Practice/_src/admin/scss/boot/_mixins.scss

// Clear FIX
@mixin clear-fix() {
  display:block;
  clear:both;
  content:"";
}

@mixin clear-fix-after() {
  &:after {
    display:block;
    clear:both;
    content:"";
  }
}

// Global Transition
@mixin transition($second:.3s, $target:all, $animation:$default-animation)
{
  -webkit-transition: $target $second $animation;
  -moz-transition: $target $second $animation;
  -ms-transition: $target $second $animation;
  -o-transition: $target $second $animation;
  transition: $target $second $animation;
}

// Display flex & Prefix
@mixin display-flex()
{
  -webkit-display:flex;
  display:-ms-flex;
  display:flex;
}

@mixin background-gradient($start, $end )
{
  background-color: $start;
  background-image: -webkit-linear-gradient(top, $start, $end);
  background-image: linear-gradient(to bottom,$start, $end);
}

@mixin button-size($padding-y, $padding-x, $font-size, $line-height, $border-radius) {
  padding: $padding-y $padding-x;
  font-size: $font-size;
  line-height: $line-height;
  border-radius: $border-radius;
}

@mixin button-variant($background, $border, $hover-background: darken($background, 7.5%), $hover-border: darken($border, 10%), $active-background: darken($background, 10%), $active-border: darken($border, 12.5%)) {
  color: color-yiq($background);
  background-color:$background;
  border-color: $border;

  &:hover {
    color: color-yiq($hover-background);
    background-color :$hover-background;
    border-color: $hover-border;
  }

  &:focus,
  &.focus {

  }

  // Disabled comes first so active can properly restyle
  &.disabled,
  &:disabled {
    color: color-yiq($background);
    background-color: $background;
    border-color: $border;
  }

  &:not(:disabled):not(.disabled):active,
  &:not(:disabled):not(.disabled).active,
  .show > &.dropdown-toggle {
    color: color-yiq($active-background);
    background-color: $active-background;
    border-color: $active-border;

    &:focus {

    }
  }
}