app/node_modules/ng-zorro-antd/button/style/mixin.less

// mixins for button
// ------------------------
.button-size(@height; @padding-horizontal; @font-size; @border-radius) {
  @padding-vertical: max(
    (round(((@height - @font-size * @line-height-base) / 2) * 10) / 10) - @border-width-base,
    0
  );
  height: @height;
  padding: @padding-vertical @padding-horizontal;
  font-size: @font-size;
  border-radius: @border-radius;
}

.button-color(@color; @background; @border) {
  color: @color;
  border-color: @border; // a inside Button which only work in Chrome
  & when not(@background = null) {
    background: @background;
  }
  // http://stackoverflow.com/a/17253457
  > a:only-child {
    color: currentcolor;

    &::after {
      position: absolute;
      top: 0;
      right: 0;
      bottom: 0;
      left: 0;
      background: transparent;
      content: '';
    }
  }
}

.button-disabled(@color: @btn-disable-color; @background: @btn-disable-bg; @border: @btn-disable-border) {
  &[disabled] {
    &,
    &:hover,
    &:focus,
    &:active {
      .button-color(@color; @background; @border);

      text-shadow: none;
      box-shadow: none;
    }
  }
}

.button-variant-primary(@color; @background; @backgroundHover: yellow; @backgroundActive: yellow) {
  .button-color(@color; @background; @background);

  text-shadow: @btn-text-shadow;
  box-shadow: @btn-primary-shadow;

  &:hover,
  &:focus {
    & when (@theme = dark) {
      .button-color(
        @color; colorPalette('@{background}', 7); colorPalette('@{background}', 7)
      );
    }
    & when (not (@theme = dark) and not (@theme = variable)) {
      .button-color(
        @color; colorPalette('@{background}', 5); colorPalette('@{background}', 5)
      );
    }
    & when (@theme = variable) {
      .button-color(@color; @backgroundHover; @backgroundHover);
    }
  }

  &:active {
    & when (@theme = dark) {
      .button-color(
        @color; colorPalette('@{background}', 5); colorPalette('@{background}', 5)
      );
    }
    & when (not (@theme = dark) and not (@theme = variable)) {
      .button-color(
        @color; colorPalette('@{background}', 7); colorPalette('@{background}', 7)
      );
    }
    & when (@theme = variable) {
      .button-color(@color; @backgroundActive; @backgroundActive);
    }
  }

  .button-disabled();
}

.button-variant-other(@color; @background; @border) {
  .button-color(@color; @background; @border);

  &:hover,
  &:focus {
    & when (@theme = dark) {
      .button-color(@primary-5; @background; @primary-5);
    }
    & when (not (@theme = dark) and not (@theme = variable)) {
      .button-color(
        colorPalette('@{btn-primary-bg}', 5); @background;
          colorPalette('@{btn-primary-bg}', 5)
      );
    }
    & when (@theme = variable) {
      .button-color(@primary-color-hover; @background; @primary-color-hover);
    }
  }

  &:active {
    & when (@theme = dark) {
      .button-color(@primary-7; @background; @primary-7);
    }
    & when (not (@theme = dark) and not (@theme = variable)) {
      .button-color(
        colorPalette('@{btn-primary-bg}', 7); @background;
          colorPalette('@{btn-primary-bg}', 7)
      );
    }
    & when (@theme = variable) {
      .button-color(@primary-color-active; @background; @primary-color-active);
    }
  }
  .button-disabled();
}

.button-variant-ghost(@color; @border; @borderHover: yellow; @borderActive: yellow) {
  .button-color(@color; null; @border);
  text-shadow: none;

  &:hover,
  &:focus {
    & when (@border = transparent) {
      & when (@theme = dark) {
        .button-color(colorPalette('@{color}', 7); null; transparent);
      }
      & when (not (@theme = dark) and not (@theme = variable)) {
        .button-color(colorPalette('@{color}', 5); null; transparent);
      }
      & when (@theme = variable) {
        .button-color(@borderActive; transparent; transparent);
      }
    }
    & when not (@border = transparent) {
      & when (@theme = dark) {
        .button-color(
          colorPalette('@{color}', 7); null; colorPalette('@{color}', 7)
        );
      }
      & when (not (@theme = dark) and not (@theme = variable)) {
        .button-color(
          colorPalette('@{color}', 5); null; colorPalette('@{color}', 5)
        );
      }
      & when (@theme = variable) {
        .button-color(@borderHover; transparent; @borderHover);
      }
    }
  }

  &:active {
    & when (@border = transparent) {
      & when (@theme = dark) {
        .button-color(colorPalette('@{color}', 5); null; transparent);
      }
      & when (not (@theme = dark) and not (@theme = variable)) {
        .button-color(colorPalette('@{color}', 7); null; transparent);
      }
      & when (@theme = variable) {
        .button-color(@borderActive; transparent; transparent);
      }
    }
    & when not (@border = transparent) {
      & when (@theme = dark) {
        .button-color(
          colorPalette('@{color}', 5); null; colorPalette('@{color}', 5)
        );
      }
      & when (not (@theme = dark) and not (@theme = variable)) {
        .button-color(
          colorPalette('@{color}', 7); null; colorPalette('@{color}', 7)
        );
      }
      & when (@theme = variable) {
        .button-color(@borderActive; transparent; @borderActive);
      }
    }
  }
  .button-disabled();
}

.button-group-base(@btnClassName) {
  position: relative;
  display: inline-flex;
  > .@{btnClassName},
  > span > .@{btnClassName} {
    position: relative;

    &:hover,
    &:focus,
    &:active {
      z-index: 2;
    }

    &[disabled] {
      z-index: 0;
    }
  }
  .@{btnClassName}-icon-only {
    font-size: @font-size-base;
  }
}
// Base styles of buttons
// --------------------------------------------------
.btn() {
  position: relative;
  display: inline-block;
  font-weight: @btn-font-weight;
  white-space: nowrap;
  text-align: center;
  background-image: none;
  border: @btn-border-width @btn-border-style transparent;
  box-shadow: @btn-shadow;
  cursor: pointer;
  transition: all 0.3s @ease-in-out;
  user-select: none;
  touch-action: manipulation;
  .button-size(
    @btn-height-base; @btn-padding-horizontal-base; @font-size-base; @btn-border-radius-base
  );
  > .@{iconfont-css-prefix} {
    line-height: 1;
  }

  &,
  &:active,
  &:focus {
    outline: 0;
  }

  &:not([disabled]):hover {
    text-decoration: none;
  }

  &:not([disabled]):active {
    outline: 0;
    box-shadow: none;
  }

  &[disabled] {
    cursor: not-allowed;

    > * {
      pointer-events: none;
    }
  }

  &-lg {
    .button-size(
      @btn-height-lg; @btn-padding-horizontal-lg; @btn-font-size-lg; @btn-border-radius-base
    );
  }

  &-sm {
    .button-size(
      @btn-height-sm; @btn-padding-horizontal-sm; @btn-font-size-sm; @btn-border-radius-sm
    );
  }
}
// primary button style
.btn-primary() {
  .button-variant-primary(@btn-primary-color; @btn-primary-bg; @primary-color-hover; @primary-color-active);
}
// default button style
.btn-default() {
  .button-variant-other(@btn-default-color; @btn-default-bg; @btn-default-border; );

  &:hover,
  &:focus,
  &:active {
    text-decoration: none;
    background: @btn-default-bg;
  }
}
// ghost button style
.btn-ghost() {
  .button-variant-other(@btn-ghost-color, @btn-ghost-bg, @btn-ghost-border);
}
// dashed button style
.btn-dashed() {
  .button-variant-other(@btn-default-color, @btn-default-bg, @btn-default-border);
  border-style: dashed;
}
// danger button style
.btn-danger() {
  .button-variant-primary(@btn-danger-color, @btn-danger-bg, @error-color-hover, @error-color-active);
}
// danger default button style
.btn-danger-default() {
  .button-color(@error-color, @btn-default-bg, @error-color);

  &:hover,
  &:focus {
    & when (@theme = dark) {
      .button-color(
        colorPalette('@{error-color}', 7); @btn-default-bg; colorPalette('@{error-color}', 7)
      );
    }
    & when (not (@theme = dark) and not (@theme = variable)) {
      .button-color(
        colorPalette('@{error-color}', 5); @btn-default-bg; colorPalette('@{error-color}', 5)
      );
    }
    & when (@theme = variable) {
      .button-color(@error-color-hover, @btn-default-bg, @error-color-hover);
    }
  }

  &:active {
    & when (@theme = dark) {
      .button-color(
        colorPalette('@{error-color}', 5); @btn-default-bg; colorPalette('@{error-color}', 5)
      );
    }
    & when (not (@theme = dark) and not (@theme = variable)) {
      .button-color(
        colorPalette('@{error-color}', 7); @btn-default-bg; colorPalette('@{error-color}', 7)
      );
    }
    & when (@theme = variable) {
      .button-color(@error-color-active, @btn-default-bg, @error-color-active);
    }
  }
  .button-disabled();
}
// danger link button style
.btn-danger-link() {
  .button-variant-other(@error-color, transparent, transparent);
  box-shadow: none;

  &:hover,
  &:focus {
    & when (@theme = dark) {
      .button-color(colorPalette('@{error-color}', 7); transparent; transparent);
    }
    & when (not (@theme = dark) and not (@theme = variable)) {
      .button-color(colorPalette('@{error-color}', 5); transparent; transparent);
    }
    & when (@theme = variable) {
      .button-color(@error-color-hover; transparent; transparent);
    }
  }

  &:active {
    & when (@theme = dark) {
      .button-color(colorPalette('@{error-color}', 5); transparent; transparent);
    }
    & when (not (@theme = dark) and not (@theme = variable)) {
      .button-color(colorPalette('@{error-color}', 7); transparent; transparent);
    }
    & when (@theme = variable) {
      .button-color(@error-color-active; transparent; transparent);
    }
  }
  .button-disabled(@disabled-color; transparent; transparent);
}
// link button style
.btn-link() {
  .button-variant-other(@link-color, transparent, transparent);
  box-shadow: none;

  &:hover {
    background: @btn-link-hover-bg;
  }

  &:hover,
  &:focus,
  &:active {
    border-color: transparent;
  }
  .button-disabled(@disabled-color; transparent; transparent);
}
// link button disabled style
.btn-href-disabled() {
  cursor: not-allowed;

  > * {
    pointer-events: none;
  }

  &,
  &:hover,
  &:focus,
  &:active {
    .button-color(@btn-disable-color,transparent, transparent);

    text-shadow: none;
    box-shadow: none;
  }
}
// text button style
.btn-text() {
  .button-variant-other(@text-color, transparent, transparent);
  box-shadow: none;

  &:hover,
  &:focus {
    color: @text-color;
    background: @btn-text-hover-bg;
    border-color: transparent;
  }

  &:active {
    color: @text-color;
    background: fadein(@btn-text-hover-bg, 1%);
    border-color: transparent;
  }

  .button-disabled(@disabled-color; transparent; transparent);
}
.btn-danger-text() {
  .button-variant-other(@error-color, transparent, transparent);
  box-shadow: none;

  &:hover,
  &:focus {
    & when (@theme = dark) {
      .button-color(colorPalette('@{error-color}', 7); @btn-text-hover-bg; transparent);
    }
    & when (not (@theme = dark) and not (@theme = variable)) {
      .button-color(colorPalette('@{error-color}', 5); @btn-text-hover-bg; transparent);
    }
    & when (@theme = variable) {
      .button-color(@error-color-hover; @btn-text-hover-bg; transparent);
    }
  }

  &:active {
    & when (@theme = dark) {
      .button-color(colorPalette('@{error-color}', 5); fadein(@btn-text-hover-bg, 1%); transparent);
    }
    & when (not (@theme = dark) and not (@theme = variable)) {
      .button-color(colorPalette('@{error-color}', 7); fadein(@btn-text-hover-bg, 1%); transparent);
    }
    & when (@theme = variable) {
      .button-color(@error-color-active; fadein(@btn-text-hover-bg, 1%); transparent);
    }
  }
  .button-disabled(@disabled-color; transparent; transparent);
}
// round button
.btn-round(@btnClassName: btn) {
  .button-size(@btn-circle-size; (@btn-circle-size / 2); @font-size-base; @btn-circle-size);
  &.@{btnClassName}-lg {
    .button-size(
      @btn-circle-size-lg; (@btn-circle-size-lg / 2); @btn-font-size-lg; @btn-circle-size-lg
    );
  }
  &.@{btnClassName}-sm {
    .button-size(
      @btn-circle-size-sm; (@btn-circle-size-sm / 2); @font-size-base; @btn-circle-size-sm
    );
  }
}
// square button: the content only contains icon
.btn-square(@btnClassName: btn) {
  .square(@btn-square-size);
  .button-size(@btn-square-size; 0; @btn-square-only-icon-size; @btn-border-radius-base);

  & > * {
    font-size: @btn-square-only-icon-size;
  }
  &.@{btnClassName}-lg {
    .square(@btn-square-size-lg);
    .button-size(@btn-square-size-lg; 0; @btn-square-only-icon-size-lg; @btn-border-radius-base);

    & > * {
      font-size: @btn-square-only-icon-size-lg;
    }
  }
  &.@{btnClassName}-sm {
    .square(@btn-square-size-sm);
    .button-size(@btn-square-size-sm; 0; @btn-square-only-icon-size-sm; @btn-border-radius-base);

    & > * {
      font-size: @btn-square-only-icon-size-sm;
    }
  }
}
// circle button: the content only contains icon
.btn-circle(@btnClassName: btn) {
  min-width: @btn-height-base;
  padding-right: 0;
  padding-left: 0;
  text-align: center;
  border-radius: 50%;
  &.@{btnClassName}-lg {
    min-width: @btn-height-lg;
    border-radius: 50%;
  }
  &.@{btnClassName}-sm {
    min-width: @btn-height-sm;
    border-radius: 50%;
  }
}
// Horizontal button groups style
// --------------------------------------------------
.btn-group(@btnClassName: btn) {
  .button-group-base(@btnClassName);
  .@{btnClassName} + .@{btnClassName},
  .@{btnClassName} + &,
  span + .@{btnClassName},
  .@{btnClassName} + span,
  > span + span,
  & + .@{btnClassName},
  & + & {
    margin-left: -1px;
  }
  .@{btnClassName}-primary + .@{btnClassName}:not(.@{btnClassName}-primary):not([disabled]) {
    border-left-color: transparent;
  }
  .@{btnClassName} {
    border-radius: 0;
  }
  > .@{btnClassName}:first-child,
  > span:first-child > .@{btnClassName} {
    margin-left: 0;
  }
  > .@{btnClassName}:only-child {
    border-radius: @btn-border-radius-base;
  }
  > span:only-child > .@{btnClassName} {
    border-radius: @btn-border-radius-base;
  }
  > .@{btnClassName}:first-child:not(:last-child),
  > span:first-child:not(:last-child) > .@{btnClassName} {
    border-top-left-radius: @btn-border-radius-base;
    border-bottom-left-radius: @btn-border-radius-base;
  }
  > .@{btnClassName}:last-child:not(:first-child),
  > span:last-child:not(:first-child) > .@{btnClassName} {
    border-top-right-radius: @btn-border-radius-base;
    border-bottom-right-radius: @btn-border-radius-base;
  }

  &-sm {
    > .@{btnClassName}:only-child {
      border-radius: @btn-border-radius-sm;
    }
    > span:only-child > .@{btnClassName} {
      border-radius: @btn-border-radius-sm;
    }
    > .@{btnClassName}:first-child:not(:last-child),
    > span:first-child:not(:last-child) > .@{btnClassName} {
      border-top-left-radius: @btn-border-radius-sm;
      border-bottom-left-radius: @btn-border-radius-sm;
    }
    > .@{btnClassName}:last-child:not(:first-child),
    > span:last-child:not(:first-child) > .@{btnClassName} {
      border-top-right-radius: @btn-border-radius-sm;
      border-bottom-right-radius: @btn-border-radius-sm;
    }
  }

  & > & {
    float: left;
  }
  & > &:not(:first-child):not(:last-child) > .@{btnClassName} {
    border-radius: 0;
  }

  & > &:first-child:not(:last-child) {
    > .@{btnClassName}:last-child {
      padding-right: 8px;
      border-top-right-radius: 0;
      border-bottom-right-radius: 0;
    }
  }
  & > &:last-child:not(:first-child) > .@{btnClassName}:first-child {
    padding-left: 8px;
    border-top-left-radius: 0;
    border-bottom-left-radius: 0;
  }
}