const int buttonPin = 2;
const int ledPin = 13;

void setup() {
  pinMode(buttonPin, INPUT);  // Button input (uses external 10kΩ pull-down)
  pinMode(ledPin, OUTPUT);    // LED output
}

void loop() {
  int buttonState = digitalRead(buttonPin);

  if (buttonState == HIGH) {
    digitalWrite(ledPin, HIGH);  // LED ON when button is pressed
  } else {
    digitalWrite(ledPin, LOW);   // LED OFF when button is not pressed
  }
}