To make a `div` expand on hover using CSS, you can use the `:hover` pseudo-class and the `transition` property. The `transition` property allows you to specify the duration, delay, and easing function for the expansion effect.
Here is an example of how you can use CSS to make a `div` expand on hover:
“`css
div {
width: 100px;
height: 100px;
transition: width 1s, height 1s;
}
div:hover {
width: 200px;
height: 200px;
}
“`
In the above code, the `transition` property is applied to the `div`, specifying that the `width` and `height` should be animated over a duration of 1 second. When the `div` is hovered over, the `width` and `height` are set to `200px`, which causes the `div` to expand.
Note that you can also use the `transition` property to specify a delay before the expansion effect is applied, as well as an easing function to control the rate of expansion. For more information about the `transition` property and its available options, you can consult the CSS transitions documentation.