SSI Files in SSI Files - Rendering of CSS in Wappler

I have just partitioned my index.php file to have an SSI file (ssi_activity.php) which now includes another SSI (ssi_event.php) file…

And while I can see the rendering of my CSS in the first level of SSI (ssi_activity.php) I cannot now see it in the second level (ssi_event.php).

Is there anything I can change to fix this?

Or if I change my design to be routed, so I turn ssi_activity.php into a routed page and then use an SSI to include ssi_event.php will that make the CSS render for ssi_event.php?