How do you manipulate CSS styles using JavaScript?

You can manipulate CSS styles using JavaScript by accessing the style property of an HTML element. For example, to change the background color of a div element with the id myDiv, you can use:

document.getElementById("myDiv").style.backgroundColor = "blue";

You can also add, remove, or toggle CSS classes using the classList property:

document.getElementById("myDiv").classList.add("newClass");
document.getElementById("myDiv").classList.remove("oldClass");
document.getElementById("myDiv").classList.toggle("toggleClass");