KF8 and raised cap

I would like to have a "raised cap" for the chapter starting paragraphs of my KF8-book.

is one version I tested. I tried span, various line-height settings etc but Kindle Paperwhite is stubborn: the height of the first line is always computed from the first letter font-size. So the first line has a greater height than the other lines of the paragraph.
I know about the 1.2em / 120% line-height minimum of KF8, but perhaps someone has some css to get nice looking raised caps.

Thanks in advance.