W3Schools Tryit Editor

<!DOCTYPE html>
<html>
<head>
<style>
  #frameDiv {
    width: 400px;
    height: 170px;
    margin: 20px;
    position: relative;
    border: solid black 1px;
    background-color: rgb(205, 242, 205);
  }

img {
    position: absolute;
    z-index: 1;
    width: 70px;
    offset: path('M 50 80 C 150 -20 250 180 350 80') 150px -90deg / 0% 50%;
    animation: moveImg 4s 1s 3;
  }

svg {
    position: absolute;
    height: 100%;
    width: 100%;
    left: 0;
    top: 0;
  }

@keyframes moveImg {
    100%  { offset-distance: 100%; }
  }
</style>
</head>
<body>

<h1>The offset property</h1>

<p><mark><strong>Note: </strong> Because this example uses 'offset-anchor' it currently only works with the Firefox browser.</mark></p>

<p>Here, the shorthand property 'offset' is used to set property values for offset-path, offset-distance, offset-rotate and offset-anchor:</p>
<ol>
  <li>The path for the animation is set (offset-path)</li>
  <li>the fish starts moving at a 150 pixels distance from the start of the path (offset-distance)</li>
  <li>the fish is rotated a constant -90 degrees (offset-rotate)</li>
  <li>the fish is connected to the path at the end of its tail, at the very left side of the element, 50% from the top (offset-anchor)</li>
</ol>

</body>
</html>

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<!DOCTYPE html><html><head><style>  #frameDiv {    width: 400px;    height: 170px;    margin: 20px;    position: relative;    border: solid black 1px;    background-color: rgb(205, 242, 205);  }​  img {    position: absolute;    z-index: 1;    width: 70px;    offset: path('M 50 80 C 150 -20 250 180 350 80') 150px -90deg / 0% 50%;    animation: moveImg 4s 1s 3;  }​  svg {    position: absolute;    height: 100%;    width: 100%;    left: 0;    top: 0;  }​  @keyframes moveImg {    100%  { offset-distance: 100%; }  }</style></head><body>​<h1>The offset property</h1>​<div id="frameDiv">  <img src="img_fish.svg" alt="fish">  <svg fill="none" stroke="gray" stroke-width="2" stroke-dasharray="5,5">    <path d="M 50 80 C 150 -20 250 180 350 80" />  </svg></div>​<p><mark><strong>Note: </strong> Because this example uses 'offset-anchor' it currently only works with the Firefox browser.</mark></p>​<p>Here, the shorthand property 'offset' is used to set property values for offset-path, offset-distance, offset-rotate and offset-anchor:</p><ol>  <li>The path for the animation is set (offset-path)</li>  <li>the fish starts moving at a 150 pixels distance from the start of the path (offset-distance)</li>  <li>the fish is rotated a constant -90 degrees (offset-rotate)</li>  <li>the fish is connected to the path at the end of its tail, at the very left side of the element, 50% from the top (offset-anchor)</li>