console 命令行工具 X clear
console
<head>
	<meta charset="UTF-8">
	<title>Document</title>
	<style>
 
	polyline{
		stroke:red;	/*颜色*/
		stroke-width:2;	/*半径*/
		stroke-dasharray:1400;	/*总线段长*/
		stroke-dashoffset:1400;	/* 线段未绘制长度 */
		transition:.5s;
		fill:none;	/*内容*/
	}
	svg:hover polyline{
		stroke-dashoffset:0;
	}
	</style>
</head>
<body>
	<svg 
        width="400" 
        height="200" 
        style="border: 2px solid #FEB64E;"  
        viewbox="0 0 800 200"
        preserveAspectRatio="xMidYMid meet">
			<polyline points="9,9 409,9 409,189 9,189 9,9"></polyline>
             <rect x="0" y="0" width="800" height="200" style="stroke: green; stroke-width:2px; fill:none;"></rect> 
	</svg>


<svg 
  style="border: 2px solid #FEB64E;" 
  width="400" 
  height="100"
  viewBox="0,0,600,600" 
  preserveAspectRatio="xMidYMid meet"
>
  <rect x="250" y="250" width="100" height="100" style="stroke: black; stroke-width:2px; fill:blue;"></rect>
  <rect x="0" y="0" width="600" height="600" style="stroke: green; stroke-width:12px; fill:none;"></rect>

</svg>

</body>