500 Internal Server Error, site lost, help!

I was trying to add a “print this page” feature to a site that was working great. The installation involved adding a few lines to .htaccess via admin/manage/files.

I copy-pasted the new code, clicked on update, and now I can’t get into any page on the site or the wp-admin pages. WTF?!

Can’t find .htaccess with my ftp program.

Tried uploading the site from my local copy. No change.

This is inre: http://enviro.us/

TIA!