Fix line-number and scroll bugs (#33094) (#33095)

Partially backport #33094 

Fix the scroll bug in issue/pr view page.

Fix a JS error when line number exceeds the max

web_src/css/base.css

@@ -693,6 +693,7 @@ input:-webkit-autofill:active,
 
 .ui.dropdown .menu > .header {
   font-size: 0.8em;
+  text-transform: none; /* reset fomantic's "uppercase" */
 }
 
 .ui .text.left {