updated style of :after to have a line-height of 1

Author: roymckenzie

src/inject/inject.css

@@ -12,6 +12,7 @@
   font-family: monospace;
   font-size: 10px;
   font-weight: bold;
+  line-height: 1;
   padding: 2px 4px;
   position: absolute;
   right: 0;