HTML

<div id="main">
    <p>Paragraph #1</p>
    <p>Paragraph #2</p>
    <div>
        <p>Child Paragraph</p>
    </div>
    <p>Paragraph #3</p>
    <p>Paragraph #4</p>
    <div>
        <p>Child Paragraph #1</p>
        <p>Child Paragraph #2</p>
    </div>
    <p>Paragraph #5</p>
    <p>Paragraph #6</p>
</div>

CSS

div#main p {
    font-weight: bold;
}
div#main > p {
    border: 1px solid black;
}
div + p {
    text-transform: uppercase;
}
div ~ p {
    background-color: red;
}