I am using Joomlaplate Adventures template and have a menu bar underneath the full width header picture. I set the width of the six menu items so that they exactly fill the full width of the header picture, which is also the width of the page. The template sets the page width at 1100px. All is fine in my browser until I zoom in. At 110% it is still ok and at 150% it switches to the mobile view, but at 125% the last menu item flips onto the line below. Not only that but it is then not visible as it is on a white background. This is also the case when viewing it on an ipad in landscape, although not on my android tablet. On the ipad zooming in and out does not change anything, the last menu item stays on the line below. The only way I can stop this happening is to reduce the padding between the menu items so that they do not fill the full width in the first place. This to me, though, is a poor solution as it spoils the look for over 90% of the viewing senarios.
Can you help please, bearing in mind that I am quite happy to customise the css code if necessary.