.menu-slide {
    max-height: 0;
    overflow: hidden;
    transition: max-height 350ms ease, padding 250ms ease;
}

/* hamburger padrão */
.hamburger span {
    width: 28px;
    height: 3px;
    background: white;
    border-radius: 4px;
    transition: transform 300ms ease, opacity 300ms ease;
}

/* animação para X */
.hamburger.open span:nth-child(1) {
    transform: translateY(8px) rotate(45deg);
}
.hamburger.open span:nth-child(2) {
    opacity: 0;
}
.hamburger.open span:nth-child(3) {
    transform: translateY(-8px) rotate(-45deg);
}