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<div class="container">
<div class="toggle">
<input type="checkbox">
<span class="button"></span>
<span class="label">+</span>
</div>
<div class="toggle">
<input type="checkbox" checked>
<span class="button"></span>
<span class="label">–</span>
</div>
</div>
@import compass
// Squishy buttons inspired by https://goo.gl/bFCyS
@import url(https://fonts.googleapis.com/css?family=Lato:700)
html, body
font-family: 'Lato', sans-serif
background: url(https://s.cdpn.io/1715/dark_stripes.png)
text-align: center
height: 100%
.container
text-align: center
position: absolute
margin-top: -80px
width: 100%
top: 50%
.toggle
margin: 4px
display: inline-block
.toggle
$size: 140px
box-shadow: inset 0 0 35px 5px rgba(0,0,0,0.25), inset 0 2px 1px 1px rgba(255,255,255,0.9), inset 0 -2px 1px 0 rgba(0,0,0,0.25)
border-radius: 8px
background: #ccd0d4
position: relative
height: $size
width: $size
&:before
$radius: $size * 0.845
$glow: $size * 0.125
box-shadow: 0 0 $glow $glow / 2 #fff
border-radius: $radius
background: #fff
position: absolute
margin-left: ( $radius - $glow ) * -0.5
margin-top: ( $radius - $glow ) * -0.5
opacity: 0.2
content: ''
height: $radius - $glow
width: $radius - $glow
left: 50%
top: 50%
.button
$radius: $size * 0.688
-webkit-filter: blur(1px)
-moz-filter: blur(1px)
filter: blur(1px)
transition: all 300ms cubic-bezier(0.230, 1.000, 0.320, 1.000)
box-shadow: 0 15px 25px -4px rgba(0,0,0,0.5), inset 0 -3px 4px -1px rgba(0,0,0,0.2), 0 -10px 15px -1px rgba(255,255,255,0.6), inset 0 3px 4px -1px rgba(255,255,255,0.2), inset 0 0 5px 1px rgba(255,255,255,0.8), inset 0 20px 30px 0 rgba(255,255,255,0.2)
border-radius: $radius
position: absolute
background: #ccd0d4
margin-left: $radius * -0.5
margin-top: $radius * -0.5
display: block
height: $radius
width: $radius
left: 50%
top: 50%
.label
transition: color 300ms ease-out
text-shadow: 1px 1px 3px #ccd0d4, 0 0 0 rgba(0,0,0,0.8), 1px 1px 4px #fff
line-height: $size - 1
text-align: center
position: absolute
font-weight: 700
font-size: 42px
display: block
opacity: 0.9
height: 100%
width: 100%
color: rgba(0,0,0,0.4)
input
opacity: 0
background :red
position: absolute
cursor: pointer
z-index: 1
height: 100%
width: 100%
left: 0
top: 0
&:active
~ .button
box-shadow: 0 15px 25px -4px rgba(0,0,0,0.4), inset 0 -8px 30px 1px rgba(255,255,255,0.9), 0 -10px 15px -1px rgba(255,255,255,0.6), inset 0 8px 25px 0 rgba(0,0,0,0.4), inset 0 0 10px 1px rgba(255,255,255,0.6)
~ .label
font-size: 40px
color: rgba(0,0,0,0.45)
&:checked
~ .button
box-shadow: 0 15px 25px -4px rgba(0,0,0,0.4), inset 0 -8px 25px -1px rgba(255,255,255,0.9), 0 -10px 15px -1px rgba(255,255,255,0.6), inset 0 8px 20px 0 rgba(0,0,0,0.2), inset 0 0 5px 1px rgba(255,255,255,0.6)
~ .label
font-size: 40px
color: rgba(0,0,0,0.4)
Also see: Tab Triggers