diff --git a/tailwind.config.js b/tailwind.config.js
index 9f25da91..91c01d77 100644
--- a/tailwind.config.js
+++ b/tailwind.config.js
@@ -27,6 +27,7 @@ module.exports = {
         'bg-concept-spz', 'bg-concept-spz/70',
         'bg-concept-epe', 'bg-concept-epe/70',
         'bg-concept-sfl', 'bg-concept-sfl/70',
+        'bg-concept-ser', 'bg-concept-ser/70',
         'flatpickr-input', 'flatpickr-calendar', 'flatpickr-day', 'flatpickr-day.selected',
         'availability-full-to-none', 'availability-full-to-partial', 'availability-none-to-full',
         'availability-partial-to-full', 'availability-none-to-partial', 'availability-partial-to-none',