效果 (源码网盘地址在最后)
源码
index.html
<!DOCTYPE html>
<html lang="en" >
<head>
<meta charset="UTF-8">
<title>CodePen - Rotating border</title>
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/meyer-reset/2.0/reset.min.css">
<link rel="stylesheet" href="./style.css">
</head>
<body>
<div class="rainbow">
</div>
</body>
</html>
css
body {
display: flex;
justify-content: center;
align-items: center;
height: 100vh;
}
*, *::before, *::after {
box-si