Improve display of source blocks

scss/partials/_codes.scss

@@ -17,12 +17,28 @@
     overflow: visible;
     margin-top: 1em;
 
+    // Caption
+    label {
+        text-align: center;
+        cursor: text;
+
+        .listing-number {
+            font-weight: bold;
+            color: #343131;
+        }
+    }
+
     // Copy Button
     div.src-copy {
         @include src-box;
         line-height:1.5;
         right: 10px;
         cursor: pointer;
+
+        // When button is clicked
+        &.src-copied {
+            background-color: #d6e9ff;
+        }
     }
 
     // Code Block
@@ -54,6 +70,7 @@
         &.src-python:before     { content: 'Python'; }
         &.src-latex:before      { content: 'LaTeX'; }
         &.src-matlab:before     { content: 'Matlab'; }
+        &.src-bibtex:before     { content: 'BibTeX'; }
     }
 }