.icon {
    display: inline-block;
    background: transparent none no-repeat scroll center center;
    position: relative;
}
.icon::before, .icon::after {
    content: "";
    position: absolute;
    top: 0px;
    left: 0px;
    width: 100%;
    height: 100%;
    background-color: transparent;
    background-repeat: no-repeat;
    background-position: center center;
}
.icon::after {
    opacity: 0;
}

a:hover .icon::before,
a:focus .icon::before,
.btn:hover .icon::before,
.btn:focus .icon::before,
.icon:hover::before,
.icon.active::before {
    opacity: 0;
}
a:hover .icon::after,
a:focus .icon::after,
.btn:hover .icon::after,
.btn:focus .icon::after,
.icon:hover::after,
.icon.active::after {
    opacity: 1;
}

.icon-prev {width: 48px; height: 50px;}
.icon-prev::before {background-image: url("../images/icons/icon-prev.svg");}
.icon-prev::after {background-image: url("../images/icons/icon-prev-dark.svg");}

.icon-next {width: 48px; height: 50px;}
.icon-next::before {background-image: url("../images/icons/icon-next.svg");}
.icon-next::after {background-image: url("../images/icons/icon-next-dark.svg");}

.icon-check {width: 30px; height: 30px;}
.icon-check::before {background-image: url("../images/icons/icon-check.svg");}
.icon-check::after {background-image: url("../images/icons/icon-check-dark.svg");}
    

.icon-up {width: 16px; height: 15px;}
.icon-up::before {background-image: url("../images/icons/icon-up.svg");}
.icon-up::after {background-image: url("../images/icons/icon-up-dark.svg");}