Excerpt text - how to change

Hi folks! I want to use summary blocks for the front page of my site: https://www.speculativeinsight.com/ . As you can see the two columns look different: the left one I created using a text block; the middle one is in a summary block, using the excerpt from a post. I'd like to make the text in the middle one the same as the body text everywhere else, and cannot see how to do that in the Site Styles; I changed the line height for Excerpt text, but that made no difference to the appearance. 

Any help would be appreciated! 

You need to change the summary block body font size from 14px to 16px to match the left text block font size. 

In the Design panel, under site-wide fonts, there is no 'summary block'; there's only excerpt, meta, headings, body, and image/gallery block. Do I need to look somewhere else? 

Also, your line heights do not match, the left and right columns are at 29px and the center is at 20px. 

Hi @derricksrandomviews, thanks for the custom css - I appreciate it. Forgive another question, please: where do I find the design info for the line heights? When I look at the site styles, in the Body section it tells me the line height is 1.8em.

1.8 em is 28.8 pixels. 1.3 em is 20.8 pixels not sure exactly where you would change the summary block line-height but you can try this, 

.summary-excerpt p {
 line-height:  29px !important;
}