menu.css

body
{
    margin: 0;
    padding: 0;
    display: flex;
    justify-content: center;
    align-items: top;
    height: 80vh;
    background: linear-gradient(180deg,#036eb7,#64eaff);
}
ul
{
    margin: 0;
    padding: 0;
    display: flex;
}
ul li
{
    list-style: none;
    margin: 0 30px;
    transition: 0.5s;
}
ul li a
{
    display: block;
    position: relative;
    text-decoration: none;
    padding: 5px;
    font-size: 18px;
    font-family: sans-serif;
    color: #fff;
    text-transform: uppercase;
    transition: 0.5s;
}
ul:hover li a
{
    transform: scale(1.5);
    opacity: .2;
    filter: blur(5px);
}
ul li a:hover
{
    transform: scale(2);
    opacity: 1;
    filter: blur(0);
}
ul li a:before
{
    content: '';
    position: absolute;
    top:0;
    left: 0;
    width:100%;
    height: 100%;
    background: #ff497c;
    transition: transfrom 0.2s;
    transform-origin: right;
    transform: scale(0);
    z-index: -1;
}
ul li a:hover:before
{
    transition: transfrom 0.2s;
    transform-origin: left;
    transform: scale(1);
}