Legend text overlaps and alignment is thrown off when font size is changed

Can you add better handling of different font sizes for legend text? From what I can tell, the calculation for position of each legend item is based off of a fixed height/width or something. When I change the font size of the ".c3-legend-item text" the different legend items overlap each-other along the X axis and the height is not recalculated to vertically align the color-chip with the vertical center of the text.

Thanks and great project!