Few css fixes for dark theme

app/assets/stylesheets/highlight.black.scss

@@ -30,7 +30,7 @@
   .highlight .kt{color:#458;font-weight:bold;} /* Keyword.Type */
   .m { color: #0000DD; font-weight: bold } /* Literal.Number */
   .p { color: #eee;  }
-  .s { color: #dd2200; background-color: transparent } /* Literal.String */
+  .s { color: #0AD; background-color: transparent } /* Literal.String */
   .highlight .na{color:#008080;} /* Name.Attribute */
   .highlight .nb{color:#0086B3;} /* Name.Builtin */
   .highlight .nc{color:#ccc;font-weight:bold;} /* Name.Class */
@@ -40,12 +40,12 @@
   .highlight .nf{color:#ccc;font-weight:bold;} /* Name.Function */
   .highlight .nn{color:#79C3E0;font-weight:bold;} /* Name.Namespace */
   .highlight .nt{color:#fc5;} /* Name.Tag */
-  .highlight .nv{color:#008080;} /* Name.Variable */
+  .highlight .nv{color:#FA4;} /* Name.Variable */
   .py { color: #336699; font-weight: bold } /* Name.Property */
   .ow { color: #008800 } /* Operator.Word */
   .w { color: #bbbbbb } /* Text.Whitespace */
-  .mf { color: #0000DD; font-weight: bold } /* Literal.Number.Float */
-  .mh { color: #0000DD; font-weight: bold } /* Literal.Number.Hex */
+  .mf { color: #7AC; font-weight: bold } /* Literal.Number.Float */
+  .mh { color: #7AC; font-weight: bold } /* Literal.Number.Hex */
   .highlight .mi {color:#099;} /* Literal.Number.Integer */
   .mo { color: #0000DD; font-weight: bold } /* Literal.Number.Oct */
   .sb { color: #dd2200; background-color: transparent; } /* Literal.String.Backtick */

app/assets/stylesheets/tree.scss

@@ -10,6 +10,10 @@
       border:1px solid #ccc;
       padding:12px;
       background: #F7F7F7;
+
+      pre { 
+        overflow: auto;
+      }
     }
   }