.post-item {
    opacity: 0;
    transform: translateX(50px);
    transition: opacity 2.6s cubic-bezier(0.4, 0, 0.2, 1),
                transform 2.6s cubic-bezier(0.4, 0, 0.2, 1);
    will-change: opacity, transform;
}

.post-item.is-visible {
    opacity: 1;
    transform: translateX(0);
}

.post-item.is-hidden {
    opacity: 0;
    transform: translateX(-100%);
}