add needed defaults

Author: cscheid

src/resources/formats/html/bootstrap/_bootstrap-variables.scss

@@ -247,6 +247,16 @@ $bootstrap-version: 5;
 $h1h2h3-font-weight: 600 !default;
 
 // variables required by _brand.yml
+
+// these variables need to have been defined here already
+// and are repeated in the framework's own _variables.scss
+// This will require us to monitor framework changes
+// to avoid drift
+$font-weight-base: 400 !default;
+$small-font-size: 0.875em !default;
+$code-font-size: $small-font-size !default;
+$font-family-monospace: SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace !default;
+
 $font-family-monospace-block: $font-family-monospace !default;
 $font-family-monospace-inline: $font-family-monospace !default;
 $font-weight-monospace: $font-weight-base !default;