#governo li a::before {
    content: url('images/icon-external-link.png');
    position: relative;
    z-index: 10;
    left: -5px;
    top: 0px;
}

#logos li {
    height: 50px;
    display: inline-block;
    margin: 10px 25px;
    vertical-align: middle;
}

img.grayscale{
    -webkit-filter: grayscale(100%);
    -moz-filter: grayscale(100%);
    filter: grayscale(100%);
    transition: all 1s;
}

img.grayscale:hover{
    -webkit-filter: grayscale(0%);
    -moz-filter: grayscale(0%);
    filter: grayscale(0%);
}