.nav-icons{
    width: 50px;
    height: 50px;
    margin: 0 10px;
    display: flex;
    justify-content: center;
    align-items: center;
    position: relative;
    border-radius: 50%;
    overflow: hidden;
}
.nav-icons a{
    color: white;
}
.nav-icons::before{
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(to left,#1899d5,#35adc2);
    z-index: -1;
    border-radius: 50%;
    transform: translate(100%,100%);
    transition: all .4s;
}
.nav-icons:hover::before{
    transform: translate(0);
    animation: anim .4s linear;
}
@keyframes anim{
    0%,100%{
        width: 100%;
        height: 100%;
    }
    50%{
        width: 50%;
        height: 50%;
    }
}

.nav-icons img
{
    width:40px;
    height:40px;
}