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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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Insecure Resource

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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.

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Babel includes JSX processing.

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Packages

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Search for and use JavaScript packages from npm here. By selecting a package, an import statement will be added to the top of the JavaScript editor for this package.

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Using packages here is powered by Skypack, which makes packages from npm not only available on a CDN, but prepares them for native JavaScript ES6 import usage.

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HTML 

              
                main
  .fill-area
  label#range-value(for="range") 0
  input#range(type="range", name="range", value="0", min="0", max="100" onmousemove="handleMouseMove(this.value)" onchange="handleMouseMove(this.value)")
!

CSS 

              
                @import url('https://fonts.googleapis.com/css2?family=Monoton&display=swap')

* 
  margin 0
  padding 0
  box-sizing border-box
  
main
  display flex
  flex-flow column nowrap
  justify-content center
  align-items center
  width 100vw
  height 100vh
  background linear-gradient(to right, #ff5c5c, #ffa860, #e3dc44, #57b02a)
  
.fill-area  
  position absolute
  top 0
  left 0
  z-index 0
  width 100vw
  height 100vh
  background #333838
  box-shadow inset 3px 3px 5px -1px #111
  pointer-events none
  
label
  position static
  z-index 1
  font 8rem "Monoton", sans-serif
  color #EC7474
  margin -5rem 0 2rem
  
label::after
  content "%"
  
input[type=range]
  position static
  z-index 2
  width 50vw
  height 1rem
  background rgba(#582424, 0.8)
  appearance none
  border none
  outline none
  border-radius 100vmax
  box-shadow inset 3px 3px 5px -1px #000
  
input[type=range]::-webkit-slider-thumb
  appearance none
  width 4vw
  height 4vw
  background #eee
  border-radius 50%
  cursor pointer
  box-shadow 5px 5px 8px -1px #000
  transition box-shadow .3s ease-in-out
  
input[type=range]:hover::-webkit-slider-thumb
  background #fff
  box-shadow 3px 3px 5px -1px #000
  
input[type=range]::-ms-track
  width 100%
  background transparent; 
  border-color transparent;
  color transparent;
  
@media screen and (max-width: 532px)
  label
    font-size: 24vw
!

JS 

              
                function handleMouseMove(value) {
  const rangeValueElement = document.querySelector("#range-value")
  const inputElement = document.querySelector('input[type="range"]')
  const fillAreaElement = document.querySelector(".fill-area")
  
  const hueRotate = "hue-rotate(" + value + "deg)"
  
  rangeValueElement.textContent = value
  rangeValueElement.style.filter = hueRotate
  
  inputElement.style.filter = hueRotate
  
  fillAreaElement.style.left = value + "vw"
  fillAreaElement.style.width = (100-value) + "vw"
  fillAreaElement.style.filter = hueRotate
}
!
999px

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