ionic-framework/scss/ionic/_button.scss

.button {
  position: relative;
  display: inline-block;
  margin: 0;

  padding: $button-padding;
  min-height: $button-min-height;

  border-width: $button-border-width;
  border-style: solid;
  border-radius: $button-border-radius;

  color: $button-color;
  vertical-align: top;

  text-align: center;

  text-overflow: ellipsis;
  font-size: $button-font-size;
  line-height: $button-line-height;

  cursor: pointer;

  [class^="icon-"], 
  [class*=" icon-"] {
    display: inline-block;
    padding: 0;
    vertical-align: inherit;
    font-size: $button-icon-font-size;
    line-height: $button-line-height - 1;
  }

  &.button-icon {
    padding: $button-clear-padding;
    background: none;

    [class^="icon-"], 
    [class*=" icon-"] {
      font-size: $button-icon-large-font-size;
    }
  }

  &.button-clear {
    @include transition(opacity .1s);
    padding: $button-clear-padding;
    border: none;
    background: none;
    box-shadow: none;

    &:active, &.active {
      opacity: 0.3;
    }
  }

  &.button-default {
    @include button-style($button-default-bg, $button-default-border, $button-default-active-bg, $button-default-active-border, $gray-dark);
    @include button-clear($button-default-border);
    @include button-outline($button-default-border, $gray-dark);
  }
  &.button-secondary {
    @include button-style($button-secondary-bg, $button-secondary-border, $button-secondary-active-bg, $button-secondary-active-border, $gray-dark);
    @include button-clear($button-secondary-border);
    @include button-outline($button-secondary-border, $gray-dark);
  }
  &.button-primary {
    @include button-style($button-primary-bg, $button-primary-border, $button-primary-active-bg, $button-primary-active-border, $white);
    @include button-clear($button-primary-bg);
    @include button-outline($button-primary-bg);
  }
  &.button-info {
    @include button-style($button-info-bg, $button-info-border, $button-info-active-bg, $button-info-active-border, $white);
    @include button-clear($button-info-bg);
    @include button-outline($button-info-bg);
  }
  &.button-success {
    @include button-style($button-success-bg, $button-success-border, $button-success-active-bg, $button-success-active-border, $white);
    @include button-clear($button-success-bg);
    @include button-outline($button-success-bg);
  }
  &.button-warning {
    @include button-style($button-warning-bg, $button-warning-border, $button-warning-active-bg, $button-warning-active-border, $white);
    @include button-clear($button-warning-bg);
    @include button-outline($button-warning-bg);
  }
  &.button-danger {
    @include button-style($button-danger-bg, $button-danger-border, $button-danger-active-bg, $button-danger-active-border, $white);
    @include button-clear($button-danger-bg);
    @include button-outline($button-danger-bg);
  }
  &.button-dark {
    @include button-style($button-dark-bg, $button-dark-border, $button-dark-active-bg, $button-dark-active-border, $white);
    @include button-clear($button-dark-bg);
    @include button-outline($button-dark-bg);
  }

  &.button-outline {
    @include transition(opacity .1s);
    background: none;
    box-shadow: none;
  }

  &.button-icon {
    border: none;
    background: none;
    &:active, &.active {
      background: none;
      box-shadow: none;
      text-shadow: 0px 0px 10px #fff;
    }
  }

  &.block, &.button-full {
    margin-top: $button-block-margin;
    margin-bottom: $button-block-margin;
  }

}

.button-small {
  font-size: $button-font-size - 4;
  min-height: 32px;
  padding: 1px 8px 1px 8px;

  [class^="icon-"], 
  [class*=" icon-"] {
    font-size: $button-icon-font-size - 4;
  }
}

.button-large {
  font-size: $button-font-size + 8;
  min-height: $button-min-height + 8;
  padding: 12px 18px 12px 18px;

  [class^="icon-"], 
  [class*=" icon-"] {
    font-size: $button-icon-font-size + 8;
  }
}

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

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

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

a.button {
  text-decoration: none;
}