@mixin biseau($size) {
    position: relative;
    z-index: 1;
    overflow: visible;

    &:before {
        content: " ";
        position: absolute;
        top: 0;
        left: -$size/2;
        right: -$size/2;
        bottom: 0;
        z-index: -1;
        transform: skewX(-15deg);
        transition: background-color 0.3s;
    }
}

@mixin shape-style($size) {
    @include borders();
    @include border-radius($btn-radius);
    @include biseau($size);

    background-color:transparent;
}

@mixin colorize-shape($background-color) {
    background-color: $background-color;

    &:before {
        background-color: $background-color;
    }
}