.content {
    height: 2000px;
    padding: 50px;
}

.fade-in {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 1s ease-out, transform 1s ease-out;
    margin: 500px 0;
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}