style(todo-input): improve dark mode placeholder visibility in input field

Author: sajjadmrx

src/layouts/calendar/components/todos/todo-input.tsx

@@ -22,7 +22,7 @@ export function TodoInput({ onAdd }: Prop) {
 				value={text}
 				onChange={(e) => setText(e.target.value)}
 				placeholder="یادداشت جدید..."
-				className="flex-1 px-3 py-2 text-gray-600 placeholder-gray-500 rounded-lg bg-gray-300/50 dark:bg-gray-700/50 focus:outline-none focus:ring-2 focus:ring-blue-500 "
+				className="flex-1 px-3 py-2 text-gray-600 placeholder-gray-500 rounded-lg dark:placeholder-gray-500/80 dark:text-gray-300 bg-gray-300/50 dark:bg-gray-700/50 focus:outline-none focus:ring-2 focus:ring-blue-500 "
 			/>
 			<button
 				type="submit"