CSS漸變外框

HTML

<div>
test
</div>

CSS

div{
  border: 4px solid transparent;
  border-radius: 16px;
  background-clip: padding-box, border-box;
  background-origin: padding-box, border-box;
  background-image: linear-gradient(to right, #e8eb6a, #11a8ef), linear-gradient(90deg, #3a41E9, #ae8AEF);
}

效果