One observation I've made is that when measuring dimensions in Photoshop for "pixel perfection," the values are typically half of what they need to be in CSS. For example, if I measure something at 60px in Photoshop, it translates to 30px in CSS.
However, this conversion is not always exact. Is there a method to ensure a 100% match so that I don't have to estimate? And what is the reason behind this discrepancy?