Instead of making the width 0 to make it ‘disappear’ use the conditions to determine when they should be visible. So, if the group of buttons should be visible only when the page is less than 1200px, make it so in layout it is not visible on page load, then create a condition for when page width is greater than or equal to 1200px and set the property to change to ‘this element is visible’ and check to the box. Also, make sure to check the box in layout for ‘collapse when not visible’.
Then you also need to ensure your hamburger menu icon is contained by the group.