Replace Tailwind CSS with pure CSS for frontend

justfile

@@ -61,7 +61,7 @@ swag-generate: swag-install
 	@swag init -g internal/server/routes.go -o cmd/docs
 
 [no-cd]
-build: sqlc-generate templ-build tailwind-build swag-generate
+build: sqlc-generate templ-build swag-generate
     @echo "Building..."
     @go build -o main cmd/main.go