W3Schools Tryit Editor

<!DOCTYPE html>
<html>
<head>
<style>
#container {
  width: 80%;
  aspect-ratio: 2/1;
  margin: auto;
  border: solid black 2px;
  overflow-x: scroll;
  overflow-y: hidden;
  white-space: nowrap;
  scroll-snap-type: x mandatory;
}

.blue {
  background-color: lightblue;
  height: 95%;
  aspect-ratio: 1/1;
}

.green {
  background-color: lightgreen;
  height: 80%;
  aspect-ratio: 1/1;
}

.blue, .green {
  margin: 2px;
  display: inline-block;
  scroll-snap-align: none start;
  scroll-margin-inline-end: 20px;
  direction: rtl;
}
</style>
</head>
<body>

<h3>CSS scroll-margin-inline-end property.</h3>
<p>With the direction property value set to right-to-left, the end of the child elements in the inline direction is changed from right to left, and this also affects the scroll-margin-inline-end property.</p>
<p>In this example, snap position is set to start in the inline direction. To put a margin of 20px where the snap position is, when direction value is right-to-left, margin must be put at the end of the child elements.</p>

<div id="container">
  <div class="blue">Blue</div>
  <div class="green">Green</div>
  <div class="blue">Blue</div>
  <div class="green">Green</div>
  <div class="blue">Blue</div>
  <div class="green">Green</div>
  <div class="blue">Blue</div>
</div>

</body>
</html>

​x
 
<!DOCTYPE html><html><head><style>#container {  width: 80%;  aspect-ratio: 2/1;  margin: auto;  border: solid black 2px;  overflow-x: scroll;  overflow-y: hidden;  white-space: nowrap;  scroll-snap-type: x mandatory;}​.blue {  background-color: lightblue;  height: 95%;  aspect-ratio: 1/1;}​.green {  background-color: lightgreen;  height: 80%;  aspect-ratio: 1/1;}​.blue, .green {  margin: 2px;  display: inline-block;  scroll-snap-align: none start;  scroll-margin-inline-end: 20px;  direction: rtl;}</style></head><body>​<h3>CSS scroll-margin-inline-end property.</h3><p>With the direction property value set to right-to-left, the end of the child elements in the inline direction is changed from right to left, and this also affects the scroll-margin-inline-end property.</p><p>In this example, snap position is set to start in the inline direction. To put a margin of 20px where the snap position is, when direction value is right-to-left, margin must be put at the end of the child elements.</p>​<div id="container">  <div class="blue">Blue</div>  <div class="green">Green</div>  <div class="blue">Blue</div>  <div class="green">Green</div>