<p> Deskptop 18px, Mobile 17pxfont-family in default tagp {
  font-family: "Nanum Gothic", sans-serif;
}
.font-patua {
  font-family: "Patua One", cursive;
}
below p tag won’t apply Patua One font because of p
<div class="font-patua">
  <p></p>
</div>
instead of Use :root
:root {
  font-family: "Nanum Gothic", sans-serif;
}
.font-patua {
  font-family: "Patua One", cursive;
}