.post-navigation .nav-previous a,
.post-navigation .nav-next a {
    display: block;
    color: white;
    background: #353c3f;
    background-repeat: no-repeat;
    background-position: center center;
    background-size: cover;
}
.post-navigation .nav-previous a:hover,
.post-navigation .nav-next a:hover {
    opacity: 0.9;
}
.post-navigation .nav-previous .link-text,
.post-navigation .nav-next .link-text {
    padding: 20px;
    display: block;
    rgba(0, 0, 0, 0.5);
}