CODE EXAMPLE FOR JAVASCRIPT

Navigation sidebar animated

#sidebarCollapse span:first-of-type {
    /* rotate first one */
    transform: rotate(45deg) translate(2px, 2px);
}
#sidebarCollapse span:nth-of-type(2) {
    /* second one is not visible */
    opacity: 0;
}
#sidebarCollapse span:last-of-type {
    /* rotate third one */
    transform: rotate(-45deg) translate(1px, -1px);
}