HTML `dialog` element: scroll content independently of background

Question

I am trying to use the dialog element.

When the dialog/modal is closed, the body should be scrollable.

When the dialog/modal is open, if it has larg

Answer 1

Update

I created another example where your main content is not scrolled with your modal if it is larger than your main content. You can set position to fixed on your container to achieve this.

(function() {
  var openBtn = document.getElementById('open-dialog');
  var myDialog = document.getElementById('my-dialog');

  openBtn.addEventListener('click', function() {
    if (typeof myDialog.showModal === "function") {
      myDialog.showModal();
    } else {
      alert("Dialog API not supported by browser");
    }
  });

})();

#container {
  height: 100vh;
  width: 100vw;
  position: fixed;
  top: 0;
  left: 0;
  background: #ccc;
}

#my-dialog {
  margin-top: 1rem;
  margin-bottom: 3rem;
  top: 3rem;
  width: 50%;
  overflow-y: auto;
}

#my-dialog__content {
  display: flex;
  flex-direction: column;
  height: 200vh;
}

menu {
  width: 100%;
  padding: 0;
  margin: 0 auto;
}

#cancel-button {
  width: 100%
}

  

    

      

        
          Cancel
        
      
    
  

  
    Open Dialog
  

Original answer

You can set a max-height on your dialog and style the contents of your dialog accordingly. See example below.

(function() {
  var openBtn = document.getElementById('open-dialog');
  var myDialog = document.getElementById('my-dialog');

  openBtn.addEventListener('click', function() {
    if (typeof myDialog.showModal === "function") {
      myDialog.showModal();
    } else {
      alert("Dialog API not supported by browser");
    }
  });

})();

#my-dialog {
  width: 50%;
  max-height: 50vh;
  overflow-y: auto;
}

#my-dialog__content {
  display: flex;
  flex-direction: column;
  height: 150vh;
}

menu {
  width: 100%;
  padding: 0;
  margin: 0 auto;
}

#cancel-button {
  width: 100%
}

  

    

      

        
          Cancel
        
      
    
  

  
    Open Dialog