UserAgent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_13_1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/61.0.3163.100 YaBrowser/17.10.0.2052 Yowser/2.5 Safari/537.36

Steps to reproduce the problem:
1. Go to https://codepen.io/kizu/pen/QaKjmJ
2. Look at the custom counters

Or

1. Create an ordered list, optionally with a `start` attribute.
2. Add custom styles for the list items by using `counter(list-item)`.

What is the expected behavior?
This counter should start from either the `1` or from the number set by `start` attribute.

What went wrong?
The number the counters start from are wrong by one.

However, when the `value` attribute is used, the value is correct.

Did this work before? N/A 

Does this work in other browsers? N/A

Chrome version: 61.0.3163.100  Channel: n/a
OS Version: OS X 10.13.1
Flash Version: 

Edge browser renders everything in a correct way.

There is a hacky fix/workaround for this issue:

    ol.fix:not(*:root) > li:first-child:not([value]) {
      counter-increment: list-item 0;
    }