.notification-bubble(@color: white, @width: 1.5em, @right: 0, @top: @width / 2, @background-color: @brand-danger) {
    position: relative;

    &[data-bubble]:after {
        display: block;
        width: @width;
        height: @width;

        position: absolute;
        top: @top;
        right: @right;

        font-size: @font-size-tiny;
        line-height: @width;
        text-align: center;
        border-radius: 50%;
        background-color: @background-color;
        color: @color;
        content: attr(data-bubble);
    }
}