@angular2-material/button/_button-theme.scss

/** Applies a property to an md-button element for each of the supported palettes. */
@mixin md-button-theme($property, $color: 'default', $opacity: 1) {
  &.md-primary {
    #{$property}: md-color($md-primary, $color, $opacity);
  }
  &.md-accent {
    #{$property}: md-color($md-accent, $color, $opacity);
  }
  &.md-warn {
    #{$property}: md-color($md-warn, $color, $opacity);
  }

  &.md-primary, &.md-accent, &.md-warn, &[disabled] {
    &[disabled] {
      $palette: if($property == 'color', $md-foreground, $md-background);
      #{$property}: md-color($palette, disabled-button);
    }
  }
}

/** Applies a focus style to an md-button element for each of the supported palettes. */
@mixin md-button-focus {
  &::after {
    // The button spec calls for focus on raised buttons (and FABs) to be indicated with a
    // black, 12% opacity shade over the normal color (for both light and dark themes).
    // We do this by placing an :after psuedo-element with the appropriate shade over the button.
    position: absolute;
    top: 0;
    left: 0;
    bottom: 0;
    right: 0;
    content: '';
    background-color: rgba(black, 0.12);
    border-radius: inherit;
    pointer-events: none;
  }

  &.md-primary::after {
    background-color: md-color($md-primary, 0.12);
  }

  &.md-accent::after {
    background-color: md-color($md-accent, 0.12);
  }

  &.md-warn::after {
    background-color: md-color($md-warn, 0.12);
  }
}