Custom Coding to resize gallery and thumbnails

Site URL: http://www.craig-gibson.com

Hi, I'm looking for someone who is familiar with code to help me with some customising of my website. I'm trying to resize my images without it affecting the thumbnail page.

The padding on the gallery allows it to sit inline with the text on the left. But when viewing single images it makes them full bleed when ideally I'd still like the images to have more space around them. Thanks.

You want increase space around image?