main
  header
    h1 "Material Design" Animated Buttons
    a(href="twitter.com/jonbrennecke") by @jonbrennecke
  section.col
    div.button.clickable
      input(type="checkbox").toggle
      div.anim
      span Click!
    div.button.hoverable
      div.anim
      span Hover!
  section.col
    div.button.raised.clickable
      input(type="checkbox").toggle
      div.anim
      span Click!
    div.button.raised.hoverable
      div.anim
      span Hover!

@import "compass/css3";

// Compass!
@import "compass/reset";
@import "compass/css3/animation";
@import "compass/css3/appearance";
@import "compass/css3/transition";

// Robot from Google Fonts
@import url(https://fonts.googleapis.com/css?family=Roboto:400,100,300,500);

// Background and foreground colors
$bg-color: #2196F3;
$fg-color: darken($bg-color,7%);

// Penner easing equation via http://matthewlein.com/ceaser/
$easeOutQuad: cubic-bezier(0.250, 0.460, 0.450, 0.940);

body {
  font-family: Roboto, sans-serif;
  background: $bg-color;
  font-size: 16pt;
  color: lighten($bg-color,15%);
  font-weight: 200;
  padding: 2em;
}

.col {
  display: inline-block;
  vertical-align: top;
}

main {
  @include transform(translateX(-50%));
  position: relative;
  display: inline-block;
  left: 50%;
  
  header {
    color: #fff;
    text-align: center;
    margin: 1em;
    h1 {
      font-size: 1.25em;
      margin: 0.25em;
    }
    a {
      color: lighten($bg-color,15%);
      text-decoration: none;
    }
  }
}
  
.button {
  position: relative;
  margin: 1em;
  font-weight: 100;
  padding: 1em 1.25em;
  text-align: center;
  width: 200px;
  border-radius: 5px;
  overflow: hidden;
  position: relative;
  z-index: 0;
  cursor: pointer;
  
  &.raised {
    @include transition(0.1s all);
    background: $fg-color;
    box-shadow: 0px 1px 1px darken($fg-color,15%);
    &:active {
      background: darken($fg-color,2.5%);
      box-shadow: 0px 1px 1px darken($fg-color,25%);
    }
  }
}


span {
  font-weight: 400;
}

input[type="checkbox"].toggle {
  @include appearance(none);
  position: absolute;
  width: 100%;
  height: 100%;
  margin: 0;
  left: 0;
  top: 0;
  cursor: pointer;
  
  &:focus {
    outline: 0; // Get rid of Chrome's ugly outline on focus
  }
}

.anim {
  @include transform(translateY(-50%) translateX(-50%));
  position: absolute;
  top: 50%;
  left: 50%;
  z-index: -1;

  // The ':before' psuedo element is a spacing ghost to make the 
  // ':after' psuedo element a square, with width & height 
  // automatically equal to the parent's width.
  &:before {
    position: relative;
    content: '';
    display: block;
    margin-top: 100%;
  }
  
  &:after {
    content: '';
    position: absolute;
    top: 0;
    bottom:0;
    left: 0;
    right: 0;
    border-radius: 50%;
  }
}

.clickable {
  .toggle:checked + .anim {
    @include animation(anim-in 0.75s);
    &:after { @include animation(anim-in-pseudo 0.75s); }
  }

  .toggle:not(:checked) + .anim {
    @include animation(anim-out 0.75s);
    &:after { @include animation(anim-out-pseudo 0.75s); }
  }  
}

.hoverable:hover > .anim {
  @include animation(anim-out 0.75s);
  &:after { @include animation(anim-out-pseudo 0.75s); }
}

// Keyframes mixin
@mixin keyframes($name) {
	@-webkit-keyframes #{$name} {
		@content; 
	}
	@-moz-keyframes #{$name} {
		@content;
	}
	@-ms-keyframes #{$name} {
		@content;
	}
	@keyframes #{$name} {
		@content;
	} 
}

@include keyframes(anim-in) {
  0% { width: 0%; }
  100% { width: 100%; }
}

@include keyframes(anim-in-pseudo) {
  0% { background: rgba(#000,0.25); }
  100% { background: rgba(#000,0); }
}

@include keyframes(anim-out) {
  0% { width: 0%; }
  100% { width: 100%; }
}

@include keyframes(anim-out-pseudo) {
  0% { background: rgba(#000,0.25); }
  100% { background: rgba(#000,0); }
}

/**
 * Nothing to see here!
 *
 */