First attempt at fixing firefox dark mode (#22)

assets/css/template-styles.css

@@ -1024,3 +1024,13 @@ h1 svg {
       background: none;
   }
 }
+
+::-moz-selection { /* Code for Firefox */
+    background: rgba(0,0,0,.8);
+    color: #fefefe;
+}
+  
+::selection {
+  background: rgba(0,0,0,.8);
+  color: #fefefe;
+}

layouts/partials/head.html

@@ -27,7 +27,7 @@
   <link rel="stylesheet" type="text/css" href="{{ $styles.Permalink }}">
 
   <style id="inverter" media="none">
-    html { filter: invert(100%) }
+    .intro-and-nav, .main-and-footer { filter: invert(100%) }
     * { background-color: inherit }
     img:not([src*=".svg"]), .colors, iframe, .demo-container { filter: invert(100%) }
   </style>