website/assets/sass/carousel.scss

// FROM https://css-tricks.com/css-only-carousel/

@keyframes tonext {
75% {
    left: 0;
}
95% {
    left: 100%;
}
98% {
    left: 100%;
}
99% {
    left: 0;
}
}

@keyframes tostart {
75% {
    left: 0;
}
95% {
    left: -300%;
}
98% {
    left: -300%;
}
99% {
    left: 0;
}
}

@keyframes snap {
96% {
    scroll-snap-align: center;
}
97% {
    scroll-snap-align: none;
}
99% {
    scroll-snap-align: none;
}
100% {
    scroll-snap-align: center;
}
}

* {
    box-sizing: border-box;
    scrollbar-color: transparent transparent; /* thumb and track color */
    scrollbar-width: 0px;
}

*::-webkit-scrollbar {
    width: 0;
}

*::-webkit-scrollbar-track {
    background: transparent;
}

*::-webkit-scrollbar-thumb {
    background: transparent;
    border: none;
}

* {
    -ms-overflow-style: none;
}

$height: 30rem;

.carousel {
    ol, li {
        list-style: none;
        margin: 0;
        padding: 0;
    }

    position: relative;
    filter: drop-shadow(0 0 10px #0003);
    perspective: 100px;
    
    // define the height of the whole carousel
    height: $height;

}

.carousel__viewport {
    position: absolute;
    z-index: 2;
    top: 0;
    right: 0;
    bottom: 0;
    left: 0;
    display: flex;
    overflow-x: scroll;
    counter-reset: item;
    scroll-behavior: smooth;
    scroll-snap-type: x mandatory;
}

.carousel__slide {
    position: relative;
    flex: 0 0 100%;
    width: 100%;
    counter-increment: item;
    z-index: 1; // important: need to have a base set
}

.slide-content {
    position: absolute;
    width: 100%;
    z-index: 0;

    .slide-image {
        padding: 0;
        margin: 0;
        img {
            border-radius: 2px;
        }
        figcaption {
            font-size: .9rem;
            opacity: 0.9;
            text-align: center;
            margin-top: 1rem;
        }
    }
}

.slide-inner {
}

// .carousel__slide:nth-child(even) {
//     background-color: #99f;
// }

.carousel__slide:before {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate3d(-50%,-40%,70px);
    color: #fff;
    font-size: 2em;
}

.carousel__snapper {
    position: sticky;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    scroll-snap-align: center;
    z-index: 2;
    pointer-events: none; // let the slide content take the pointer events
}

// @media (hover: hover) {
//   .carousel__snapper {
//     animation-name: tonext, snap;
//     animation-timing-function: ease;
//     animation-duration: 4s;
//     animation-iteration-count: infinite;
//   }

//   .carousel__slide:last-child .carousel__snapper {
//     animation-name: tostart, snap;
//   }
// }

@media (prefers-reduced-motion: reduce) {
    .carousel__snapper {
        animation-name: none;
    }
}

.carousel:hover .carousel__snapper,
.carousel:focus-within .carousel__snapper {
    animation-name: none;
}

.carousel__navigation {
    position: absolute;
    z-index: 2;
    right: 0;
    bottom: 1rem;
    left: 0;
    text-align: center;
}

.carousel__navigation-list,
.carousel__navigation-item {
    display: flex;
    justify-content: center;
}

.carousel__navigation-button {
    display: inline-block;
    width: 1.5rem;
    height: 1.5rem;
    background-clip: content-box;
    background-color: #eeeeee;
    box-shadow: inset 0 0 2px black;
    border: 0.25rem solid transparent;
    border-radius: 50%;
    font-size: 0;
    transition: transform 0.1s;
}

.carousel::before,
.carousel::after,
.carousel__prev,
.carousel__next {
    position: absolute;
    top: 0;
    width: 4rem;
    height: 4rem;
    transform: translateY($height/2 - 2rem);
    border-radius: 50%;
    font-size: 0;
    outline: 0;
    z-index: 2;
}

.carousel::before,
.carousel__prev {
    left: -0.5rem;
}

.carousel::after,
.carousel__next {
    right: -0.5rem;
}

.carousel__prev,.carousel__next {
    // make sure that the square on each side is can be interacted with
    pointer-events: visible !important;
}

// the big circle navigation button left and right
.carousel::before,
.carousel::after {
    content: '';
    z-index: 10;
    background-color: transparent;
    opacity: 0.65;
    background-size: 1.5rem 1.5rem;
    background-repeat: no-repeat;
    background-position: center center;
    font-size: 2.5rem;
    line-height: 4rem;
    text-align: center;
    pointer-events: none;
}

.carousel::before:hover, .carousel::after:hover {
    opacity: 1 !important;
}

.carousel::before {
    background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 100 100' xmlns='http://www.w3.org/2000/svg'%3E%3Cpolygon points='0,50 80,100 80,0' /%3E%3C/svg%3E");
}

.carousel::after {
    background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 100 100' xmlns='http://www.w3.org/2000/svg'%3E%3Cpolygon points='100,50 20,100 20,0' /%3E%3C/svg%3E");
}

.carousel__navigation-item {
    display: flex;
    align-items: center;
}

.carousel__navigation-item.enabled {
    .carousel__navigation-button {
        opacity: 0.5;
        background-color: lighten($accent, 0%);
    }
}

@media (max-width: $md-breakpoint) {
    $md-height: 47rem;
    .carousel {
        height: $md-height !important;
    }

    .carousel::before,
    .carousel::after,
    .carousel__prev,
    .carousel__next {
        transform: translateY($md-height - 4.5rem) !important;
    }

    .carousel::next {

    }

}


// layout definitions inside the slides
.layout-grid-image {
    display: grid;
    grid-column-gap: 2rem;


    .image-container {
        margin-top: 1.5rem;
        display: flex;
        align-items: center;
    }
}

.double-image-container {
    display: flex;
}

.layout-grid-image.third {
    grid-template-columns: 3fr 1fr;
}

.layout-grid-image.half {
    grid-template-columns: 1fr 1fr;
}

@media (max-width: $md-breakpoint) {
    .carousel {
        .layout-grid-image.half {
            display: block;
        }

        .layout-grid-image.third {
            display: block;
        }

        .image-container {
            display: flex;
            justify-content: center;
            padding-top: 1rem;
        }

        .slide-image {
            height: 20rem;
            img {
                width: auto;
                height: 100%;
            }
        }
    }
}

@media (max-width: $sm-breakpoint) {
    .carousel {
        .image-container {
            padding-top: 0rem;
        }
        .slide-image {
            height: 16rem;
        }
    }
}