.footer-nav {
    width: 100vw;
    position: fixed;
    z-index: 999999;
    bottom: 0;
    left: 0%;
    max-height: 4rem;
    box-shadow: 0px -2px 4px rgba(185, 185, 185, 0.3);
    background-color: #fff;
    overflow: hidden;
}
.footer-nav .nav-item {
    line-height: 1.75;
}
.footer-nav .nav-item a {
    padding: 1rem 0;
    position: relative;
    overflow: hidden;
    z-index: 2;
}
.footer-nav .nav-item svg {
    stroke: var(--primary-color);
    width: 1.6rem;
    height: 1.6rem;
    margin-bottom: .4rem;
}
.footer-nav .nav-item.active-item span {
    font-weight: 700;
    color: var(--primary-color);
}
.footer-nav .nav-item span {
    font-size: .75rem;
    color: #171717;
    font-weight: 500;
    letter-spacing: 0.02em;
    line-height: 1;
}
.footer-nav .nav-item .footer-menu-item::after {
    position: absolute;
    content: '';
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 50px;
    height: 50px;
    background-color: rgba(0,0,0,0);
    border-radius: 100%;
    z-index: 1;
}
.footer-nav .nav-item:not(.active-item) .footer-menu-item:active::after,
.footer-nav .nav-item:not(.active-item) .footer-menu-item:focus::after {
    animation: growWave .8s ease forwards;
}
@keyframes growWave {
    0% {
        background-color: rgba(0,0,0,0);
    }
    40% {
        width: 150%;
        height: 150%;
        background-color: rgba(0,0,0,.08);
    }
    70% {
        width: 150%;
        height: 150%;
        background-color: rgba(0,0,0,.08);
    }
    100% {
        width: 150%;
        height: 150%;
    }
}