Below is the generated HTML for with line numbers and without line numbers, respectively.
```html
<!-- Without line numbers -->
<pre class="sourceCode scala">
<code class="sourceCode scala">
<span class="kw">trait</span>
Monad[M[_]]
</code>
</pre>
<!-- With line numbers -->
<table class="sourceCode scala numberLines">
<tr class="sourceCode">
<td class="lineNumbers">
<pre>1</pre>
</td>
<td class="sourceCode">
<pre>
<code class="sourceCode scala">
<span class="kw">trait</span>
Monad[M[_]]
</code>
</pre>
</td>
</tr>
</table>
```
The markdown used is:
```
~~~~ { .scala }
trait Monad[M[_]]
~~~~
~~~~ { .scala .numberLines}
trait Monad[M[_]]
~~~~
```
Notice that without line numbers the outer `pre` has a `sourceCode` class whereas with line numbers the `sourceCode` class is only put in `code` and table-related tags.
In the original `syntax.css` file synax highlighting was only triggered if the `kw` and friends tags were within a `pre.sourceCode` - that means it did not trigger with line numbers. This change removes the requirement for the `pre` prefix so that highlighting is triggered with or without line numbers, so long as the code is within *some* `.sourceCode` tag.
