ionic-framework/ionic/components/button/button.scss

// Core Button Variables
// --------------------------------------------------

$button-font-size:                1.4rem !default;
$button-margin:                   0.4rem 0 !default;
$button-padding:                  0 1.4rem !default;
$button-height:                   4.2rem !default;
$button-border-width:             1px !default;
$button-border-radius:            4px !default;
$button-icon-size:                3rem !default;

$button-large-font-size:          2rem !default;
$button-large-height:             5.4rem !default;
$button-large-padding:            1.4rem !default;
$button-large-icon-size:          3.6rem !default;

$button-small-font-size:          1.3rem !default;
$button-small-height:             2.8rem !default;
$button-small-padding:            1.1rem !default;
$button-small-icon-size:          2.1rem !default;


// Core Button
// --------------------------------------------------

.button {
  position: relative;

  display: inline-flex;
  flex-shrink: 0;
  flex-flow: row nowrap;
  align-items: center;
  justify-content: center;
  z-index: $z-index-button;

  margin: $button-margin;
  line-height: 1;

  @include appearance(none);

  vertical-align: top; // the better option for most scenarios
  vertical-align: -webkit-baseline-middle; // the best for those that support it

  font-family: inherit;
  font-variant: inherit;
  font-style: inherit;

  white-space: nowrap;
  text-overflow: ellipsis;
  overflow: hidden;

  cursor: pointer;
  user-select: none;

  &:after {
    // used to create a larger button "hit" area
    position: absolute;
    top: -6px;
    right: -6px;
    bottom: -6px;
    left: -6px;
    content: ' ';
  }
}


// Core Button Styling
// --------------------------------------------------

.button {
  border: 1px solid #ccc;
  padding: $button-padding;
  min-height: $button-height;
  background: #fff;

  text-align: center;
  font-size: $button-font-size;
  border: transparent;
  border-radius: $button-border-radius;

  &.button-icon {
    font-size: $button-icon-size;
  }

  &.button-large {
    padding: 0 $button-large-padding;
    min-width: ($button-large-padding * 4);
    min-height: $button-large-height;
    font-size: $button-large-font-size;

    &.button-icon {
      font-size: $button-large-icon-size;
    }
  }

  &.button-small {
    padding: 0 $button-small-padding;
    min-width: ($button-small-padding * 3);
    min-height: $button-small-height;
    font-size: $button-small-font-size;

    &.button-icon {
      font-size: $button-small-icon-size;
    }
  }
}


// Core Button Types
// --------------------------------------------------

.button-clear {
  border-color: transparent;
  background: none;

  &.activated {
    opacity: 0.3;
  }
}

.button-outline {
  background: none;
}

.button-block {
  display: flex;
  clear: both;
  margin-right: 0;
  margin-left: 0;

  &:after {
    clear: both;
  }
}

.button-full,
.button-full > .button {
  display: flex;
  margin-right: 0;
  margin-left: 0;
  border-radius: 0;

  &.button-outline.button-outline {
    border-right-width: 0;
    border-left-width: 0;
  }
}

button.button-block,
button.button-full,
.button-full > button.button,
input.button.button-block  {
  width: 100%;
}

.padding > .button.button-block:first-child {
  margin-top: 0;
}

.icon-left:before {
  font-size: 1.5em;
  margin-top: -0.1em;
  margin-right: 0.25em;
}

.icon-right:before {
  order: 2;
  font-size: 1.5em;
  margin-top: -0.1em;
  margin-left: 0.25em;
}


// Button Misc
// --------------------------------------------------

a.button {
  text-decoration: none;
}

.button.disabled,
.button[disabled] {
  opacity: .4;
  cursor: default !important;
  pointer-events: none;
}


// Core Button Mixins
// --------------------------------------------------

@mixin button-default($bg-color, $fg-color) {
  background-color: $bg-color;
  color: $fg-color;

  &:hover,
  &.hover {
    opacity: 0.88;
    color: $fg-color;
    text-decoration: none;
  }

  &.activated {
    opacity: 1;
    background-color: darken($bg-color, 12%);
  }
}

@mixin button-clear($fg-color) {
  &.button-clear {
    background: none;
    color: $fg-color;
  }
}

@mixin button-outline($fg-color) {
  &.button-outline {
    border: 1px solid $fg-color;
    background: transparent;
    color: $fg-color;

    &.activated {
      background-color: rgba(red($fg-color), green($fg-color), blue($fg-color), 0.15);
    }
  }
}


// Core Button Color Generation
// --------------------------------------------------

@each $color, $value in $colors {

  .button-#{$color} {
    @include button-default(get-color($color, base),
                            get-color($color, inverse));

    @include button-clear(get-color($color, base));

    @include button-outline(get-color($color, base));
  }

}