Set explicit font size for topbar

Author: jsha

templates/style/_navbar.scss

@@ -26,7 +26,8 @@ div.nav-container {
     top: 0;
     position: sticky;
     color: var(--color-navbar-standard);
-    font-family: $font-family-sans;
+    /* The font size must be specified in pixels because the height is specified in pixels. */
+    font: 16px $font-family-sans;
 
     li {
         border-left: 1px solid var(--color-border);