css grid, sass, gulp , js

how do you add a dark overlay to the body when the hamburger menu is clicked?

i created div element with "hide" class . i used z-position with higher number so that can be displayed above the header element. the property and the value of the hide class is "display : none" that is the default value. and the i used java script to add and other class called show which can has "display: block". and when the button is clicked , javascript add "show" class and " remove " hide class. for more information please take a look at this link https://www.w3schools.com/howto/howto_js_toggle_hide_show.asp https://stackoverflow.com/questions/21070101/show-hide-div-using-javascript

thank you