You may notice that your website seems well-formatted in Firefox or Opera, they follow every CSS properties you designed, but it seems not the same thing in Chrome, especially the font size.
In Chrome, there's a restriction on minimum font size, you can move the restriction with the following steps:
1. Enter "Customize and control Google chrome":
2. Click "Show advanced settings":
3. Click "Customized fonts":
4. Find "Minimum font size":
5. Lower the limit of "Minimum font size", for instance, 8 pixels:
And don't forget to click "Done" to save it.
Now, It's all done.