CA/R Markdown demo: use tabular-nums font variant

Change-Id: Ic2ed726d9b407fa63e1b833ffbe5c63e38da3607
diff --git a/demo/Rmd/style.css b/demo/Rmd/style.css
index 93df502..3eace4d 100644
--- a/demo/Rmd/style.css
+++ b/demo/Rmd/style.css
@@ -21,9 +21,12 @@
     font-size: 18px;
     font-weight: 400;
     font-variant-ligatures: common-ligatures;
+    font-variant-numeric: tabular-nums;
 }
 
-
+th {
+  color: rgb(246, 168, 0);
+}
 
 p {
   hyphens: auto;