framework/less/common/mixins/light-contents.less

// This is a mixin which styles components (buttons, inputs, etc.) for use on
// dark backgrounds.
.light-contents(@color: #fff; @control-bg: fade(#000, 10%); @control-color: #fff; @name: 'light-content') {
  &, a {
    color: var(~"--@{name}-color", @color);
  }
  .Button--link, .Search-input {
    color: var(~"--@{name}-control-color", @control-color);
  }
  .FormControl {
    background: var(~"--@{name}-control-bg", @control-bg);
    border: 0;
    color: var(~"--@{name}-control-color", @control-color);
    .placeholder(var(~"--@{name}-control-color", @control-color));

    &:focus {
      color: @color;
      background: var(~"--@{name}-control-bg-shaded", fadein(darken(@control-bg, 5%), 10%));
    }
  }
  .Button, .Button:hover {
    color: var(~"--@{name}-control-color", @control-color);
    background: var(~"--@{name}-control-bg", @control-bg);
  }
  .Button--flat {
    background: transparent;
  }
  .Button:active,
  .Button.active,
  .Button:focus,
  .Button.focus,
  .open > .Dropdown-toggle.Button {
    background: var(~"--@{name}-control-bg-fadedin", fadein(@control-bg, 5%));
    color: var(~"--@{name}-control-color", @control-color);
  }
}

.light-contents-vars(@color: #fff; @control-bg: fade(#000, 10%); @control-color: #fff; @name: 'light-content') {
  @componentName: ~"@{name}";

  --@{componentName}-color: @color;
  --@{componentName}-control-color: @control-color;
  --@{componentName}-control-bg: @control-bg;
  --@{componentName}-control-bg-shaded: fadein(darken(@control-bg, 5%), 10%);
  --@{componentName}-control-bg-fadedin: fadein(@control-bg, 5%);
}