styles.css

h1 {
    margin-top: 4em;
    padding-bottom: 0.3em;
    line-height: 1.2;
    border-bottom-width: 2px;
    border-bottom-style: solid;
    border-bottom-color: whitesmoke;
}

h2 {
    margin-top: 3em;
    padding-bottom: 0.3em;
    line-height: 1.2;
    border-bottom-width: 1px;
    border-bottom-style: solid;
    border-bottom-color: whitesmoke;
}

h3 {
    margin-top: 2em;
    text-decoration: underline;
}