fix: light mode button visibility by adding film colour palette

Squash merged after review. Build/lint/typecheck all pass. Adds film colour palette to Tailwind config for proper light mode visibility.

Author: Shivansh181003

tailwind.config.ts

@@ -16,6 +16,19 @@ const config: Config = {
       colors: {
         background: "var(--background)",
         foreground: "var(--foreground)",
+        film: {
+          50: "#fdf3f4",
+          100: "#fbe5e7",
+          200: "#f6c7cb",
+          300: "#f09ea5",
+          400: "var(--film-400)",
+          500: "#eb4f5b",
+          600: "var(--film-600)",
+          700: "#c22733",
+          800: "#a1232d",
+          900: "#862228",
+          950: "#480f13",
+        },
       },
     },
   },