As a heads up, we include this in the Bootstrap docs as an example.
In the latest Safari for Mac, its rendering engine has a little trouble with the long decimal places of our .col-*-1 grid classes, meaning if you have 12 individual columns you'll notice they come up short compared to other rows of columns. We can't do much here (see #9282) but you do have some options:
As of Safari v6.1 for OS X and Safari for iOS v7.0.1, Safari's rendering engine has some trouble with the number of decimal places used in our .col-*-1 grid classes. So if you have 12 individual grid columns, you'll notice that they come up short compared to other rows of columns. We can't do much here (see #9282) but you do have some options:
.pull-right to your last grid column to get the hard-right alignment