.skyline-container {
    position: fixed;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 20%;
    z-index: -5;
    overflow: hidden;
}

.skyline {
    position: absolute;
    bottom: 0;
    left: 0;
    width: 200%;
    height: 100%;
    background-image: url("../images/skyline.png");
    opacity: 0.2;
    animation: skyline-scroll 60s linear infinite;
}

@keyframes skyline-scroll {
    0% {
        transform: translateX(0);
    }

    100% {
        transform: translateX(-50%);
    }
}