Update css/main.css

css/main.css

@@ -59,6 +59,8 @@ span[name="utterance"]:hover {
     background: #FFF68F;
     }
 em.linenumber { 
+    display: inline-block;
+    width: 50px;
 	color:#999;
 	font-style: normal;
 	background:#FFFFFF;