HTML-CSS: Mouse cursor gradient tracking

HTML-CSS : Exercise-8 with Solution

Using HTML, CSS, JavaScript create a hover effect where the gradient follows the mouse cursor.

  • Declare two CSS variables, --x and --y, used to track the position of the mouse on the button.
  • Declare a CSS variable, --size, used to modify the gradient's dimensions.
  • Use background: radial-gradient(circle closest-side, pink, transparent); to create the gradient at the correct position.
  • Use Document.querySelector() and EventTarget.addEventListener() to register a handler for the 'mousemove' event.
  • Use Element.getBoundingClientRect() and CSSStyleDeclaration.setProperty() to update the values of the --x and --y CSS variables.

HTML Code:

<!--License: https://bit.ly/3GjrtVF-->
<!DOCTYPE html>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width">
  <title>Using HTML, CSS, JavaScript create a hover effect where the gradient follows the mouse cursor</title>
<button class="mouse-cursor-gradient-tracking">
  <span>Hover me</span></button>

CSS Code:


.mouse-cursor-gradient-tracking {
  position: relative;
  background: #7983ff;
  padding: 0.5rem 1rem;
  font-size: 1.2rem;
  border: none;
  color: white;
  cursor: pointer;
  outline: none;
  overflow: hidden;

.mouse-cursor-gradient-tracking span {
  position: relative;

.mouse-cursor-gradient-tracking:before {
  --size: 0;
  content: '';
  position: absolute;
  left: var(--x);
  top: var(--y);
  width: var(--size);
  height: var(--size);
  background: radial-gradient(circle closest-side, red, transparent);
  transform: translate(-50%, -50%);
  transition: width 0.2s ease, height 0.2s ease;

.mouse-cursor-gradient-tracking:hover:before {
  --size: 200px;


JavaScript Code:

let btn = document.querySelector('.mouse-cursor-gradient-tracking');
btn.addEventListener('mousemove', e => {
  let rect = e.target.getBoundingClientRect();
  let x = e.clientX - rect.left;
  let y = e.clientY - rect.top;
  btn.style.setProperty('--x', x + 'px');
  btn.style.setProperty('--y', y + 'px');


HTML-CSS Editor:

See the Pen html-css-practical-exercises by w3resource (@w3resource) on CodePen.

What is the difficulty level of this exercise?

Test your Programming skills with w3resource's quiz.

HTML-CSS: Tips of the Day

How can I show dots ("...") in a span with hidden overflow?

For this you can use text-overflow: ellipsis; property. Write like this

span {
    display: inline-block;
    width: 180px;
    white-space: nowrap;
    overflow: hidden !important;
    text-overflow: ellipsis;
<span>Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book</span>

Ref: https://bit.ly/2RqEbdh