Creating Accessible Switch Controls with Pure CSS (SCSS)

A minimal CSS (SCSS)  library used to convert the standard radio buttons into accessible, nice-looking switch controls using CSS3 transitions and 3D transforms.

How to use it:

Include the SCSS into your document. You can customize the branding colors easily by changing the values in the mixins.

body { padding: 30px; }
@mixin can-toggle-branding(
  $can-toggle-off-color: #777, 
  $can-toggle-on-color: #5fc054,
  $can-toggle-inactive-text: rgba(white, 0.5),
  $can-toggle-transition: cubic-bezier(0,1,0.5,1)
) {
  
  input[type="checkbox"] {
    
    &[disabled] ~ label {
      color: rgba($can-toggle-off-color, 0.5);
    }
    
    &:focus ~ label, &:hover ~ label {
      .can-toggle__switch {
        background-color: $can-toggle-off-color;
        &:after { color: darken($can-toggle-off-color, 10%); }
      }
    }
    &:hover ~label { color: darken($can-toggle-off-color, 5%); }
    &:checked {
      ~ label {
        &:hover { color: darken($can-toggle-on-color, 3%); }
        
        .can-toggle__switch {
          background-color: lighten($can-toggle-on-color, 5%);
          &:after { color: darken($can-toggle-on-color, 5%); }
        }
      }
      
      &:focus, &:hover {
        ~ label {
          .can-toggle__switch {
            background-color: $can-toggle-on-color;
            &:after { color: darken($can-toggle-on-color, 10%); }
          }
        } 
      }
    }
  }
  
  label {
    
    .can-toggle__label-text { flex: 1; }
    
    .can-toggle__switch {
      transition: background-color 0.3s $can-toggle-transition;
      background: lighten($can-toggle-off-color, 5%);
      &:before { color: $can-toggle-inactive-text; }
      &:after {
        // Autoprefixer choked here, so making the prefixes explicit
        -webkit-transition: -webkit-transform 0.3s $can-toggle-transition;
        transition: transform 0.3s $can-toggle-transition;
        color: $can-toggle-off-color; 
      }
    }
    
  }
}
@mixin can-toggle-appearance 
( 
  $can-toggle-width: 134px,
  $can-toggle-height: 36px,
  $can-toggle-border-radius: 4px,
  $can-toggle-offset: 2px,
  $can-toggle-label-font-size: 14px,
  $can-toggle-switch-font-size: 12px,
  $can-toggle-shadow: 0 3px 3px rgba(black, 0.4)
){
  $can-toggle-switch-width: $can-toggle-width/2;
  
  input[type="checkbox"] {
    &:focus ~ label, &:hover ~ label {
      .can-toggle__switch {
        &:after { box-shadow: $can-toggle-shadow; } 
      }
    }
    
    &:checked {
      ~ label {
        .can-toggle__switch {
          &:after { transform: translate3d($can-toggle-width - ($can-toggle-switch-width + $can-toggle-offset),0,0); }  
        }
      }
      &:focus, &:hover {
        ~ label {
          .can-toggle__switch { &:after { box-shadow: $can-toggle-shadow; } }
        } 
      }
    }
  }
  
  label {
    font-size: $can-toggle-label-font-size;
    
    .can-toggle__switch {
      height: $can-toggle-height;
      flex: 0 0 $can-toggle-width;
      border-radius: $can-toggle-border-radius;
      
      &:before {
        left: $can-toggle-width/2;
        font-size: $can-toggle-switch-font-size; 
        line-height: $can-toggle-height;
        width: $can-toggle-width/2;
        padding: 0 12px;
      }
      
      &:after {
        top: $can-toggle-offset; left: $can-toggle-offset;
        border-radius: $can-toggle-border-radius/2;
        width: $can-toggle-switch-width - $can-toggle-offset; 
        line-height: $can-toggle-height - ($can-toggle-offset*2);
        font-size: $can-toggle-switch-font-size;
      }
      
      &:hover {
        &:after { box-shadow: $can-toggle-shadow; }
      }
    } 
  }
}

.can-toggle {
  position: relative;
  *, *:before, *:after { box-sizing: border-box; }
  //overflow: hidden;
  
  input[type="checkbox"] {
    opacity: 0;
    position: absolute;
    top: 0; left: 0;
    
    &[disabled] ~ label {
      pointer-events: none;
      .can-toggle__switch { opacity: 0.4; }
    }
    
    &:checked {
      ~ label {
        
        .can-toggle__switch {
          
          &:before {
            content: attr(data-unchecked);
            left: 0;
          }
        
          &:after {
            content: attr(data-checked);
          }  
        }
      }
      
      &:focus, &:hover {
        ~ label {
        } 
      }
    }
  }
  
  label {
    user-select: none;
    position: relative;
    display: flex;
    align-items: center;
    
    .can-toggle__label-text { 
      flex: 1;
      padding-left: 32px;
    }
    
    .can-toggle__switch {
      position: relative;
      
      &:before {
        content: attr(data-checked);
        position: absolute;
        top: 0;
        text-transform: uppercase;
        text-align: center;
      }
      
      &:after {
        content: attr(data-unchecked);
        position: absolute;
        z-index: 5;
        text-transform: uppercase;
        text-align: center;
        background: white;
        transform: translate3d(0,0,0);
      }
    }
    
  }
  
  // Default values for .can-toggle class
  @include can-toggle-branding; 
  @include can-toggle-appearance; 
  
  // Create toggles of different sizes by overriding the can-toggle-appearance mixin defaults
  &.can-toggle--size-small {
    @include can-toggle-appearance
    (
      90px, // Toggle width
      28px,  // Toggle height
      2px,   // Toggle border radius
      1px,   // Offset (distance btw switch and box)
      13px,  // Label font size
      10px,  // Switch font size
      0 2px 2px rgba(black, 0.4) // Switch shadow on hover/focus
    ); 
  }
  
  &.can-toggle--size-large {
    @include can-toggle-appearance
    (
      160px, // Toggle width
      50px,  // Toggle height
      4px,   // Toggle border radius
      2px,   // Offset (distance btw switch and box)
      14px,  // Label font size
      14px,  // Switch font size
      0 4px 4px rgba(black, 0.4) // Switch shadow on hover/focus
    ); 
  }
  
  // Or re-brand the toggle for different applications
  &.demo-rebrand-1 {
    @include can-toggle-branding
    (
      #b53e74,  // Off state color
      #3d9c72,  // On state color
      rgba(white, 0.6),  // Off state text color
      ease-in-out  // Transition timing function
    ); 
  }
  
  &.demo-rebrand-2 {
    @include can-toggle-branding
    (
      #444,  // Off state color
      #69be28,  // On state color
      rgba(white, 0.7),  // Off state text color
      cubic-bezier(0.860, 0.000, 0.070, 1.000)  // Transition timing function
    );
    @include can-toggle-appearance
    (
      120px, // Toggle width
      60px,  // Toggle height
      60px,   // Toggle border radius
      2px,   // Offset (distance btw switch and box)
      13px,  // Label font size
      13px,  // Switch font size
      0 4px 4px rgba(black, 0.4) // Switch shadow on hover/focus
    ); 
  }
  
}

The markup.

<div class="can-toggle">
  <input id="a" type="checkbox">
  <label for="a">
    <div class="can-toggle__switch" data-checked="On" data-unchecked="Off"></div>
    <div class="can-toggle__label-text">.can-toggle</div>
  </label>
</div>
<br>
<div class="can-toggle can-toggle--size-small">
  <input id="b" type="checkbox">
  <label for="b">
    <div class="can-toggle__switch" data-checked="On" data-unchecked="Off"></div>
    <div class="can-toggle__label-text">.can-toggle.can-toggle--size-small</div>
  </label>
</div>
<br>
<div class="can-toggle can-toggle--size-large">
  <input id="c" type="checkbox">
  <label for="c">
    <div class="can-toggle__switch" data-checked="On" data-unchecked="Off"></div>
    <div class="can-toggle__label-text">.can-toggle.can-toggle--size-large</div>
  </label>
</div>
<br>
<div class="can-toggle demo-rebrand-1">
  <input id="d" type="checkbox">
  <label for="d">
    <div class="can-toggle__switch" data-checked="Good" data-unchecked="Bad"></div>
    <div class="can-toggle__label-text">.can-toggle.demo-rebrand-1</div>
  </label>
</div>
<br>
<div class="can-toggle demo-rebrand-2">
  <input id="e" type="checkbox">
  <label for="e">
    <div class="can-toggle__switch" data-checked="Yes" data-unchecked="No"></div>
    <div class="can-toggle__label-text">.can-toggle.demo-rebrand-2</div>
  </label>
</div>