我是新的 svg 学习者，并尝试使用外部样式表为 svg 文件设置动画，但未能为我的对象“立方体”设置样式。
[index.html 文件]
<head>
<link rel="stylesheet" type="text/css" href="cube.css">
</head>
<body>
<img src="cube-motion.svg" height="350px" />
<div class="logo">
<h1>SVG Cube Animation</h>
</div>
[cube-motion.svg 文件]
<?xml version="1.0" encoding="utf-8"?>
<?xml-stylesheet type="text/css" href="cube.css" ?>
<svg version="1.1" id="Layer_1" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" x="0px" y="0px"
viewBox="0 0 200 200" style="enable-background:new 0 0 200 200;" xml:space="preserve">
<g>
<polygon id="l1" class="st0" points="105.3,92.7 86.3,103.3 67.3,92.9 67.1,71.9 86,61.2 105.1,71.6 "/>
<polyline id="l2" class="st1" points="67.1,71.9 86.2,82.5 86.3,103.3 67.1,93.1 66.9,71.9 "/>
<animateTransform
attributeName="transform"
type="translate"
from="0 0"
to="0 75"
begin="0s"
dur="3s"
repeatCount="indefinite" …