diff --git a/inst/reveal.js-4.6.1/dist/theme/ids.css b/inst/reveal.js-4.6.1/dist/theme/ids.css
index 6493e18..d1b4a06 100644
--- a/inst/reveal.js-4.6.1/dist/theme/ids.css
+++ b/inst/reveal.js-4.6.1/dist/theme/ids.css
@@ -30,8 +30,8 @@
   --r-heading1-text-shadow: none;
   --r-heading1-size: 2em;
   --r-heading2-size: 1.35em;
-  --r-heading3-size: 1.1em;
-  --r-heading4-size: 1em;
+  --r-heading3-size: 0.9em;
+  --r-heading4-size: 0.7em;
   --r-code-font: monospace;
   --r-link-color: #2a76dd;
   --r-link-color-dark: #1a53a1;
diff --git a/inst/rmarkdown/templates/revealjs_presentation/resources/default.html b/inst/rmarkdown/templates/revealjs_presentation/resources/default.html
index 5a5ee19..0a6c160 100644
--- a/inst/rmarkdown/templates/revealjs_presentation/resources/default.html
+++ b/inst/rmarkdown/templates/revealjs_presentation/resources/default.html
@@ -80,6 +80,8 @@
       background: rgba(255, 255, 255, 0.85);
     }
 $endif$
+$if(theme-ids)$
+$else$
     .reveal h1 { font-size: 2.0em; }
     .reveal h2 { font-size: 1.5em;  }
     .reveal h3 { font-size: 1.25em;	}
@@ -89,6 +91,8 @@
     .reveal .slides>section>section {
       padding: 0px 0px;
     }
+$endif$
+
 $if(center)$
 $else$
      .reveal .title {