<main class="container">
  <section class="section section1"> <button class="modal__btn modal__btn-primary" data-micromodal-trigger="modal-1" role="button">モーダルを開く</button></section>
  <section class="section section2"></section>
  <section class="section section3"></section>

  <!-- ここからモーダルエリアです。 -->
  <div class="modal micromodal-slide" id="modal-1" aria-hidden="true">
    <div class="modal__overlay" tabindex="-1" data-micromodal-close>
      <div class="modal__container" role="dialog" aria-modal="true" aria-labelledby="modal-1-title">
        <header class="modal__header">
          <h2 class="modal__title" id="modal-1-title">
            splideとも併用できます
          </h2>
          <button class="modal__close" aria-label="Close modal" data-micromodal-close></button>
        </header>
        <div class="splide" aria-label="Splideの基本的なHTML">
          <div class="splide__track">
            <ul class="splide__list">
              <li class="splide__slide">
                <img src="https://pengi-n.co.jp/blog/wp-content/uploads/2024/01/splide-05.jpg"  alt="">
              </li>
              <li class="splide__slide">
                <img src="https://pengi-n.co.jp/blog/wp-content/uploads/2024/01/splide-06.jpg"  alt="">

              </li>
              <li class="splide__slide">
                <img src="https://pengi-n.co.jp/blog/wp-content/uploads/2024/01/splide-07.jpg"  alt="">

              </li>

            </ul>
          </div>
        </div>
        <footer class="modal__footer">
          <button class="modal__btn modal__btn-primary" data-micromodal-close aria-label="Close this dialog window">わかった!</button>
        </footer>
      </div>
    </div>
  </div>
</main>
* {
  box-sizing: border-box;
}

img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.section {
  height: 100vh;
}
.section1 {
  background-color: #ccccff;
  display: flex;
  justify-content: center;
  align-items: center;
}
.section2 {
  background-color: #99ccff;
}
.section3 {
  background-color: #ffccff;
}
.splide {
  margin-bottom: 1rem;
}

/**************************\
  Basic Modal Styles
\**************************/

.modal {
  font-family: -apple-system, BlinkMacSystemFont, avenir next, avenir,
    helvetica neue, helvetica, ubuntu, roboto, noto, segoe ui, arial, sans-serif;
}

.modal__overlay {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(0, 0, 0, 0.6);
  display: flex;
  justify-content: center;
  align-items: center;
}

.modal__container {
  background-color: #fff;
  padding: 30px;
  width: 80%;
  max-width: 500px;
  max-height: 100vh;
  border-radius: 4px;
  overflow-y: auto;
  box-sizing: border-box;
}

.modal__header {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.modal__title {
  margin-top: 0;
  margin-bottom: 0;
  font-weight: 600;
  font-size: 1.1rem;
  line-height: 1.25;
  color: #00449e;
  box-sizing: border-box;
}

.modal__close {
  background: transparent;
  border: 0;
}

.modal__header .modal__close:before {
  content: "\2715";
}

.modal__content {
  margin-top: 2rem;
  margin-bottom: 2rem;
  line-height: 1.5;
  color: rgba(0, 0, 0, 0.8);
}

.modal__btn {
  font-size: 0.875rem;
  padding-left: 1rem;
  padding-right: 1rem;
  padding-top: 0.5rem;
  padding-bottom: 0.5rem;
  background-color: #e6e6e6;
  color: rgba(0, 0, 0, 0.8);
  border-radius: 0.25rem;
  border-style: none;
  border-width: 0;
  cursor: pointer;
  -webkit-appearance: button;
  text-transform: none;
  overflow: visible;
  line-height: 1.15;
  margin: 0;
  will-change: transform;
  -moz-osx-font-smoothing: grayscale;
  -webkit-backface-visibility: hidden;
  backface-visibility: hidden;
  -webkit-transform: translateZ(0);
  transform: translateZ(0);
  transition: -webkit-transform 0.25s ease-out;
  transition: transform 0.25s ease-out;
  transition: transform 0.25s ease-out, -webkit-transform 0.25s ease-out;
}

.modal__btn:focus,
.modal__btn:hover {
  -webkit-transform: scale(1.05);
  transform: scale(1.05);
}

.modal__btn-primary {
  background-color: #00449e;
  color: #fff;
}

/**************************\
  Demo Animation Style
\**************************/
@keyframes mmfadeIn {
  from {
    opacity: 0;
  }
  to {
    opacity: 1;
  }
}

@keyframes mmfadeOut {
  from {
    opacity: 1;
  }
  to {
    opacity: 0;
  }
}

@keyframes mmslideIn {
  from {
    transform: translateY(15%);
  }
  to {
    transform: translateY(0);
  }
}

@keyframes mmslideOut {
  from {
    transform: translateY(0);
  }
  to {
    transform: translateY(-10%);
  }
}

.micromodal-slide {
  display: none;
}

.micromodal-slide.is-open {
  display: block;
}

.micromodal-slide[aria-hidden="false"] .modal__overlay {
  animation: mmfadeIn 0.3s cubic-bezier(0, 0, 0.2, 1);
}

.micromodal-slide[aria-hidden="false"] .modal__container {
  animation: mmslideIn 0.3s cubic-bezier(0, 0, 0.2, 1);
}

.micromodal-slide[aria-hidden="true"] .modal__overlay {
  animation: mmfadeOut 0.3s cubic-bezier(0, 0, 0.2, 1);
}

.micromodal-slide[aria-hidden="true"] .modal__container {
  animation: mmslideOut 0.3s cubic-bezier(0, 0, 0.2, 1);
}

.micromodal-slide .modal__container,
.micromodal-slide .modal__overlay {
  will-change: transform;
}
//splideの設定
const splide = new Splide(".splide");
splide.mount();

//Micromodalの設定
MicroModal.init({ awaitCloseAnimation: true, awaitOpenAnimation: true });

External CSS

  1. https://cdn.jsdelivr.net/npm/@splidejs/splide@4.0.7/dist/css/splide.min.css

External JavaScript

  1. https://unpkg.com/micromodal/dist/micromodal.min.js
  2. https://cdn.jsdelivr.net/npm/@splidejs/splide@4.0.7/dist/js/splide.min.js