Css Top Percentage. I dont know why they use the width of the parent to specify the margin top using percentage. 210px and a child padding top.
A percentage of the of the containing elements height for top and bottom or width for left and right auto. The percentage is calculated with respect to the width of the generated boxs containing block. The top property sets the top edge of an element to a unit abovebelow the top edge of its nearest positioned ancestor.
Play it specifies a top margin in percent of the width of the containing element.
And so on with rather idiosyncratic semantics for each css property. I used it to set some fluid type dynamic typography a calculated font size based on minimums maxiums and a rate of change from viewport. The percentage is calculated with respect to the width of the generated boxs containing block. Numerous properties can use percentages such as width height margin padding and font size.