W3School TIY Editor

<!DOCTYPE html>
<html>
<head>
<style>
  #frameDiv {
    width: 400px;
    height: 350px;
    margin: 20px;
    position: relative;
    border: solid black 1px;
    background-color: rgb(205, 242, 205);
  }

img {
    position: absolute;
    z-index: 1;
    width: 70px;
    animation: moveImg 5s 3;
  }

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

#fish1 {
    offset-path: path('M 50 80 C 150 -20 250 180 350 80');
    offset-rotate: auto;
  }

#fish2 {
    offset-path: path('M 50 180 C 150 80 250 280 350 180');
    offset-rotate: auto 90deg;
  }

#fish3 {
    offset-path: path('M 50 280 C 150 180 250 380 350 280');
    offset-rotate: 90deg;
  }

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

<h1>offset-rotate 属性</h1>

<p><b>第一条鱼</b> 的旋转方向与其移动方向一致。这是默认行为。</p>
<p><b>第二条鱼</b> 的旋转方向比其移动方向顺时针多 90 度。</p>
<p><b>第三条鱼</b> 始终向下旋转 90 度。</p>

</body>
</html>