Fixed line height and added line hinting.

public/ng/css/gogs.css

@@ -1381,12 +1381,14 @@ The register and sign-in page style
 }
 .code-view .lines-num span {
   font-family: Monaco,Menlo,Consolas,"Courier New",monospace;
-  line-height: 18px;
+  line-height: 1.6;
-  padding: 0 8px 0 10px;
+  padding: 0 10px;  
   cursor: pointer;
   display: block;
-  margin-top: 2px;
+}
-  font-size: 12px;
+.code-view .lines-num span:hover {
+  background-color: #FFFFDD;
+  color: #000000;
 }
 .code-view .lines-code > pre {
   border: none;