gallowelds.com/themes/gallo/layouts/partials/catalog-gallery.html

<section id="gallery" class="w-full justify-center">
  <div
    class="carousel-wrapper mx-auto max-w-[900px] md:max-w-[1500px] flex relative justify-center items-center"
  >
    <button
      id="prev"
      class="absolute left-0 top-1/2 transform -translate-y-1/2 w-1/2 h-full text-white flex items-center justify-start pl-8"
    >
      <svg
        xmlns="http://www.w3.org/2000/svg"
        class="fill-current w-6 sm:w-4"
        viewBox="0 0 320 512"
      >
        <path
          d="M9.4 233.4c-12.5 12.5-12.5 32.8 0 45.3l192 192c12.5 12.5 32.8 12.5 45.3 0s12.5-32.8 0-45.3L77.3 256 246.6 86.6c12.5-12.5 12.5-32.8 0-45.3s-32.8-12.5-45.3 0l-192 192z"
        />
      </svg>
    </button>
    <div class="carousel" data-current="0">
      {{ $gallery := .Site.Params.gallery.home }} {{ range $index, $image :=
      $gallery }}
      <img
        src="{{ $image.url | safeURL }}"
        alt="{{ $image.alt }}"
        class="carousel-image h-[20rem] sm:h-[30rem] xl:h-[40rem] w-auto rounded-md"
        data-index="{{ $index }}"
      />
      {{ end }}
    </div>
    <button
      id="next"
      class="absolute right-0 top-1/2 transform -translate-y-1/2 w-1/2 h-full text-white flex items-center justify-end pr-8"
    >
      <svg
        xmlns="http://www.w3.org/2000/svg"
        class="fill-current w-6 sm:w-4"
        viewBox="0 0 320 512"
      >
        <path
          d="M310.6 233.4c12.5 12.5 12.5 32.8 0 45.3l-192 192c-12.5 12.5-32.8 12.5-45.3 0s-12.5-32.8 0-45.3L242.7 256 73.4 86.6c-12.5-12.5-12.5-32.8 0-45.3s32.8-12.5 45.3 0l192 192z"
        />
      </svg>
    </button>
  </div>
  <div
    class="thumbnails flex justify-left 2xl:justify-center mt-2 overflow-x-scroll pb-2"
  >
    {{ $gallery := .Site.Params.gallery.home }} {{ range $index, $image :=
    $gallery }}
    <img
      loading="lazy"
      src="{{ $image.url | safeURL }}"
      alt="{{ $image.alt }}"
      class="thumbnail transition-opacity duration-400 cursor-pointer m-1 h-[5rem] sm:h-[10rem] w-auto rounded-md opacity-20"
      data-index="{{ $index }}"
    />
    {{ end }}
  </div>
</section>

<script>
  document.addEventListener("DOMContentLoaded", () => {
    const carousel = document.querySelector(".carousel");
    const images = Array.from(document.querySelectorAll(".carousel-image"));
    const thumbnails = Array.from(document.querySelectorAll(".thumbnail"));
    const thumbnailContainer = document.querySelector(".thumbnails");

    let currentIndex = 0;

    const showImage = (index) => {
      carousel.dataset.current = index;

      images.forEach((img, i) => {
        img.style.display = i === index ? "block" : "none";
      });

      const thumbnail = thumbnails[index];
      smoothScrollTo(thumbnailContainer, thumbnail);
    };

    const handleButtonClick = (direction) => () => {
      currentIndex = (currentIndex + direction + images.length) % images.length;
      showImage(currentIndex);
      addBorderToThumbnail(currentIndex);
    };

    const addBorderToThumbnail = (index) => {
      thumbnails.forEach((thumbnail, i) => {
        if (i === index) {
          thumbnail.classList.add("!opacity-90");
        } else {
          thumbnail.classList.remove("!opacity-90");
        }
      });
    };

    const smoothScrollTo = (element, targetElement) => {
      let startTime = null;
      const duration = 500;

      const scrollStep = (timestamp) => {
        if (!startTime) startTime = timestamp;
        const progress = Math.min((timestamp - startTime) / duration, 1);

        element.scrollLeft =
          element.scrollLeft +
          (targetElement.offsetLeft -
            element.offsetWidth / 2 +
            targetElement.offsetWidth / 2 -
            element.scrollLeft) *
            0.1 *
            progress;

        if (progress < 1) {
          requestAnimationFrame(scrollStep);
        }
      };

      requestAnimationFrame(scrollStep);
    };

    document
      .getElementById("prev")
      .addEventListener("click", handleButtonClick(-1));
    document
      .getElementById("next")
      .addEventListener("click", handleButtonClick(1));

    thumbnails.forEach((thumbnail, index) => {
      thumbnail.addEventListener("click", () => {
        currentIndex = index;
        showImage(index);
        addBorderToThumbnail(currentIndex);
      });
    });

    showImage(0);
    addBorderToThumbnail(0);
  });
</script>