Here are some helpful resources on changing screen resolution on common devices;
Please note that on iPads and other tablet devices we recommend using them in landscape mode rather than portrait.
Another common reason for the stacking is that the browser is zoomed.
On an Apple computer press ‘⌘’ + ‘-’ keys at the same time. Or from the menu bar choose View > Zoom Out.
On a Windows device press ‘Ctrl’ + ‘-’ keys at the same time.