ant-design/style/mixins/button.less

// mixins for button
// ------------------------
.button-size(@padding; @font-size; @border-radius) {
  padding: @padding;
  font-size: @font-size;
  border-radius: @border-radius;
}

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

  &:hover {
    .button-color(fadeout(@color, 30%); fadeout(@background, 30%); fadeout(@border, 30%));
  }
  &:active,
  &.active {
    .button-color(fadeout(@color, 20%); fadeout(@background, 20%); fadeout(@border, 20%));
  }
  &:active,
  &.active {
    background-image: none;
  }

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

.button-color(@color; @background; @border) {
  color: @color;
  background-color: @background;
  border-color: @border;
}

.button-group-base(@btnClassName) {
  position: relative;
  display: inline-block;
  vertical-align: middle;
  > .@{btnClassName} {
    position: relative;
    float: left;
    &:hover,
    &:focus,
    &:active,
    &.active {
      z-index: 2;
    }
  }

  // size
  &-lg > .@{btnClassName} {
    .button-size(@btn-padding-lg; @btn-font-size-lg; @btn-border-radius-lg);
    > .@{iconfont-css-prefix} {
    font-size: @btn-font-size-lg + 2;
    }
  }

  &-sm > .@{btnClassName} {
    .button-size(@btn-padding-sm; @font-size-base; @btn-border-radius-sm);
    > .@{iconfont-css-prefix} {
      font-size: @font-size-base;
    }
  }
}

// Base styles of buttons
// --------------------------------------------------
.btn() {
  display: inline-block;
  margin-bottom: 0;
  font-weight: @btn-font-weight;
  text-align: center;
  vertical-align: middle;
  touch-action: manipulation;
  cursor: pointer;
  background-image: none;
  border: 1px solid transparent;
  // outline: none;
  white-space: nowrap;
  line-height: @line-height-base;
  .button-size(@btn-padding-base; @font-size-base; @btn-border-radius-base);
  .user-select(none);
  .transition(all .3s @ease-in-out);
  -webkit-transform: translate3d(0, 0, 0);

  > .@{iconfont-css-prefix} {
    font-size: @font-size-base + 2;
    line-height: 1;
    z-index: 2;
  }

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

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

  &:not([disabled]):active {
    outline: 0;
    .transition(none);
  }

  &.disabled,
  &[disabled]{
    cursor: @cursor-disabled;
  }

  &-lg {
    .button-size(@btn-padding-lg; @btn-font-size-lg; @btn-border-radius-lg);
    > .@{iconfont-css-prefix} {
      font-size: @btn-font-size-lg + 2;
    }
  }

  &-sm {
    .button-size(@btn-padding-sm; @font-size-base; @btn-border-radius-sm);
    > .@{iconfont-css-prefix} {
      font-size: @font-size-base;
    }
  }
}

// primary button style
.btn-primary() {
  .button-variant(@btn-primary-color; @btn-primary-bg; @btn-primary-border);

  &:hover,
  &:active,
  &.active {
    background-clip: padding-box;
    color: @btn-primary-color;
  }
}

// default button style
.btn-default() {
  .button-variant(@btn-default-color; @btn-default-bg; @btn-default-border);

  &:hover {
    .button-color(fadeout(@primary-color, 30%); @white; fadeout(@primary-color, 30%));
  }
  &:active,
  &.active {
    .button-color(fadeout(@primary-color, 20%); @white; fadeout(@primary-color, 20%));
  }
}

// ghost button style
.btn-ghost() {
  .button-variant(@btn-ghost-color, @btn-ghost-bg, @btn-ghost-border);

  &:hover {
    .button-color(fadeout(@primary-color, 30%); @white; fadeout(@primary-color, 30%));
  }
  &:active,
  &.active {
    .button-color(fadeout(@primary-color, 20%); @white; fadeout(@primary-color, 20%));
  }
}

// circle button: the content only contains icon
.btn-circle(@btnClassName: btn) {
  .square(@btn-circle-size);
  .button-size(0; @font-size-base + 2; 50%);

  > .@{iconfont-css-prefix} {
    top: -1px;
  }

  &.@{btnClassName}-lg {
    .square(@btn-circle-size-lg);
    .button-size(0; @btn-font-size-lg + 2; 50%);
  }

  &.@{btnClassName}-sm {
    .square(@btn-circle-size-sm);
    .button-size(0; @font-size-base; 50%);
  }
}

// circle button with stroke border
.btn-circle-outline() {
  position: relative;

  &:not([disabled]):before {
    position: absolute;
    top: 0;
    left: 0;
    display: inline-block;
    .opacity(0);
    width: 100%;
    height: 100%;
    border-radius: 50% 50%;
    content: " ";
    .scale(0, 0);
    .transition(all @duration-300 @ease-in-out);
    z-index: 0;
    background-color: @primary-color;
    background-clip: padding-box;
  }

  &:not([disabled]):hover, 
  &:not([disabled]):active,
  &:not([disabled]).active {
    > .@{iconfont-css-prefix} {
      color: @btn-primary-color;
    }
  }

  &:not([disabled]):hover:before, 
  &:not([disabled]):active:before,
  &:not([disabled]).active:before {
    .opacity(1);
    .scale(1, 1);
  }

  &:not([disabled]):active:before,
  &:not([disabled]).active:before {
    background-color: fadeout(@primary-color, 20%);
  }
}

// Horizontal button groups styl
// --------------------------------------------------
.btn-group(@btnClassName: btn) {
  .button-group-base(@btnClassName);

  .@{btnClassName} + .@{btnClassName},
  .@{btnClassName} + &,
  & + .@{btnClassName},
  & + & {
    margin-left: -1px;
  }

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

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

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

  > & {
    float: left;
  }

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

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

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