The gray border is the border of the element that we're applying the SVG background image to.
Resize the window to test the SVG fluidity.
SVG embedded as a background image using CSS
<div class="container"></div>
.container {
box-shadow: 0 0 0 10px #b6bdc3;
width: 50%;
background: #fff;
margin: 0 auto;
/* just to get an apsect ratio same as the SVG's: */
padding-top: 48%;
height: 0;
background-image: url(../img/logo.svg);
background-size: cover;
background-repeat: no-repeat;
}