当侧边菜单div接近0px时，导航链接不会隐藏

Question

I am trying to create a css side menu but when I close the menu, setting div container width to 0, the links are still visible.

Here is the jsfiddle - https://jsfiddle.net/atLvp6k7/

Interestingly, when I set the menu to the right of the screen I do not have the same problem. Do I need to add margin properties to the a items?

<div id="side-menu" class="side-nav">  
   <img id="close-side" src="https://floraisabelle.com/assets/images/hamburger-menu.png?v=aa3f825eb7" alt="">
    <a class="" href="#">Hi</a>
    <a class="" href="#">Hi</a>
    <a class="" href="#">Hi</a>
    <a class="" href="#">Hi</a>
</div>

var isOpen = false;
document.getElementById('close-side').addEventListener("click", function(){
    if (isOpen) {
        document.getElementById("side-menu").style.width = "0px";
        document.getElementById("close-side").style.marginLeft = "0px";
        isOpen = false;
    } else {
        document.getElementById("side-menu").style.width = "250px";
        document.getElementById("close-side").style.marginLeft = "181px";
        isOpen = true;
    } 
})

.side-nav {
  transition: .5s;
  height: 100%;
  width:0;
  background-color: rgba(120, 120, 120, 0.1);
  position: fixed;
  top: 0;
  left: 0;
  z-index: 1; 
}

#close-side {
  margin-left: 0;
  margin-top: 5px;
  transition: linear .5s;
  position: fixed; 
}

Answer 1

css

.side-hidden a {
   display: none;
}

HTML

<div id="side-menu" class="side-nav side-hidden">  

SCRIPT

 var isOpen = false;
 document.getElementById('close-side').addEventListener("click", function(){
 if (isOpen) {
        document.getElementById("side-menu").classList.add('side-hidden');
        document.getElementById("side-menu").style.width = "0px";
        document.getElementById("close-side").style.marginLeft = "0px";
        isOpen = false;
    } else {
        document.getElementById("side-menu").classList.remove('side-hidden');
        document.getElementById("side-menu").style.width = "250px";
        document.getElementById("close-side").style.marginLeft = "181px";
        isOpen = true;
    } 
})

I have updated your fiddle also https://jsfiddle.net/atLvp6k7/1/

there is no need for isOpen Variable

if(document.getElementById("side-menu").classList.contains('side-hidden')){
  alert('isClosed');
}else{
   alert('isOpen');
}

Answer 2

you can change the margin of the sidebar instead of width....

here is how to do it -

document.getElementById('close-side').addEventListener("click", function(){
    if (isOpen) {
        document.getElementById("close-side").style.marginLeft = "-100px";
        isOpen = false;
    } else {
        document.getElementById("close-side").style.marginLeft = "0px";
        isOpen = true;
    } 
})

and place the button (close-side) outside the sidebar div

<img id="close-side" src="https://floraisabelle.com/assets/images/hamburger-menu.png?v=aa3f825eb7" alt="">

<div id="side-menu" class="side-nav">  
    <a class="" href="#">Hi</a>
    <a class="" href="#">Hi</a>
    <a class="" href="#">Hi</a>
    <a class="" href="#">Hi</a>
</div>

now apply following css for the transition effect -

.side-nav
{
   transition: all 0.5s ease;
}