PostLinks.css

.post-links a {
    display: block;
    text-align: center;
    text-decoration: none;
    background-color: #495057;
    color: white;
    padding: 0.5rem;
    transition: background .3s;
}

.post-links a:hover {
    background-color: #868e96;
}

.post-links a:active {
    background-color: #343a40;
}