Make the rustdoc example links more noticable

Author: mdinger

src/librustdoc/html/static/main.css

@@ -559,14 +559,17 @@ pre.rust .lifetime { color: #B76514; }
 
 .rusttest { display: none; }
 pre.rust { position: relative; }
-.test-arrow {
+a.test-arrow {
     display: inline-block;
     position: absolute;
-    top: 0;
-    right: 10px;
-    font-size: 150%;
-    -webkit-transform: scaleX(-1);
-    transform: scaleX(-1);
+
+    background-color: #4e8bca;
+    color: #f5f5f5;
+    padding: 5px 10px 5px 10px;
+    border-radius: 5px;
+    font-size: 130%;
+    top: 5px;
+    right: 5px;
 }
 
 .methods .section-header {

src/librustdoc/html/static/playpen.js

@@ -28,8 +28,8 @@ document.addEventListener('DOMContentLoaded', function() {
             }
 
             var a = document.createElement('a');
-            a.textContent = '⇱';
             a.setAttribute('class', 'test-arrow');
+            a.textContent = 'Run';
 
             var code = el.previousElementSibling.textContent;