Can you change the font size of the module headings on the home page in Rise?

You can edit the published files to make the headings look however you like. Ideally you'd do this in a new css file (and import that into your index.html file) but to keep it simple you can add the following code straight into the index.html file.

.overview-list__title-content {
 
 font-size: 1.2em;
 color: #4BAAF4;

}

Add the above either to a custom CSS file or to the following section of the index.html file:

@media (max-width: 47.9375em) { /* 768px */
 .brand--max768--background { background-color: #4BAAF4 !important; }
 .brand--max768--border { border-color: #4BAAF4 !important; }
 .brand--max768--color { color: #4BAAF4 !important; }
 }
 <ADD THE ABOVE CODE HERE>

</style>
<div id="app"></div>

The sample code i have provided also gives the heading a color so just remove the color line if you don't want to change that. I used the same color as my custom theme and it looks pretty good I think (you'll find the HEX value for your color scheme in the index file so just copy and paste that). You can also adjust the 1.2em size to whatever you like e.g: 0.8 will be smaller, 1.4 will be bigger and 2.1 will be bigger still.

Here's an example of how it looks: