css3 用 background 实现斜切效果 linear-gradient 使用

<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
<style>
div {
float: left;
height: 30px;
width: 200px;
}
.div-1 {
background: linear-gradient(-45deg, transparent 30px, red 0);
}
.div-2 {
background: linear-gradient(135deg, transparent 30px, green 0, green 140px, transparent 0);
}
.div-3 {
background: linear-gradient(45deg, transparent 30px, green 0);
}
</style>
</head>
<body>
<div class="div-1"></div>
<div class="div-2"></div>
<div class="div-3"></div>
</body>
</html>