Gallery Grid caption text tweak

Site URL: https://www.hubbyco.com/positively-earnest

The caption below images in the gallery grid view is body text by default. Is there a tweak to make it italic and bold without effecting body text elsewhere on site?

Thank you!

Add to Page Settings > Advanced > Header

<style>
.image-slide-title {
    font-style: italic;
    font-weight: bold;
    font-size: 30px !important;
}
</style>