resolves #10 set font family on playground editor; move declaration to CSS var

pages/assets/css/_base.css

@@ -20,6 +20,7 @@
   --gray-color-900: #18191f;
   --brand-font-primary: "Inter__subset", "Inter", blinkmacsystemfont, -apple-system, "Segoe UI", "Oxygen", "Ubuntu", "Cantarell", "Fira Sans", "Droid Sans", "Helvetica Neue", "Helvetica", "Arial", sans-serif;
   --brand-font-secondary: "Urbanist__subset", "Urbanist", blinkmacsystemfont, -apple-system, "Segoe UI", "Oxygen", "Ubuntu", "Cantarell", "Fira Sans", "Droid Sans", "Helvetica Neue", "Helvetica", "Arial", sans-serif;
+  --monospace-font: "Source Code Pro__subset", "Source Code Pro", monospace;
 }
 
 html {
@@ -572,6 +573,7 @@ section.try .toggle {
 
 #editorCode .cm-scroller {
   border-radius: 5px;
+  font-family: var(--monospace-font);
 }
 
 #editorCode .cm-scroller::-webkit-scrollbar {
@@ -1760,7 +1762,7 @@ code,
 kbd,
 pre,
 samp {
-  font-family: "Source Code Pro", ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
+  font-family: var(--monospace-font);
   font-weight: 400;
 }