fix: tailwind v4 ios 16.4 compatibility issue

src/tailwind.css

@@ -35,6 +35,11 @@
 	button {
 		@apply cursor-pointer;
 	}
+
+	input::placeholder,
+	textarea::placeholder {
+		color: theme(--color-gray-400);
+	}
 }
 
 @custom-variant hover (&:hover);