// Compatibility for browsers.

// rotate for ie8 and blow
.ie-rotate(@rotation) {
  -ms-filter: "progid:DXImageTransform.Microsoft.BasicImage(rotation=@{rotation})";
}

// rotate for ie8 and blow
// degrees unit
.ie-rotate-via-degrees(@degrees) {
  /* IE6-IE8 */
  @radians: ~`parseInt("@{degrees}") * Math.PI * 2 / 360`;
  @costheta: ~`Math.cos("@{radians}")`;
  @sintheta: ~`Math.sin("@{radians}")`;
  @negsintheta: ~`"@{sintheta}" * -1`;
  -ms-filter: "progid:DXImageTransform.Microsoft.Matrix(sizingMethod='auto expand', M11=@{costheta}, M12=@{negsintheta}, M21=@{sintheta}, M22=@{costheta})";
  zoom: 1;

  :root & {
    filter: none;
  }
}

// support rotate for all browsers
.cross-rotate(@degrees) {
  .rotate(@degrees);
  .ie-rotate-via-degrees(@degrees);
}

// Placeholder text
.placeholder(@color: @input-placeholder-color) {
  // Firefox
  &::-moz-placeholder {
    color: @color;
    opacity: 1; // Override Firefox's unusual default opacity; see https://github.com/twbs/bootstrap/pull/11526
  }
  // Internet Explorer 10+
  &:-ms-input-placeholder {
    color: @color;
  }
  // Safari and Chrome
  &::-webkit-input-placeholder {
    color: @color;
  }
}