.built-with a {
    display: inline-block;
    margin: 30px 0;
    background: transparent url(../images/logo-small.svg) 10px 95% no-repeat;
    background-size: 50%;
    padding: 10px 0 0 13px;
}

.built-with.invert a.mas {
    background: transparent url(../images/logo-small-invert.svg) 10px 95% no-repeat;
    background-size: 50%;
}

.built-with a span {
    visibility: hidden;
}