h1{
  counter-reset: ch2 0;
}
h2 {
  counter-reset: ch3 0;
}
h3 {
  counter-reset: ch4 0;
}

.countH ~ h1:before {
    content: counter(ch1) ".\0000a0";
}

.countH ~ h2:before {
    counter-increment: ch2;
    content: counter(ch1) "." counter(ch2) ".\0000a0";
}

.countH ~ h3:before {
    counter-increment: ch3;
    content:  counter(ch1) "." counter(ch2) "." counter(ch3) ".\0000a0";
}

.countH ~ h4:before {
    counter-increment: ch4;
    content:  counter(ch1) "." counter(ch2) "." counter(ch3) "." counter(ch4) ".\0000a0";
}