article img, p img {
    max-width: 100%;
    margin: .5em 0;
}

#mainNav .navbar-nav > li.nav-item > a.nav-link {
    font-size: 1.2rem;
}

header.masthead .site-heading h1 {
    font-size: 2.5rem;
}
p {
    margin-top: .5em;
}

@media (min-width: 768px) {
    header.masthead .site-heading h1 {
        font-size: 3rem;
    }
}