How do I enlarge the byline title

How would I enlarge the byline title? I tried this css:

.wp-tiles-tile-with-image .wp-tiles-byline-title {
font-size: 30px !important;
}

and it sorta works, but it just paints it, then erases it:

htpp://msd.avwebmaster.com (you’ll see it happen)

HELP!

https://wordpress.org/plugins/wp-tiles/