diff -r 024b6541567a -r 36ff0ccd4253 src/pyams_portal/template.py
--- a/src/pyams_portal/template.py	Fri Oct 18 16:55:07 2019 +0200
+++ b/src/pyams_portal/template.py	Wed Sep 02 17:16:04 2020 +0200
@@ -225,6 +225,7 @@
         result = {}
         for slot_name, config in self.slot_config.items():
             result[slot_name] = config.get_width(device)
+            result[slot_name]['css'] = config.get_css_class(device)
         return result
 
     def set_slot_width(self, slot_name, device, width):