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CSS

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HTML 

              
                <div class="scroll-layout">
  <div class="carousel">
    <ul class="content">
      <li></li>
      <li></li>
      <li></li>
      <li></li>
      <li></li>
      <li></li>
      <li></li>
      <li></li>
      <li></li>
      <li></li>
    </ul>
  </div>
</div>
!

CSS 

              
                /* SCROLLER */
/* horizontal scroll snap */
.carousel {
  overflow-x: auto;
  scroll-snap-type: x mandatory;
  overscroll-behavior-x: contain;
  
  @media (prefers-reduced-motion: no-preference) {
    scroll-behavior: smooth;
  }
  
  /* snap to center */  
  & li {
    scroll-snap-align: center;
  }
}


/* SCROLL BUTTONS */
/* create buttons by selecting them and adding content */
.carousel {
  &::scroll-button(*) {
    /* make them round and easy to press */
    inline-size: 48px;
    aspect-ratio: 1;
    border-radius: 1e3px;
    border: 2px solid #999;
    
    /* space from content */
    margin: 5px;
  }
  
  &::scroll-button(*):focus-visible {
    outline-offset: 5px;
  }
  
  &::scroll-button(*):not(:disabled):is(:hover, :active) {
    background-color: Canvas;
  }
  
  &::scroll-button(*):not(:disabled):active {
    scale: 90%;
  }
  
  &::scroll-button(left) {
    content: "⬅" / "Scroll Left";
    grid-area: left; /* place markers in parent grid area */
  }
  
  &::scroll-button(right) {
    content: "⮕" / "Scroll Right";
    grid-area: right;
  }
}




/* SCROLL MARKERS */
/* create marker group */
/* create markers for each item */
.carousel {
  /* create markers 'after' scroller */
  scroll-marker-group: after;

  /* create markers container and own dots layout */
  &::scroll-marker-group {
    grid-area: markers; /* place markers in parent grid area */
    
    /* 15px by 15px horizontal grid - size of dots */
    display: grid;
    place-content: safe center;
    grid: 30px / auto-flow 30px;
    gap: 15px;
    padding: 15px;
    scroll-padding: 15px;
    
    /* handle overflow */
    overflow: auto;
    overscroll-behavior-x: contain;
    scrollbar-width: none;
    scroll-snap-type: x mandatory;
    
    @media (prefers-reduced-motion: no-preference) {
      scroll-behavior: smooth;
    }
  }

  /* a marker for each <li> */
  & > .content > li {
    /* create by adding content */
    &::scroll-marker {
      content: " "; /* empty content is fine, just like ::before */
      
      /* style it as you need */
      border: 1px solid #bbb;
      border-radius: 50%;
      outline-offset: 4px;
      -webkit-tap-highlight-color: transparent;
      
      /* snap if group is overflowing */
      scroll-snap-align: center;
    }
    
    &::scroll-marker:is(:hover, :focus-visible) {
      border-color: LinkText;
    }
    
    &::scroll-marker:target-current {
      background: LinkText;
      border-color: LinkText;
    }
  }
}















@layer support.demo {
  html, body {
    block-size: 100%;
  }
  
  body {
    display: grid;
    place-content: start center;
    margin: 0;
    padding: 10vmin;
  }
  
  .scroll-layout {
    display: grid;
/*     border: 1px dashed gray; */
    
    /* try a different layout =) */
    grid-template-areas: 
      "left scroll right"
      ". markers .";
    
    /* just place items in the grid */
    grid-template-areas: 
      "scroll scroll scroll"
      "left markers right";
    
    grid-template-columns: auto 1fr auto;

    .carousel {
      grid-area: scroll;
    }
  }
  
  .carousel {
    max-inline-size: 80cqi;
    overscroll-behavior-x: contain;
    scroll-behavior: smooth;
  }

  .content {
    display: grid;
    grid: 50vmin / auto-flow 50vmin;
    gap: 15px;
    padding: 0;
    margin: 0;

    > li {
      list-style-type: none;
      border: 3px solid #888;
    }
  }
}
!

JS
!
999px

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