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HTML

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HTML preprocessors can make writing HTML more powerful or convenient. For instance, Markdown is designed to be easier to write and read for text documents and you could write a loop in Pug.

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CSS

About CSS Preprocessors

CSS preprocessors help make authoring CSS easier. All of them offer things like variables and mixins to provide convenient abstractions.

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CSS Base

About CSS Base

It's a common practice to apply CSS to a page that styles elements such that they are consistent across all browsers. We offer two of the most popular choices: normalize.css and a reset. Or, choose Neither and nothing will be applied.

Vendor Prefixing

About Vendor Prefixing

To get the best cross-browser support, it is a common practice to apply vendor prefixes to CSS properties and values that require them to work. For instance -webkit- or -moz-.

We offer two popular choices: Autoprefixer (which processes your CSS server-side) and -prefix-free (which applies prefixes via a script, client-side).

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JavaScript

About JavaScript Preprocessors

JavaScript preprocessors can help make authoring JavaScript easier and more convenient. For instance, CoffeeScript can help prevent easy-to-make mistakes and offer a cleaner syntax and Babel can bring ECMAScript 6 features to browsers that only support ECMAScript 5.

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Babel is required to process package imports. If you need a different preprocessor remove all packages first.

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You can apply a script from anywhere on the web to your Pen. Just put a URL to it here and we'll add it, in the order you have them, before the JavaScript in the Pen itself.

If the script you link to has the file extension of a preprocessor, we'll attempt to process it before applying.

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HTML 

              
                <form>
	<input class="ch" type="checkbox" name="temperature" value="is_hot">
</form>
!

CSS 

              
                *, *:before, *:after {
	box-sizing: border-box;
	margin: 0;
	padding: 0;
}
:root {
	font-size: calc(16px + (24 - 16) * (100vw - 320px)/(1600 - 320));
}
body {
	background: rgb(235,167,49);
	line-height: 1.5;
}
input {
	display: inline-block;
}
form {
	padding: 3em 1.5em 0 1.5em;
	text-align: center;	
}
.ch, .ch:before, .ch:after {
	transition: all 0.3s ease-in-out;
}
.ch {
	background-color: rgb(27,123,145);
	border-radius: 0.2em;
	box-shadow: 0 0.05em 0 0.05em rgba(0,0,0,0.3) inset;
	font-size: 4em;
	overflow: hidden;
	position: relative;
	width: 3em;
	height: 1.5em;
	-webkit-appearance: none;
	-moz-appearance: none;
	appearance: none;
	z-index: 0;
}
.ch:before, .ch:after {
	content: "";
	display: block;
	position: absolute;
}
.ch:before {
	background-color: currentColor;
	border-radius: 0.125em;
	box-shadow:
		0 0 0 0.05em inset,
		-0.12em -0.12em 0 rgb(109,148,184) inset,
		-0.4em -0.3em 0 0.05em inset,
		0.12em 0.12em 0 rgb(255,255,255) inset;
	color: rgb(149,188,224);
	opacity: 0.9;
	bottom: 0;
	left: 0.125em;
	width: 1.25em;
	height: 1.25em;
	z-index: 2;
}
.ch:after {
	background-image:
		/* white */
		radial-gradient(0.2em 0.5em at 38% 95%, rgb(255,255,255) 49%, rgba(255,255,255,0) 50%),
		radial-gradient(0.3em 0.8em at 52% 95%, rgb(255,255,255) 49%, rgba(255,255,255,0) 50%),
		radial-gradient(0.25em 0.4em at 67% 95%, rgb(255,255,255) 49%, rgba(255,255,255,0) 50%),
		/* yellow */
		radial-gradient(0.25em 0.7em at 36% 95%, rgb(255,224,0) 49%, rgba(255,224,0,0) 50%),
		radial-gradient(0.4em 1.2em at 52% 95%, rgb(255,224,0) 49%, rgba(255,224,0,0) 50%),
		radial-gradient(0.25em 0.6em at 70% 93%, rgb(255,224,0) 49%, rgba(255,224,0,0) 50%),
		/* orange */
		radial-gradient(0.3em 0.8em at 32% 81%, rgb(255,144,0) 49%, rgba(255,144,0,0) 50%),
		radial-gradient(0.5em 1.6em at 52% 95%, rgb(255,144,0) 49%, rgba(255,144,0,0) 50%),
		radial-gradient(0.3em 0.9em at 74% 86%, rgb(255,144,0) 49%, rgba(255,144,0,0) 50%),
		/* red-orange */
		radial-gradient(0.4em 1em at 25% 70%, rgb(255,76,0) 49%, rgba(255,76,0,0) 50%),
		radial-gradient(0.7em 2.75em at 52% 100%, rgb(255,76,0) 49%, rgba(255,76,0,0) 50%),
		radial-gradient(0.4em 1.2em at 79% 75%, rgb(255,76,0) 49%, rgba(255,76,0,0) 50%);

	background-position: 100% 1.5em;
	background-size: 1.5em 1.5em;
	background-repeat: no-repeat;
	border-radius: 0 0 0 0.1em / 0 0 0 0;
	box-shadow: 0 0 0 0 rgb(169,208,244) inset;
	bottom: 0;
	left: 0;
	width: 1.5em;
	height: 1.5em;
	z-index: 1;
}
/* Checked */
.ch:checked {
	background-color: rgb(92,8,8);
}
.ch:checked:before {
	border-radius: 50%;
	transform: translate(1.5em,1.5em) rotate(45deg) scale(0.5);
}
.ch:checked:after {
	background-position: 100% 0;
	box-shadow: 0 -0.15em 0 0 rgb(169,208,244) inset;
	width: 3em;
}

/* Other States */
.ch:focus {
	/* Usually an anti-A11Y practice but set to remove an annoyance just for this demo */
	outline: 0;
}
!

JS
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999px

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