Adding Space Under Content Images

I’m tweaking the CSS to improve readability on my website:

https://www.tamiasoutside.com

and the CSS can be seen here:

https://www.tamiasoutside.com/wp-content/themes/paalam/style.css

I’d like to add more space beneath the images in posts. I use a lot of large centered images on my site, but on some displays, the text is crammed right up against the lower edge of the image. What can I add to the CSS to increase this space? I do not want to alter the appearance of images in the sidebar. I’ve tried trial and error in img tags in the CSS without success.

My theme, Paalam, does not include a “tag” (please excuse my lack of the lingo) in the CSS for centering images, so when I include large photos in the posts, I use the <center> tags on the html in order to achieve this.

Thanks very much for help.