--- id: 587d78a7367417b2b2512ae0 title: Use CSS Animation to Change the Hover State of a Button challengeType: 0 videoUrl: 'https://scrimba.com/c/cg4vZAa' --- ## Description
You can use CSS @keyframes to change the color of a button in its hover state. Here's an example of changing the width of an image on hover:
<style>
  img:hover {
    animation-name: width;
    animation-duration: 500ms;
  }

  @keyframes width {
    100% {
      width: 40px;
    }
  }
</style>

<img src="https://bit.ly/smallgooglelogo" alt="Google's Logo" />
## Instructions
Note that ms stands for milliseconds, where 1000ms is equal to 1s. Use CSS @keyframes to change the background-color of the button element so it becomes #4791d0 when a user hovers over it. The @keyframes rule should only have an entry for 100%.
## Tests
```yml tests: - text: The @keyframes rule should use the animation-name background-color. testString: assert(code.match(/@keyframes\s+?background-color\s*?{/g), 'The @keyframes rule should use the animation-name background-color.'); - text: There should be one rule under @keyframes that changes the background-color to #4791d0 at 100%. testString: assert(code.match(/100%\s*?{\s*?background-color:\s*?#4791d0;\s*?}/gi), 'There should be one rule under @keyframes that changes the background-color to #4791d0 at 100%.'); ```
## Challenge Seed
```html ```
## Solution
```js // solution required ```