So, line #20 of vanilla-js-tabs.js says openTab = options.open || 1. I'm no JS expert, but it seems that it should be openTab = options.open || 0. Unless I change the 1 to a 0, it appears to be impossible to set open in the initialization script to the first tab, either by setting it's value to 0 or by simply not setting it. If I don't set it, it ends up selecting the second tab as the default.

Should I be creating a PR for this?

Hi, I found bug in file dist/index.html at line 6: <link rel="stylesheet" href="vanilla-js-dropdown.css"> should be : <link rel="stylesheet" href="vanilla-js-tabs.css">

On http://zoltantothcom.github.io/vanilla-js-tabs/, you have var tabs = new Tab({... in the example where it should be var tabs = new Tabs({.

BTW, thanks for this little library, it's exactly what I was looking for. :)

If the markup of the links in the tabs header is something like this (p.e.):

    <ul class="js-tabs__header">
        <li><a href="#" class="js-tabs__title"><span class="tab-icon">icon1</span><span class="tab-title">Title 1</span></a></li>
        <li><a href="#" class="js-tabs__title"><span class="tab-icon">icon2</span><span class="tab-title">Title 2</span></a></li>
        <li><a href="#" class="js-tabs__title"><span class="tab-icon">icon3</span><span class="tab-title">Title 3</span></a></li>
        <li><a href="#" class="js-tabs__title"><span class="tab-icon">icon4</span><span class="tab-title">Title 4</span></a></li>
    </ul>

Then it doesn't work properly because of the onClick function, changing it to this solves the problem (briefly tested):

    function onClick(e) {
        let titleItem = e.target.closest('.' + titleClass);
        if (titleItem === null) return;
        e.preventDefault();
        openTab(titleItem.getAttribute('data-index'));
    }

Thank you for this simple and effective library.