Website is displaying a white space on right side of screen in iPhone

Solution 1:

The trouble is in your <h3 class="menu-toggle">Menu</h3> (why h3, btw?), which appears to be wider than a viewport because of having width: 100% + some padding.

Try setting a box-sizing: border-box; to that element.

Solution 2:

This worked a treat Tigran.

I just added a global class at the top of my stylesheet:

div {
  box-sizing: border-box;
  }

Cheers!