allow user to see more tags in the reference,

simplify the style declaration for a tag

stylesheets/admin/partials/_popup.sass

@@ -28,7 +28,7 @@ div.popup
   .snippet_description
     border-bottom: 1px dotted silver
     font-size: 95%
-    padding: 12px 0
+    padding: 6px 0
     h4
       color: green
       font-size: 120%
@@ -69,13 +69,8 @@ div.popup
       border: 1px solid #ddd
       color: #666
       font-family: Monaco, "Courier New", Courier, monospace
-      overflow: hidden
+      overflow: auto
       padding: 10px
-    h4
-      color: green
-      font-size: 120%
-      margin-top: 0
-      margin-bottom: 8px
     table
       width: 100%
       th
@@ -104,6 +99,12 @@ div.popup
         margin-bottom: 1em
   .close_link
     text-align: center
+.tag
+  color: green
+  cursor: pointer
+  font-size: 120%
+  margin-top: 0
+  margin-bottom: 8px
 
 div.popup .reference table
   th
@@ -114,4 +115,4 @@ div.popup .reference table
   h2, h3, h4
     color: black
     margin: 0
-    margin-bottom: .5em
+    margin-bottom: .5em