Swiper - position of navigation controls

The default position of the navigation arrows or bullets will mean they’re likely to be invisible/unusable in many situations. Eg here’s an example of each - they’re visible, but only just:

I can use CSS to move the bullets down so they’re won’t be obscured, but I haven’t managed to move the arrows beyond the images/content, eg like this:

I can move the arrows further to the right or left, but then they become invisible. Is this possible?

I would be grateful for any suggestions.