Full screen Small screen Help?

Today something happened in my Dashboard that cased My words to get so small I can not hardly read them and my website theme changed from full screen to a small screen. I know I must of hit or clicked something by accident and I can not find where to take it back to full screen with large text. I have 4 websites with you-WordPres and I checked the other 3 and they are all still normal full screens. so I know I did something by accident in the dashboard of this site. My site in question is sevendaywitness.com Please help….. Don Gianino….. Thanks