.swagger-ui .topbar {
    background-color: #000;
    border-bottom: 3px solid #ff0000;
}
.link img {
    content: url(https://51degrees.com/Portals/_default/Skins/51Degrees/img/51.svg);
    width: 150px; /* Width of new image */
    height: 30px; /* Height of new image */
}
.link span {
    content: initial;
}