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Theme Toggle Animation in Pure CSS

Theme Toggle Animation in Pure CSS

Shikhar Baniya's photo
Shikhar Baniya
·

3 min read

Hello Coders! Welcome to CSS Animation Blog. In this, we're going to see how to create a theme toggle which allows you to change light and dark mode by a click of a toggle in Pure CSS. Dark mode is now a trend in Website Design and Developers are also adding a dark mode feature in all the webapps. This is a sample version of the same. You can see the body having title and paragraph. On top of it, there is a toggle which allows us to change the theme of the window. Hope you'll like it.

Here's a preview-

CodePen-theme-toggle.gif

That being said, let us get started.

Step - 1: Like always, create 2 files - index.html and style.css.

Step - 2: Copy the below HTML code and paste it into your code editor.

HTML


<!DOCTYPE html>
<html lang="en" >
<head>
  <meta charset="UTF-8">
  <title>theme-toggle</title>
  <meta name="viewport" content="width=device-width, initial-scale=1">
<link rel="stylesheet" href="./style.css">

</head>
<body>

<body>
  <div class="container">
    <h1>This is title</h1>
    <div class="toggle-container">
      <input type="checkbox" id="switch" name="theme" /><label for="switch" id="toggle">Toggle</label>
    </div>
    <p>Lorem ipsum dolor, sit amet consectetur adipisicing elit. Architecto, sed. Minima distinctio consequatur aperiam quo ratione hic, neque quisquam nulla. Alias eum, quicksand quidem corporis accusamus fugit cumque fugiat modi?</p>
  </div>
</body>

  <script  src="./script.js"></script>

</body>
</html>

Step - 3: Below is the CSS code for styling.

CSS

@import url("https://fonts.googleapis.com/css?family=Quicksand");

html {
  height: 70%;
  font-family: 'Quicksand', sans-serif;
  display: -ms-grid;
  display: grid;
  align-items: center;
  justify-content: center;

  /* settings for light theme,
  vanilla css variables */
  --bg: #ffffff;
  --bg-panel: #ffffff;
  --color-heading: #0077FF;
  --color-text: #6d6d6d;
  --color-toggle-border: #dadada;
  --color-toggle: #b1b1b1;
}

/* remove focus outline */
*:focus {
  outline: none;
}

html .container {
  box-shadow: 0px 45px 133px -25px rgba(0, 0, 0, 0.1);
}

/* settings for dark theme */
html[data-theme="dark"] {
  --bg: #23272b;
  --bg-panel: #16191c;
  --color-heading: #3694FF;
  --color-text: rgb(102, 102, 102);
  --color-toggle-border: #353535;
  --color-toggle: #525252;
}

html[data-theme="dark"] .container {
  box-shadow: 0px 45px 133px -25px rgba(0, 0, 0, 0);
}

body {
  background-color: var(--bg);
}
.container {
  background-color: var(--bg-panel);
  margin: 5em;
  padding: 5em;
  border-radius: 10px;
  max-width: 800px;
  display: -ms-grid;
  display: grid;
  -ms-grid-columns: 80% auto;
  grid-template-columns: 80% auto;
  -ms-grid-rows: auto auto;
  grid-template-rows: auto auto;
  grid-template-areas: "title switch" "content content";
}
.container h1 {
  margin: 0;
  color: var(--color-heading);
}
.container p {
  color: var(--color-text);
  -ms-grid-row: 2;
  -ms-grid-column: 1;
  -ms-grid-column-span: 2;
  grid-area: content;
  font-size: 1.1em;
  line-height: 1.8em;
  margin-top: 2em;
}

/* toggle switch */
input[type=checkbox] {
  height: 0;
  width: 0;
  visibility: hidden;
}
label {
  cursor: pointer;
  border-style: solid;
  border-color: var(--color-toggle-border);
  text-indent: -9999px;
  width: 52px;
  height: 26px;
  background: var(--bg-panel);
  float: right;
  border-radius: 100px;
  position: relative;
  transition: 0.5s;
}
label:after {
  content: '';
  position: absolute;
  top: 4px;
  left: 4px;
  width: 18px;
  height: 18px;
  background: var(--color-toggle);
  border-radius: 90px;
}
input:checked+label {
  background: var(--bg-panel);
}

input:checked+label:after {
  left: calc(100% - 4px);
  transform: translateX(-100%);
}

/* transitions */

html.transition,
html.transition *,
html.transition *:before,
html.transition *:after {
  transition: all 750ms !important;
  transition-delay: 0 !important;
}

@media only screen and (max-width: 600px) {
  .container {
    margin: 2em;
    padding: 2em;
  }
}

Step - 3: Below is the JS code for applying the toggle functionality.

JS

const checkbox = document.querySelector('input[name=theme]');
setThemeOnLoad();

checkbox.addEventListener('change', function() {
  let value;

  if (this.checked) {
      transition();
      document.documentElement.setAttribute('data-theme', 'dark');
      value = 'dark';
  } else {
      transition();
      document.documentElement.setAttribute('data-theme', 'light');
      value = 'light';
  }
  // save theme value
  localStorage.setItem('data-theme', value);
});
// get previously applied theme
function setThemeOnLoad() {
  let theme = localStorage.getItem('data-theme');

  if (theme === 'dark') {
    document.documentElement.setAttribute('data-theme', 'dark');
    // set toggle state
    checkbox.checked = true;
  } else {
      document.documentElement.setAttribute('data-theme', 'light');
    }
}
let transition = () => {
  document.documentElement.classList.add('transition');
  document.documentElement.addEventListener('animationend', () => {
    this.classList.remove('transition');
  });
}

And that's it. You're done.

Let me know in the comments if you have any doubt related to this.

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