diff --git a/flake.nix b/flake.nix
index 6a0b047..0f69e02 100644
--- a/flake.nix
+++ b/flake.nix
@@ -58,6 +58,7 @@
             django
             markdown
             bleach
+            tinycss2
           ];
           
           doCheck = false; # Skip tests during build
@@ -268,6 +269,7 @@
           # Markup and styling
           markdown
           bleach
+          tinycss2
           
           # Data handling
           pydantic