blog/sass/parts/_anchor.scss

a.zola-anchor {
    margin-left: .5rem;
}

h1,
h2,
h3,
h4,
h5,
h6 {
    &>a.zola-anchor {
        visibility: hidden;
        opacity: 0;
        transition: visibility 0s, opacity 0.5s linear;
    }

    &:hover {
        &>a.zola-anchor {
            visibility: visible;
            opacity: 1;
        }
    }
}