Too wide for mobile site

Website: http://reasonstocomehome.com

The share buttons element fits correctly when viewed on a laptop or desktop screen, but is wider than the body content when viewed on an iPhone or other mobile device.

I’ve tried changing the width parameters in the Media Queries (@media only…) and nothing I’ve done has had any effect.

What can I do to make it the same width as the body on the mobile site?

https://wordpress.org/plugins/simple-share-buttons-adder/