css counter-increment unwanted reset when skipping :before

Question

Im having a problem with my counter that im using to get numbers before h3, h4 and h5, like a list. The number should only be visible if the tag has class="count", and its only then it should counter-reset for the header below.

When i skip showing the number on a h3 the h4s counter gets messed upp, and same for skipping h4. Does anyone have any idea why?

body {
  counter-reset: h3
}
h3 {
  counter-reset: h4
}
h4 {
  counter-reset: h5
}
h3.count:before {
  counter-increment: h3;
  content: counter(h3) ". "
}
h4.count:before {
  counter-increment: h4;
  content: counter(h3) "." counter(h4) ". "
}
h5.count:before {
  counter-increment: h5;
  content: counter(h3) "." counter(h4) "." counter(h5) ". "
}
h3:before,
h4:before,
h5:before {
  content: "";
  counter-increment: none
}

<h3 class="count">: should be : 1</h3>
<h4 class="count">: should be : 1.1</h4>
<h5 class="count">: should be : 1.1.1</h5>
<h5>No counter</h5>
<h5 class="count">: should be : 1.1.2</h5>
<h4>No counter</h4>
<h5 class="count">: should be : <span style="color: #ff0000">1.1.3</span></h5>
<h5>No counter</h5>
<h5 class="count">: should be : <span style="color: #ff0000">1.1.4</span></h5>
<h4 class="count">: should be : 1.2</h4>
<h3>No counter</h3>
<h4 class="count">: should be : <span style="color: #ff0000">1.3</span></h4>
<h5 class="count">: should be : <span style="color: #ff0000">1.3.1</span></h5>
<h5>No counter</h5>
<h5 class="count">: should be : <span style="color: #ff0000">1.3.2</span></h5>
<h4>No counter</h4>
<h5 class="count">: should be : <span style="color: #ff0000">1.3.3</span></h5>
<h5>No counter</h5>
<h5 class="count">: should be : <span style="color: #ff0000">1.3.4</span></h5>
<h4 class="count">: should be : <span style="color: #ff0000">1.4</span></h4>
<h3 class="count">: should be : 2</h3>
<h5 class="count">: should be : 2.0.1</h5>
<h4 class="count">: should be : 2.1</h4>
<h5 class="count">: should be : 2.1.1</h5>
<h5>No counter</h5>
<h5 class="count">: should be : 2.1.2</h5>

css

body {counter-reset: h3}
h3 {counter-reset: h4}
h4 {counter-reset: h5}

h3.count:before { counter-increment: h3; content: counter(h3) ". "}
h4.count:before { counter-increment: h4; content: counter(h3) "." counter(h4) ". "}
h5.count:before { counter-increment: h5; content: counter(h3) "." counter(h4) "." counter(h5) ". "}

h3:before, 
h4:before, 
h5:before{ content: ""; counter-increment: none } 

html

<h3 class="count">: should be : 1</h3>
<h4 class="count">: should be : 1.1</h4>
<h5 class="count">: should be : 1.1.1</h5>
<h5>No counter</h5>
<h5 class="count">: should be : 1.1.2</h5>
<h4>No counter</h4>
<h5 class="count">: should be : 1.1.3</span></h5>
<h5>No counter</h5>
<h5 class="count">: should be : 1.1.4</span></h5>
<h4 class="count">: should be : 1.2</h4>

result

1. : should be : 1
1.1. : should be : 1.1
1.1.1. : should be : 1.1.1
No counter
1.1.2. : should be : 1.1.2
No counter
1.1.1. : should be : 1.1.3
No counter
1.1.2. : should be : 1.1.4
1.2. : should be : 1.2

Code: http://jsfiddle.net/6gj2r1jd/

Answer 1

As per your CSS code for the counter, the value of h5 counter should be reset whenever you encounter an h4 tag.

body {counter-reset: h3}
h3 {counter-reset: h4}
h4 {counter-reset: h5} /* this one */

Because of the above code, when the browser encounters the h4 tag with no class (and content as No Counter) the counter value of h5 counter gets reset back to 0. This is the reason why instead of 1.1.3 you had got the value as 1.1.1

<h5 class="count">: should be : 1.1.2</h5>
<h4>No counter</h4> <!-- This line would cause h5 counter to reset -->
<h5 class="count">: should be : 1.1.3</span></h5>

If my understanding of your question is correct, what you actually need is to reset the counter only when the heading tags have class="count". Hence, modifying the counter-reset CSS code like below should solve the problem.

h3.count {counter-reset: h4}
h4.count {counter-reset: h5}

body {
  counter-reset: h3
}
h3.count {
  counter-reset: h4
}
h4.count {
  counter-reset: h5
}
h3.count:before {
  counter-increment: h3;
  content: counter(h3)". "
}
h4.count:before {
  counter-increment: h4;
  content: counter(h3)"." counter(h4)". "
}
h5.count:before {
  counter-increment: h5;
  content: counter(h3)"." counter(h4)"." counter(h5)". "
}
h3:before,
h4:before,
h5:before {
  content: "";
  counter-increment: none
}

<h3 class="count">: should be : 1</h3>
<h4 class="count">: should be : 1.1</h4>
<h5 class="count">: should be : 1.1.1</h5>
<h5>No counter</h5>
<h5 class="count">: should be : 1.1.2</h5>
<h4>No counter</h4>
<h5 class="count">: should be : <span style="color: #ff0000">1.1.3</span></h5>
<h5>No counter</h5>
<h5 class="count">: should be : <span style="color: #ff0000">1.1.4</span></h5>
<h4 class="count">: should be : 1.2</h4>

<h3>No counter</h3>
<h4 class="count">: should be : <span style="color: #ff0000">1.3</span></h4>
<h5 class="count">: should be : <span style="color: #ff0000">1.3.1</span></h5>
<h5>No counter</h5>
<h5 class="count">: should be : <span style="color: #ff0000">1.3.2</span></h5>
<h4>No counter</h4>
<h5 class="count">: should be : <span style="color: #ff0000">1.3.3</span></h5>
<h5>No counter</h5>
<h5 class="count">: should be : <span style="color: #ff0000">1.3.4</span></h5>
<h4 class="count">: should be : <span style="color: #ff0000">1.4</span></h4>

<h3 class="count">: should be : 2</h3>
<h5 class="count">: should be : 2.0.1</h5>
<h4 class="count">: should be : 2.1</h4>
<h5 class="count">: should be : 2.1.1</h5>
<h5>No counter</h5>
<h5 class="count">: should be : 2.1.2</h5>