Help with Accordion Markdown

Hello! I've used some simple jquery, CSS, and markdown to create an accordion. There are lots of simple instructions on how to do this online, and it works great. 

The trouble is, it is forcing my section to the full height of having every accordion item expanded. So when nothing is expanded, there is a sea of white space below my accordion. It's the space that would be occupied if every item was expanded. How do I get squarepace to auto-adjust the height of my section to match only what is currently displayed?

https://runsantarun.squarespace.com/race-info-1

Thank you!!

Brilliant. Thank you so much for your help. I know the old Squarepace behaved differently but I didn't know I could use the old section style. Thanks so much for going out of your way to help!!!

I'm already in your debt, but I'd like to ask another one. The solution works in the legacy section, but also, the old sections are the worst, so I'm trying your other method too.

Is this code CSS? Or embedded code block? I have very little actual coding knowledge, so all I can do is copy/paste what you give me and stick where you tell me to and cross my fingers. Currently I can't get it to work. Thanks again!

I couldn't make it work but I decided to go with the legacy solution. I found a way to get it to do the layout I wanted. Thank you again!