CSS Animatable offset-distance Property Example

<!DOCTYPE html>
<html>
<head>
<style>
#container {
    width: 400px;
    height: 180px;
    margin: 20px;
    position: relative;
    margin: auto;
    background-color: #f8f9fa;
    box-shadow: 0 0 10px 0 #aaa;
}

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

img {
    position: absolute;
    z-index: 1;
    width: 70px;
    offset-path: path('M 50 80 C 150 -20 250 180 350 80');
    animation: moveFish 5s infinite;
}

@keyframes moveFish {
    0%    { offset-distance: 0%; opacity: 1; }
    80%  { opacity: 0.9;}
    100%  { offset-distance: 100%; opacity: 0; }
}
</style>
</head>
<body>

<h1>Animatable 'offset-distance'  Property</h1>
<hr>

<p>Fish moves along the path using the offset-distance property, which is animatable.</p>
  
<div id="container">
  <img id="fish1" src="images/fish.png" 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>

</body>
</html>