diff --git a/inst/reveal.js-5.2.1/css/theme/source/ids.scss b/inst/reveal.js-5.2.1/css/theme/source/ids.scss
index c1068ac..9fd8e45 100644
--- a/inst/reveal.js-5.2.1/css/theme/source/ids.scss
+++ b/inst/reveal.js-5.2.1/css/theme/source/ids.scss
@@ -739,6 +739,10 @@
   font-family: 'Fira Sans Condensed', sans-serif;
   font-weight: 400;
   font-size: 16px;
+  // Fira Sans Condensed ships proportional figures by default, so the digits
+  // in neighbouring rows do not line up; tabular numbers (tnum) fix the digit
+  // widths and align numeric table columns vertically.
+  font-variant-numeric: tabular-nums;
 }
 
 .reveal table.dataTable {