Change font in "mobile" menu

Site URL: https://blume-equity.squarespace.com/people

Hi,

I need some help changing fonts in my already Css-customized menu for this website.
Since a mobile menu format wasnt available, I god help from @tuanphan to change it to this mobile menu format.

Now I just need to know how to change the fonts as well to the custom ones I am using on the webiste.

Url: https://blume-equity.squarespace.com/
password: Blume

I also would need to know what code to use to change the fonts to custom ones for the different paragraphs. I was only able to change the headings.
Anyone who knows? For headings I used: 

h1 {font-family: 'brownregular';}
h2 {font-family: 'brownregular';}
h3 {font-family: 'brownregular';}
h4 {font-family: 'brownregular';}

Also, one last question: On the "People" page I used some code to create a lightbox for the "Bio". I doesnt look so nice though and I was wondering if anyone knows where to get nice lightbox-designs? 

Or, is there a code for "Read more" where the text shows after a click or similar?

Thank you so much for any potential help!

to change all elements to above font, use

* {
	font-family: 'brownregula' !important;
}

with read more, use this HTML/CSS + Code Block.

Thank you, so helpful!!!

🙂 I really appreciate it @tuanphan