Bootstrap 3 responsive mixins

// 1200px+
@mixin only-desktop-hd() {
  @media (min-width: $screen-lg-min) { @content }
}

// 992px - 1200px
@mixin only-desktop() {
  @media (min-width: $screen-md-min) and (max-width: $screen-md-max) { @content }
}
@mixin at-least-desktop() {
  @media (min-width: $screen-md-min) { @content }
}
@mixin at-most-desktop() {
  @media (max-width: $screen-md-max) { @content }
}

// 768px - 991px
@mixin only-tablet() {
  @media (min-width: $screen-sm-min) and (max-width: $screen-sm-max) { @content }
}
@mixin at-least-tablet() {
  @media (min-width: $screen-sm-min) { @content }
}
@mixin at-most-tablet() {
  @media (max-width: $screen-sm-max) { @content }
}

// 0px - 767px
@mixin only-mobile() {
  @media (max-width: $screen-xs-max) { @content }
}