JavaScript Spotlight Effect on Mousemove

02/19/2021

Contents

Demo

Full Screen

Code

HTML

<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width,initial-scale=1">
    <title>Spotlight Effect</title>
    <link rel="stylesheet" type="text/css" href="https://demo.plantpot.works/assets/css/normalize.css">
    <link rel="stylesheet" href="https://use.typekit.net/opg3wle.css">
    <link rel="stylesheet" type="text/css" href="style.css">
  </head>
  <body>
    <div id="container">
      <div id="spotlight" class="spotlight">
        <h1>Spotlight Effect<br>on Mousemove</h1>
      </div>
    </div>
  </body>
</html>

CSS

@charset "utf-8";
* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}
html {
  font-size: 16px;
}
body {
  font-family: futura-pt, sans-serif;
  -webkit-tap-highlight-color: rgba(0,0,0,0);
	cursor: none;
}
#container {
	position: relative;
  width: 100%;
  height: 100vh;
	background-image: url(bg.jpg);
	background-position: center;
	background-size: cover;
	background-repeat: no-repeat;
}
.spotlight {
	display: flex;
	justify-content: center;
	align-items: center;
	position: absolute;
	width: 100%;
	height: 100%;
	background-image: radial-gradient(circle, transparent 40px, rgba(0, 0, 0, .8) 55px);
}
h1 {
  margin: 0;
  color: #fff;
  font-size: 3rem;
  letter-spacing: 1px;
  text-align: center;
}
@media screen and (max-width: 480px) {
  h1 {
    font-size: 2rem;
  }
}

JavaScript

var spotlight = document.getElementById("spotlight");
window.addEventListener('mousemove', e => {
spotlight.style.backgroundImage = "radial-gradient(circle at " + e.clientX + "px " + e.clientY + "px, transparent 40px, rgba(0, 0, 0, .8) 55px)";