Page Menu (menu 1) showing on 2 lines in Chrome

Here is the link to the site. http://sophia.smith.edu/blog/teachingthearchives/

It looks fine in Safari and Firefox. I tried reducing the screen size in Chrome settings, but that did not work. I am working on a iMac without a track pad, so I have not increased the size that way. I do have some css in the Add HTML/CSS Inserts tab and that is for the border as follows.

div#menu1 {
border: solid 1px #602c26;
}

Any info would be great.