XF 2.1 Increase image size in posts - any help?

[BLatt]

I'd like to figure out how I can increase the image size in posts on my site. The embedded images seem to display at 406px wide, but they could be wider. How might I adjust this?
Here's a screen shot of what I'm talking about and what I want. Any help would be appreciated.

 

[BLatt]

I think I got it fixed. Hopefully what I did doesn't mess anything else up.

Add css to extra.css

.fr-view.fr-element img.fr-dii {
max-width: calc(100%);
}

.bbImage {
width: 100% !important;
}