h1:before {
counter-increment:level_1;
counter-reset:level_2;
}
h2:before {
content:counter(" counter(level_2) " ";
counter-increment:level_2;
counter-reset:level_3;
}
h3:before {
content:counter(" counter(level_2) "." counter(level_3) " ";
counter-increment:level_3;
counter-reset:level_4;
}
h4:before {
content:counter(" counter(level_2) "." counter(level_3) "." counter(level_4) " ";
counter-increment:level_4;
counter-reset:level_5;
}
h5:before {
content:counter(" counter(level_2) "." counter(level_3) "." counter(level_4) "." counter(level_5) " ";
counter-increment:level_5;
counter-reset:level_6;
}