Update app.css - add missing hsl() (#153)

Missing `hsl()`

Author: Plytas

resources/css/app.css

@@ -127,7 +127,7 @@
     --card: hsl(0 0% 3.9%);
     --card-foreground: hsl(0 0% 98%);
     --popover: hsl(0 0% 3.9%);
-    --popover-foreground: 0 0% 98%;
+    --popover-foreground: hsl(0 0% 98%);
     --primary: hsl(0 0% 98%);
     --primary-foreground: hsl(0 0% 9%);
     --secondary: hsl(0 0% 14.9%);