* {
    margin: 0;
    padding: 0;
}

body {
    background: black;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
}

ul {
    list-style: none;
    display: flex;
    background: rgb(54, 54, 54);
    border-radius: 10px;
    padding: 0;

}

.re {
    position: relative;
    padding: 20px 0;
    overflow:hidden ;
}

a {
    text-decoration: none;
    width: 100%;
    padding: 20px 30px;
    font-size: 20px;
    font-weight: 600;
    color: white;
    z-index: 1;
    position: relative;

}

.overly {
    position: absolute;
    top: 100%;
    right: 100%;
    width: 100%;
    height: 100%;
   background-image: linear-gradient(to right, rgba(0, 0, 255, .3) , blue);
    transition: .4s;
    border-radius: 10px;
}
.re:hover .overly {
    right: 0%;
   
    top: 0%;
   
}