@mixin hover() {
    &:hover {
        @content;
    }
}

@mixin hover-focus() {
    &:hover,
    &:focus {
        @content;
    }
}

@mixin plain-hover-focus() {
    &,
    &:hover,
    &:focus {
        @content;
    }
}

@mixin hover-focus-active() {
    &:hover,
    &:focus,
    &:active {
        @content;
    }
}