JSFiddle - React, Tailwind, and code Playground

HTML

<div class="favorite">
            <form action="post">
                <input type="submit" class="btnFav" title="Favoritar" value="" />
            </form>
        </div>

CSS

.favorite{
    width: 100%;
    height: 40px; 
}
input[type="submit"] {
    border: none;
    outline:none;
}

.btnFav
{
    background: url(http://imgur.com/CagOuFx.png) no-repeat;
    background-repeat: no-repeat;
    margin-left: 100px;
    margin-right: 40px;
    height: 30px;
    width: 30px;
}

.btnFav:hover,
.btnFav:focus {
    background: url(http://imgur.com/pb27ENk.png)  no-repeat; border: none;
}