Logo on Mobile/Tablet doesn't scale correctly

Hello Catchthemes-Team, I'm really enjoying your theme so far, good work! However, I was just setting up my new blog right now when I encountered some weird scaling issues with my logo on mobile resolutions. It appears very wide and somewhat distorted. The quadratic shape is gone. Could some Custom CSS fix this? Here are my current CSS-Inputs

#header-right-search { display: none; }

p {
  -moz-hyphens: none;
  -ms-hyphens: none;
  -webkit-hyphens: none;
  hyphens: none;
}
#masthead .wrapper {
    text-align: center;
}
#site-branding {
    display: inline-block;
    float: none;
    margin: 0 auto;
}

#masthead .wrapper {
    position: relative;
}

@media screen and (min-width: 960px) {
	.sidebar-header-right {
    position: absolute;
    right: 0;
    top: 0;
}

#masthead {
padding: 5px 0;
}

mattscheiben-talk.de Thanks in advance!