Here's my blog: http://intangerine.x10.mx
The headline font is a Google webfont that came with the theme, called "Raleway" (http://www.google.com/fonts/specimen/Raleway), which looks really good on Thin 100, but today it suddenly changed to Medium 500.
This happened after I downloaded Raleway and installed it onto my computer, but it had nothing to do with my blog or WordPress.
Also, this problem is only on Chrome. On other browsers (like Firefox) it's normal.
Anyone know how to fix this?