Firefox and responsive SVG - css

Question

Here is a thing.
I have a 700x700px image that i would need to mask with SVG.
For Chrome and Safari i did that by using -webkit-mask-box-image with external SVG and it works properly.
For Firefox, i used clip-path property, and again, it functions properly.
The responsive part is problem.On Chrome&Safari, that part is working nicely, but on Firefox only the main image is resized, mask stays the same.
I am a complete newbie at this and i tried tons of solutions that i found online and i really couldn’t make it work.
<style>
body {
background: yellow;
}
.img-mask {
-webkit-mask-box-image: url('http://imgh.us/mask_3.svg');
mask-border: url('http://imgh.us/mask_3.svg');
clip-path: url(#mask);
}
</style>
<img src="http://gto-live.com/wp-content/uploads/2015/04/charm-elegance-colorful-sofa-living-room-decor-718x718.jpg" class="img-mask">
enter code here
<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" preserveAspectRatio="xMidYMid" width="700" height="700" viewBox="0 0 700 700">
<clipPath id="mask">
<path d="M718.004,358.999 C718.004,160.726 557.272,-0.007 358.998,-0.007 C160.725,-0.007 -0.007,160.726 -0.007,358.999 C-0.007,557.272 160.725,718.005 358.998,718.005 C557.272,718.005 718.004,557.272 718.004,358.999 Z"/>
</clipPath>
</svg>
Any help would really really be gratefully appreciated!
Fiddle can be found here https://jsfiddle.net/y7zaw4bz/1/

Answer 1

You need to use objectBoundingBox units (and make the path run from 0 to 1) e.g.
body {
background: yellow;
}
img {
width: 100%;
}
.img-mask {
-webkit-mask-box-image: url('http://imgh.us/mask_3.svg');
mask-border: url('http://imgh.us/mask_3.svg');
clip-path: url(#mask);
}
<img src="http://gto-live.com/wp-content/uploads/2015/04/charm-elegance-colorful-sofa-living-room-decor-718x718.jpg" class="img-mask">
<svg preserveAspectRatio="xMidYMid" width="700" height="700" viewBox="0 0 700 700">
<clipPath id="mask" clipPathUnits="objectBoundingBox">
<path transform="scale(0.0014)" d="M718.004,358.999 C718.004,160.726 557.272,-0.007 358.998,-0.007 C160.725,-0.007 -0.007,160.726 -0.007,358.999 C-0.007,557.272 160.725,718.005 358.998,718.005 C557.272,718.005 718.004,557.272 718.004,358.999 Z"/>
</clipPath>
</svg>
Here I've scaled the path to correct the units 0.0014 is roughly 1 / 700