body {
    margin: 0;
    overflow: hidden; /* スクロールバーを非表示にする */
    background-color: #000;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    font-family: 'Arial', sans-serif;
}

.container {
    position: relative;
    width: 100vw;
    height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
}

h1 {
    font-size: 5em;
    color: #fff;
    text-shadow: 
        0 0 7px #fff,
        0 0 10px #fff,
        0 0 21px #fff,
        0 0 42px #0fa,
        0 0 82px #0fa,
        0 0 92px #0fa,
        0 0 102px #0fa,
        0 0 151px #0fa;
    animation: flicker 1.5s infinite alternate;
    z-index: 10;
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    margin: 0;
}

canvas {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: #000;
    z-index: 5;
}

@keyframes flicker {
    0%, 19%, 21%, 23%, 25%, 54%, 56%, 100% {
        text-shadow: 
            0 0 7px #fff,
            0 0 10px #fff,
            0 0 21px #fff,
            0 0 42px #0fa,
            0 0 82px #0fa,
            0 0 92px #0fa,
            0 0 102px #0fa,
            0 0 151px #0fa;
    }
    20%, 24%, 55% {
        text-shadow: none;
    }
}