Fix code block style for code preview (#30298)

Fix #30292

To avoid unnecessary style overriding, use "div" instead of "code"

templates/base/markup_codepreview.tmpl

@@ -17,7 +17,7 @@
 					{{- $lineEscapeStatus := index $.LineEscapeStatus $idx -}}
 					<td class="lines-escape">{{if $lineEscapeStatus.Escaped}}<a href="#" class="toggle-escape-button btn interact-bg" title="{{if $lineEscapeStatus.HasInvisible}}{{ctx.Locale.Tr "repo.invisible_runes_line"}} {{end}}{{if $lineEscapeStatus.HasAmbiguous}}{{ctx.Locale.Tr "repo.ambiguous_runes_line"}}{{end}}"></a>{{end}}</td>
 				{{- end}}
-				<td class="lines-code chroma"><code class="code-inner">{{$line.FormattedContent}}</code></td>
+				<td class="lines-code chroma"><div class="code-inner">{{$line.FormattedContent}}</div></td>{{/* only div works, span generates incorrect HTML structure */}}
 			</tr>
 			{{- end -}}
 		</tbody>