sidebar form overlaps

I have the form in my sidebar and have modified the div width to 240 and 28 characters. The fields and labels all fit well except for the “message” box. It extends beyond the right edge of widget. Also, the correction text (for example) “wrong captcha” warning does not stay within the margin either. I see no further settings and it seems like this should all be controlled by form div width.

How to fix?

https://www.ads-software.com/extend/plugins/si-contact-form/