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                <div id="trail-container"></div>


                body {
    /* スクロールバーを非表示 */
    overflow: hidden;
    background-color: black;

.trail-image {
    position: absolute;
    width: 30px;
    height: 30px;
    /* 消えるアニメーションと移動アニメーション */
    transition: opacity 0.5s, transform 1s;



                document.addEventListener("DOMContentLoaded", function () {
    // トレイルを表示するコンテナ
    const trailContainer = document.getElementById("trail-container");

    // 画像のパス
    const imagePath =

    // 画像のトレイルを生成する関数
    function createTrailImage(x, y) {
        const img = document.createElement("img");
        img.src = imagePath;
        img.classList.add("trail-image"); = x + "px"; = y + "px";

        // アニメーション: 上に移動してから消える
        setTimeout(() => {
   = "translateY(-100vh)"; // 上に移動
   = 0; // 徐々に透明に
            setTimeout(() => {
                img.remove(); // 画像を削除
            }, 1000); // 移動アニメーションの時間
        }, 50); // トレイルが残る時間

    // マウスカーソルの移動時にトレイルを生成
    document.addEventListener("mousemove", function (event) {
        createTrailImage(event.clientX, event.clientY);