Custom CSS issue testimonials spacing

Hey, folks,

I’ve got a small CSS issue that I can’t figure out. My Sela-based front page (http://textilisconservation.com) displays two blockquote testimonials, in two columns. For a while I only had one loaded, and I adjusted the white space above it to close up a big white gap. What was originally a 5em margin was set to 0em:
.jetpack-testimonial {
margin: 0em 0 0;
}
That worked well. Now I have added a second testimonial, which has populated the second column. The space above that one is back to being the same (too tall) white space as before. Interestingly (to a neophyte like me), if I cut off the number before the “em” entirely :
.jetpack-testimonial {
margin: em 0 0;
}
The two testimonials are level with each other (Yay) but both have the 5em white space above them (not Yay). I’ve tried tinkering with all the other lines in this area indicating margins or padding without success. Is there some way to make sure both testimonial blockquotes are level with each other, and lose the 5 em I don’t want?
Thanks in advance for all advice!