CSS3 Fader Case Study
CSS3 Fader Case Study. The trigger element of fader knob has the highest z-index and opacity:0. For each bar, 50 divs are used with data-perc attribute having values from 0% to 100% with a difference of two so that when you hover on the particular part of the bar, the :before pseudo elements takes the value from data-perc attribute and displays it.