Firefox randomly changes pixel size with no apparent reason
<p>I'm testing a website on multiple browsers.</p>

<p>It works in chrome, Edge, Canary and even IE</p>

<p>However the button is off by about one pixel in Firefox</p>

<p>This is the Button, that is a little bit off, to the left:</p>

<p><img src="https://i.stack.imgur.com/EGmFz.png" alt="this is the Button, that is a little bit off, to the left"></p>

<p>When you press "Ctrl + Shift + I" on that part, to debug it, it says:</p>

<pre><code>border-left-width &gt; 1.6 px
</code></pre>

<p>If you then open the dropdown (to see where it's defined), it tells me, where from the CSS it gets it from:</p>

<pre><code>.settings-accordion .panel-default &gt; 2px
</code></pre>

<p>When I manually change this number, with inline styles, it always rounds down to the next smaller multiple of 0.8.</p>

<p><a href="https://i.stack.imgur.com/uLzcz.png" rel="nofollow noreferrer">this is the screenshot of how firefox interprets the css code</a></p>

<p>If you than manually put it to 2.4 - 3.1 px, it works in this browser, but all the other Browsers are off.</p>

<p>How is this possible?</p>