node_modules/@angular/material/button/_button-theme.scss

@import '../core/theming/theming';
@import '../core/style/private';
@import '../core/typography/typography-utils';

$_mat-button-ripple-opacity: 0.1;

// Applies a focus style to an mat-button element for each of the supported palettes.
@mixin _mat-button-focus-overlay-color($config-or-theme) {
  $config: mat-get-color-config($config-or-theme);
  $primary: map-get($config, primary);
  $accent: map-get($config, accent);
  $warn: map-get($config, warn);

  &.mat-primary .mat-button-focus-overlay {
    background-color: mat-color($primary);
  }

  &.mat-accent .mat-button-focus-overlay {
    background-color: mat-color($accent);
  }

  &.mat-warn .mat-button-focus-overlay {
    background-color: mat-color($warn);
  }

  &.mat-button-disabled .mat-button-focus-overlay {
    background-color: transparent;
  }
}

// Applies the background color for a ripple. If the value provided is not a Sass color,
// we assume that we've been given a CSS variable. Since we can't perform alpha-blending
// on a CSS variable, we instead add the opacity directly to the ripple element.
@mixin _mat-button-ripple-background($palette, $hue, $opacity) {
  $background-color: mat-color($palette, $hue, $opacity);
  background-color: $background-color;
  @if (type-of($background-color) != color) {
    opacity: $opacity;
  }
}

@mixin _mat-button-ripple-color($theme, $hue, $opacity: $_mat-button-ripple-opacity) {
  $primary: map-get($theme, primary);
  $accent: map-get($theme, accent);
  $warn: map-get($theme, warn);

  &.mat-primary .mat-ripple-element {
    @include _mat-button-ripple-background($primary, $hue, $opacity);
  }

  &.mat-accent .mat-ripple-element {
    @include _mat-button-ripple-background($accent, $hue, $opacity);
  }

  &.mat-warn .mat-ripple-element {
    @include _mat-button-ripple-background($warn, $hue, $opacity);
  }
}

// Applies a property to an mat-button element for each of the supported palettes.
@mixin _mat-button-theme-property($theme, $property, $hue) {
  $primary: map-get($theme, primary);
  $accent: map-get($theme, accent);
  $warn: map-get($theme, warn);
  $background: map-get($theme, background);
  $foreground: map-get($theme, foreground);

  &.mat-primary {
    #{$property}: mat-color($primary, $hue);
  }
  &.mat-accent {
    #{$property}: mat-color($accent, $hue);
  }
  &.mat-warn {
    #{$property}: mat-color($warn, $hue);
  }

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

@mixin mat-button-color($config-or-theme) {
  $config: mat-get-color-config($config-or-theme);
  $primary: map-get($config, primary);
  $accent: map-get($config, accent);
  $warn: map-get($config, warn);
  $background: map-get($config, background);
  $foreground: map-get($config, foreground);

  .mat-button, .mat-icon-button, .mat-stroked-button {
    // Buttons without a background color should inherit the font color. This is necessary to
    // ensure that the button is readable on custom background colors. It's wrong to always assume
    // that those buttons are always placed inside of containers with the default background
    // color of the theme (e.g. themed toolbars).
    color: inherit;
    background: transparent;

    @include _mat-button-theme-property($config, 'color', text);
    @include _mat-button-focus-overlay-color($config);

    // Setup the ripple color to be based on the text color. This ensures that the ripples
    // are matching with the current theme palette and are in contrast to the background color
    // (e.g in themed toolbars).
    .mat-ripple-element {
      opacity: $_mat-button-ripple-opacity;
      background-color: currentColor;
    }
  }

  .mat-button-focus-overlay {
    background: map-get($foreground, base);
  }

  // Note: this needs a bit extra specificity, because we're not guaranteed the inclusion
  // order of the theme styles and the button reset may end up resetting this as well.
  .mat-stroked-button:not(.mat-button-disabled) {
    border-color: mat-color($foreground, divider);
  }

  .mat-flat-button, .mat-raised-button, .mat-fab, .mat-mini-fab {
    // Default font and background color when not using any color palette.
    color: mat-color($foreground, text);
    background-color: mat-color($background, raised-button);

    @include _mat-button-theme-property($config, 'color', default-contrast);
    @include _mat-button-theme-property($config, 'background-color', default);
    @include _mat-button-ripple-color($config, default-contrast);
  }

  .mat-stroked-button, .mat-flat-button {
    @include mat-private-theme-overridable-elevation(0, $config);
  }

  .mat-raised-button {
    @include mat-private-theme-overridable-elevation(2, $config);

    &:not(.mat-button-disabled):active {
      @include mat-private-theme-overridable-elevation(8, $config);
    }

    &.mat-button-disabled {
      @include mat-private-theme-overridable-elevation(0, $config);
    }
  }

  .mat-fab, .mat-mini-fab {
    @include mat-private-theme-overridable-elevation(6, $config);

    &:not(.mat-button-disabled):active {
      @include mat-private-theme-overridable-elevation(12, $config);
    }

    &.mat-button-disabled {
      @include mat-private-theme-overridable-elevation(0, $config);
    }
  }
}

@mixin mat-button-typography($config-or-theme) {
  $config: mat-get-typography-config($config-or-theme);
  .mat-button, .mat-raised-button, .mat-icon-button, .mat-stroked-button,
  .mat-flat-button, .mat-fab, .mat-mini-fab {
    font: {
      family: mat-font-family($config, button);
      size: mat-font-size($config, button);
      weight: mat-font-weight($config, button);
    }
  }
}

@mixin _mat-button-density($config-or-theme) {}

@mixin mat-button-theme($theme-or-color-config) {
  $theme: mat-private-legacy-get-theme($theme-or-color-config);
  @include mat-private-check-duplicate-theme-styles($theme, 'mat-button') {
    $color: mat-get-color-config($theme);
    $density: mat-get-density-config($theme);
    $typography: mat-get-typography-config($theme);

    @if $color != null {
      @include mat-button-color($color);
    }
    @if $density != null {
      @include _mat-button-density($density);
    }
    @if $typography != null {
      @include mat-button-typography($typography);
    }
  }
}