#define LED_PIN 9
#define BUTTON  2

bool ledState = false;
bool lastButton = HIGH;

void setup() {
  pinMode(LED_PIN, OUTPUT);
  pinMode(BUTTON, INPUT_PULLUP);

  digitalWrite(LED_PIN, LOW); // LED OFF initially
}

void loop() {
  bool currentButton = digitalRead(BUTTON);

  // detect button press
  if (lastButton == HIGH && currentButton == LOW) {
    ledState = !ledState;   // toggle LED
    delay(200);             // debounce
  }

  lastButton = currentButton;

  if (ledState) {
    digitalWrite(LED_PIN, HIGH);  // LED ON
  } else {
    digitalWrite(LED_PIN, LOW);   // LED OFF
  }
}