function selectAnswer(index) {
if (index === questions[currentQuestion].correct) {
score++;
}
currentQuestion++;
showQuestion();
}
function startTimer() {
document.getElementById('timer').textContent = timer;
timerInterval = setInterval(() => {
timer--;
document.getElementById('timer').textContent = timer;
if (timer <= 0) {
clearInterval(timerInterval);
endQuiz();
}
}, 1000);
}
function endQuiz() {
clearInterval(timerInterval);
document.getElementById('quiz-screen').classList.add('hidden');
document.getElementById('end-screen').classList.remove('hidden');
document.getElementById('final-score').textContent = score;
}