Animated SVG border-image not honoring border-radius

Question

I'm trying to make an animated border radius via using an SVG with border-image, and round it out with border-radius. I have overflow: hidden; but the border doesn't seem to be affected by this property. I'll give the current code below, and an example of the border styles in a JSFiddle. Any help is appreciated!

    margin: 0 auto;
    height: 80vh;
    font-size: 3vw;
    overflow: hidden;
    border: 5px solid;
    border-image: url(../images/borderAnimation.svg) 5 stretch;
    border-radius: 15px;
    background-color: rgb(70, 70, 70);

JSFiddle: https://jsfiddle.net/madaley/vfunmsr7/

Answer 1

I know this is kind of cheating, but if you could have nested elements then the parent could have a background and the child could mask of the background with a color:

div.wrapper {
  width: 300px;
  height: 200px;
  border-radius: 10px;
  padding: 5px;
  background-image: url(https://www.public.asu.edu/~madaley1/images/borderAnimation.svg);
  display: flex;
  align-items: center;
  justify-content: center;
}

div.wrapper>div {
  width: 100%;
  height: 100%;
  border-radius: 5px;
  box-sizing: border-box;
  background: white;
}

<div class="wrapper">
  <div></div>
</div>