improve example style

Style buttons which switch themes with colour and background from it's theme.

Author: pau4o

css/simple-css-switch.css

@@ -20,10 +20,22 @@
     border-color: #a6a659;
 }
 .s-css-s--active-style {
-    border: 0 none;
+    border-style: inset;
 }
 .s-css-s--active-style:before {
     content: '▶';
     position: relative;
     left: -.5em;
 }
+.s-css-s-main-css {
+    color: #eee;
+    background-color: #2c2c2c;
+}
+.s-css-s-red-css {
+    color: #dcd;
+    background-color: #2e0505;
+}
+.s-css-s-green-css {
+    color: #ddd;
+    background-color: #122112;
+}