<html><head><style>div { border: 1px solid black; margin-bottom: 10px;}</style></head><body><div> <h3>H3 element</h3> <p>I am a p element, my parent is a div element.</p></div><div> <h3>H3 element</h3> <p>I am a p element, my parent is also a div element.</p></div><p>Click the button to change the background color of the first p element in the document where the parent is a div element.</p><button onclick="myFunction()">Try it</button><script>function myFunction() { var x = document.querySelector("div > p"); x.style.backgroundColor = "red";}</script></body></html>