a img {
border-color: white;
/*margin-left: 15em;*/
margin-bottom: 1.75em;
margin-top: 1.75em;
background-color: black;
margin-left: 1em;
border-left-width: 30px;
color: white;
/*margin: 3em 0em 0em 0em;*/
/*border: none;*/
}

The red part is pushing your logo image to the right.