Login Module CSS

I'm not finding any documentation regarding CSS. I have a narrow column for my Login module, and the text fields are extending outside of their bounding box. With the column width at 200px, everything fits. But I want to shrink it down to 150px and that's where I get problems. Any suggestions on how to correct this?

A fair note, I'm a graphics artist and not a web developer, so if I missed something obvious, please forgive me. *laughs*

Scratch that. Found the php file in its mod folder. Primitive, but effective.