sass/elements/_button.scss
.#{$prefix}btn {
  color: $btn-color;
  display: inline-block;
  text-align: center;
  white-space: nowrap;
  font-weight: $btn-font-weight;
  vertical-align: middle;
  cursor: pointer;
  user-select: none;
  border-radius: $btn-radius;
  border: $btn-border-width solid $btn-bd-color;
  background-color: $white;
  line-height: 1;
  @include btn_size($btn-pd, $btn-font-size);
  @include btn_hover($btn-bg-color);
  @include btn_active($btn-bg-color);
  &.disabled,
  &[disabled]{
    color: $btn-disabled-color;
    border-color: $btn-disabled-bd-color;
    cursor: not-allowed;
    background-color: $white;
  }
  &:focus{
    outline:none;
  }
}

.#{$prefix}btn-link {
  color: $btn-link-color;
  border-color: transparent;
  background-color: transparent;

  &:hover {
    color: darken($btn-link-color, $btn-link-hover-darken);
    background-color: transparent;
  }
  &:active,
  &:focus {
    color: darken($btn-link-color, $btn-link-focus-darken);
    background-color: transparent;
  }
  &.disabled,
  &[disabled]{
    color: $btn-link-disabled-color;
    border-width: 0;
  }
}

@each $name,$color in $btn-situations {
  .#{$prefix}btn-#{$name} {
    @include btn_situation($color);
  }
}

.#{$prefix}btn-lg {
  @include btn_size($btn-lg-pd, $btn-lg-font-size);
}

.#{$prefix}btn-sm {
  @include btn_size($btn-sm-pd, $btn-sm-font-size);
}

.#{$prefix}btn-xs {
  @include btn_size($btn-xs-pd, $btn-xs-font-size);
}
