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HTML

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CSS

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CSS Base

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JavaScript

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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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HTML 

              
                <p>Alege culoarea ta preferata:</p>
<div class="bkg-wrapper">
  <input name="color" class="bkg1 bkg-select" type="radio"><span class="bkg1"></span>
  <input name="color" class="bkg2 bkg-select" type="radio"><span class="bkg2"></span>
  <input name="color" class="bkg3 bkg-select" type="radio"><span class="bkg3"></span>
  <div class="bkg-container"></div>
</div>
!

CSS 

              
                /* wrapper for everything */
.bkg-wrapper{
  width:300px;
  height:300px;
  position:relative; 
}
/* div that will change background color */
.bkg-container{
  width:100%;
  height:100%;
  position:relative; 
  border-radius:4px;
  transition:0.3s ease-out;
  margin-top:10px;
  border:1px solid #000;
}
/* spans that will reprezent the input colors */
.bkg-wrapper span{
  display:inline-block;
  width:33px;
  height:33px;
  margin-left:-33px;
  pointer-events:none;
  border-radius:2px
}
.bkg1{background:#CE1126}
.bkg2{background:#FCD116}
.bkg3{background:#002B7F}

/* input styling */
.bkg-select{
  position:relative;
  width:32px;
  height:32px;
  margin-right:1px;
  cursor:pointer;
  opacity:0;
} 
.bkg-select:checked{
  opacity:0.3;
}
/* change background on checked */
input.bkg1:checked ~ .bkg-container{
  background:#CE1126;
}
input.bkg2:checked ~ .bkg-container{
  background:#FCD116;
}
input.bkg3:checked ~ .bkg-container{
  background:#002B7F;
}
!

JS
!
999px

Console