body {
    margin: 0;
    height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    background-color: black;
    color: white;
    font-size: 5rem;
    font-family: 'Helvetica', 'Arial', sans-serif;
    transition: background-color 2s, color 2s; /* フェードアウトのためのトランジション */
}

.container {
    display: flex;
    align-items: center;
}

.cursor {
    display: inline-block;
    width: 10px;
    animation: blink 1s step-end infinite;
}

@keyframes blink {
    0%, 100% {
        opacity: 1;
    }
    50% {
        opacity: 0;
    }
}