body {
    --megamenu-main-color : var(--white, #fff);
    --megamenu-sub-color : var(--black, #000);
}
body.active-megamenu {
    height: 100vh;
    overflow: hidden!important;
}
.megamenu {
    position: fixed;
    z-index: 98;
    width: 100%;
    height: 100vh ;
    transform: translateX(-100%);
    background-color: var(--megamenu-main-color);
    opacity: 0;
    transition: all .3s ease-in-out;
}
.megamenu-wrapper {
    width: 100%;
}
.megamenu.active {
    opacity: 1;
    transform: translateX(0);
}
.megamenu * {
    transition: inherit;
}