let numbers = [];
let currentIndex = 0;
let totalSum = 0;
let numCount = 3; 

document.getElementById("start-button").addEventListener("click", startFlashAnzan);
document.getElementById("check-button").addEventListener("click", checkAnswer);
document.getElementById("num-select").addEventListener("change", function() {
    numCount = parseInt(this.value); 
});

function startFlashAnzan() {
    numbers = [];
    currentIndex = 0;
    totalSum = 0;
    document.getElementById("result").textContent = "";
    document.getElementById("answer").value = "";

    document.body.style.backgroundColor = "black";
    document.getElementById("number-display").classList.add("white-text");
    document.getElementById("result").classList.add("white-text");
    document.getElementById("focus-text").style.display = "block";

    showNextNumber();
}

function showNextNumber() {
    if (currentIndex < numCount) {
        const num = Math.floor(Math.random() * 100) + 1;
        numbers.push(num);
        totalSum += num;
        document.getElementById("number-display").textContent = num;
        currentIndex++;
        setTimeout(showNextNumber, 200);
    } else {
        document.getElementById("number-display").textContent = "？";
        document.body.style.backgroundColor = "";
        document.getElementById("number-display").classList.remove("white-text");
        document.getElementById("result").classList.remove("white-text");
        document.getElementById("focus-text").style.display = "none";
    }
}

function checkAnswer() {
    const answer = parseInt(document.getElementById("answer").value);
    if (answer === totalSum) {
        document.getElementById("result").textContent = "正解！";
    } else {
        document.getElementById("result").textContent = `不正解。正解は ${totalSum} でした。`;
    }
}