@keyframes fadeInUpEven {
    from {
        opacity: 0;
        transform: translate(30px, 100px);
    }
    to {
        opacity: 1;
        transform: translate(30px, 0);
    }
}

@keyframes fadeInUpOdd {
    from {
        opacity: 0;
        transform: translate(-30px, 100px);
    }
    to {
        opacity: 1;
        transform: translate(-30px, 0);
    }
}

@supports (animation-timeline: auto) {
    #timeline .item:nth-child(even) {
        animation: fadeInUpEven 1s ease-out both;
        animation-timeline: view();
        animation-range: entry 0% cover 15%;
    }

    #timeline .item:nth-child(odd) {
        animation: fadeInUpOdd 1s ease-out both;
        animation-timeline: view();
        animation-range: entry 0% cover 15%;
    }
}