<!DOCTYPE html>
<html lang="en-US">
<head>
<title>test of border-image-source: linear-gradient with border-image-outset</title>
<style>
div {
  border: 30px solid black;
  width: 90px;
  height: 90px;
  margin: 90px;
}
div.border {
  border-image: linear-gradient(to bottom right, red, blue);
  border-image-outset: 0.5 1 2 60px;
}
div.border30 {
  border-image: linear-gradient(to bottom right, red, blue);
  border-image-outset: 0.5 1 2 60px;
  border-image-slice: 30 30;
}
div.border1260 {
  border-image: linear-gradient(to bottom right, red, blue);
  border-image-outset: 0.5 1 2 60px;
  border-image-slice: 12 60;
}
</style>
</head>
<body>
<div class="border"></div>
<div class="border30"></div>
<div class="border1260"></div>
</body>
</html>