<section>
  <h1>Simple material design CSS only checkbox example</h1>
  <div class="md-checkbox">
    <input id="i2" type="checkbox" checked>
    <label for="i2">Item 1</label>
  </div>
  <div class="md-checkbox">
    <input id="i1" type="checkbox">
    <label for="i1">Item 2</label>
  </div>
  <div class="md-checkbox">
    <input id="i3" type="checkbox">
    <!-- Use label even if no text required -->
    <label for="i3"></label>
  </div>
  
  <div class="md-checkbox">
    <input id="i4" type="checkbox" disabled="disabled" checked>
    <label for="i4">Disabled</label>
  </div>
  <div class="md-checkbox">
    <input id="i5" type="checkbox" disabled="disabled">
    <label for="i5">Disabled</label>
  </div>
  
  <div style="text-align:center">
    <div class="md-checkbox md-checkbox-inline">
      <input id="i10" type="checkbox">
      <label for="i10">Inline & Centered</label>
    </div>
  </div>  
  
  <div>
    <p>
      Checkboxes use relative units and will scale to 
      your font size. By default the checkbox size is 
      set to 1.25em ($md-checkbox-size).
    </p>
    <div class="md-checkbox" style="font-size:20px">
      <input id="i12" type="checkbox" checked>
      <label for="i12">Scales with font size</label>
    </div>
  </div>
</section>

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

$md-checkbox-checked-color: rgb(51, 122, 183);
$md-checkbox-border-color: rgba(0, 0, 0, 0.54);
$md-checkbox-border-color-disabled: rgba(0, 0, 0, 0.26);
$md-checkbox-checked-color-disabled: rgba(0, 0, 0, 0.26);

$md-checkbox-margin: 1em 0;
$md-checkbox-size: 1.25em;
$md-checkbox-padding: .25em;
$md-checkbox-border-width: 2px;
$md-checkbox-border-radius: 0.125em;
$md-checkmark-width: 0.125em;
$md-checkmark-color: #fff;
$md-checkbox-label-padding: .75em;

.md-checkbox {
  position: relative;
  margin: $md-checkbox-margin;
  text-align: left;

  &.md-checkbox-inline {
    display: inline-block;
  }
  
  label {
    cursor: pointer;
    display: inline;
    line-height: $md-checkbox-size;
    vertical-align: top;
    clear: both;
    padding-left: 1px;
    &:not(:empty) {
      padding-left: $md-checkbox-label-padding;
    }
    
    &:before, &:after {
      content: "";
      position: absolute;
      left: 0;
      top: 0;
    }
    
    &:before {
      // box
      width: $md-checkbox-size;
      height: $md-checkbox-size;
      background: #fff;
      border: $md-checkbox-border-width solid $md-checkbox-border-color;
      border-radius: $md-checkbox-border-radius;
      cursor: pointer;
      transition: background .3s;
    }
  
    &:after {
      // checkmark
    }    
  }
  
  input[type="checkbox"] {
    outline: 0;
    visibility: hidden;
    width: $md-checkbox-size;
    margin: 0;
    display: block;
    float: left;
    font-size: inherit;

    &:checked {
       + label:before{
        background: $md-checkbox-checked-color;
        border:none;
      }
      + label:after {
        
        $md-checkmark-size: $md-checkbox-size - 2 * $md-checkbox-padding;

        transform: translate($md-checkbox-padding, ($md-checkbox-size / 2) - ($md-checkmark-size / 2.6)) rotate(-45deg);
        width: $md-checkmark-size;
        height: $md-checkmark-size / 2;
        
        border: $md-checkmark-width solid $md-checkmark-color;
        border-top-style: none;
        border-right-style: none;
      } 
    }
    
    &:disabled {
      + label:before{
        border-color: $md-checkbox-border-color-disabled;
      }
      &:checked {
        + label:before{
          background: $md-checkbox-checked-color-disabled;
        }
      }
    }
  }
 
}

// *************************************

// *************************************
*, *:before, *:after {
  box-sizing: border-box;
}

body {
  background:#f0f0f0;
  position: absolute;
  width:100%;
  padding:0;
  margin:0;
  font-family: "Roboto", sans-serif;
  color: #333;
  font-size: 16px;
}

section {
  background:white;
  margin:0 auto;
  padding: 4em;
  max-width: 800px;
  h1 {
    margin: 0 0 2em;
  }
}