titles.css

body {
    counter-reset: hFirst;
}

h1 {
    counter-increment: hFirst;
    counter-reset: hSecond;
}

h2 {
    counter-increment: hSecond;
    counter-reset: hThird;
}

h3 {
    counter-increment: hThird;
    counter-reset: hFourth;
}

h4 {
    counter-increment: hFourth;
}