Unable to change main column width in Suffusion

Not sure if this problem is because of my internet connection, or if my website displays incorrectly on everyone’s computer. Today, the main column has decided to be too narrow, messing up my layouts. I can’t figure out how to reset it.

What layout settings should I use in Suffusion to get the blog to display normally on all computer screens?

https://www.pixel51.com/blog/