@keyframes slideIn {
    from {
        opacity: 0;
        transform: translateY(40px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

    header,
    .main {
    opacity: 0;
    animation: slideIn 0.7s ease-out forwards;
    }

    .main {
    animation-delay: 0.15s;
}