update examples on homepage

src/site/scss/style.scss

 @import url(https://fonts.googleapis.com/css?family=Open+Sans:400|Montserrat:400);
 
 /* Override bootstrap variables */
 $sansFontFamily: 'Open Sans', "Helvetica Neue", Helvetica, Arial, sans-serif !default;
 $baseFontSize: 14px !default;
 $baseLineHeight: 22px !default;
 
 $dartFont: 'Montserrat', sans-serif;
 
 @import "compass_twitter_bootstrap_awesome";
@@ skipping 234 matching lines @@
 .spec-rationale {
   color: blue;
   font-style: italic;
 }
 
 .spec-change {
   background: yellow;
 }
 
 code.highlight {
-  background: yellow;
+  background: lemonchiffon;
+  border: 1px solid yellow;
 }
 
 footer {
   border-top: 1px solid #CECECE;
   background-color: #EFEFEF;
   color: $grayLight;
   font-size: $baseFontSize - 1;
   padding: 70px 0;
   margin-top: 50px;
   ul {
@@ skipping 60 matching lines @@
 @import "syntax";
 @import "tutorial";
 @import "dartisans_live";
 @import "up_and_running_book";
 
 @media print {
   .no-print {
     display: none;
   }
 }