Yep, Admonitions are fully customizable/targetable using CSS snippets. For example, if you created a “note” admonition ad-note, the parent element will receive the .admonition-parent.admonition-note-parent CSS classes and the Admonition itself will receive the .admonition.admonition-note CSS classes.
So, if you wanted to globally set the font for all admonition types, you could do:
.admonition {
font-family: "Roboto";
}
or, just note Admonitions:
.admonition-note {
font-family: "Roboto";
}