#slideshow-bg {
    position: fixed;
    inset: 0;
    width: 100%;
    height: 100vh;
    height: 100svh;
    overflow: hidden;
    z-index: 0;
}

#slideshow-bg .slide {
    position: absolute;
    inset: 0;
    max-width: 100%;
    max-height: 100%;
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    filter: brightness(40%);
    opacity: 0;
    will-change: transform, opacity;
}


#slideshow-bg .s1 {
    background-image: url(../img/slide-bg/img-bgslide-1.jpg);
    animation-delay: 0s;
}

#slideshow-bg .s2 {
    background-image: url(../img/slide-bg/img-bgslide-2.jpg);
    animation-delay: 3s;
}

#slideshow-bg .s3 {
    background-image: url(../img/slide-bg/img-bgslide-3.jpg);
    animation-delay: 6s;
}

#slideshow-bg .s4 {
    background-image: url(../img/slide-bg/img-bgslide-4.jpg);
    animation-delay: 9s;
}