Question

I’m currently making a new theme for my blog and I’m having a problem with the header. See, the header has a fixed position at the top, like a nav bar, and it shrinks when the user scrolls down. However, on some browsers (mainly Chrome, especially for windows), the Twitter icon on the header has a strange flickering behaviour, going down to the next line for 1/10th of a second or so.

I’ve seen lots of things about flickering bugs in Chrome when using transitions but nothing that looks like this (also, the fixes didn’t apply to my situation).
It’s a simple transition on the margin of the icons and the height of the header.

Has anyone seen something similar?

Thanks a lot!

EDIT: recreated it in a Fiddle. The problem is still here: http://jsfiddle.net/PVmgz/

HTML `

    <header>
        <div class="container header">
            <a href="#" title="MangeMonBeat"><div id="logo">Logo</div></a>
            <div class="social">
                <div class="search icon">

                </div>
                <div class="facebook icon">
                </div>
                   <div class="twitter icon">
                   </div>
            </div>
        </div>
    </header>

        <div id="button">Scroll</div>

​`

CSS

header {
    width: 100%;
    height: 98px;
    background: #EEE;
    position: fixed;
    top: 0;
    z-index: 9999;
    -webkit-transition: height, ease-in, 0.4s;
       -moz-transition: height, ease-in, 0.4s;
        -ms-transition: height, ease-in, 0.4s;
         -o-transition: height, ease-in, 0.4s;
            transition: height, ease-in, 0.4s;
}

header.scroll {
    height: 60px;
}
header.scroll .header #logo {
    width: 350px;
    height:50px;
}
header.scroll .header .social {
    margin-top: -2px;
}
header.scroll .header .social .icon {
    margin-left: 2px;
}

.header {
    padding: 5px 10px 0;
}

.header #logo {
    width: 400px;
    height:82px;
    background: #696;
    color:white;
    float: left;
    -webkit-transition: width, ease-in, 0.4s;
       -moz-transition: width, ease-in, 0.4s;
        -ms-transition: width, ease-in, 0.4s;
         -o-transition: width, ease-in, 0.4s;
            transition: width, ease-in, 0.4s;
}

.header #logo img {
    max-width: 100%;
    height: auto;
}

.header .social {
    float: right;
    margin-top: 19px;
    -webkit-transition: margin-top, ease-in, 0.4s;
       -moz-transition: margin-top, ease-in, 0.4s;
        -ms-transition: margin-top, ease-in, 0.4s;
         -o-transition: margin-top, ease-in, 0.4s;
            transition: margin-top, ease-in, 0.4s;
}

.header .social .icon {
    display: inline-block;
    margin-left: 20px;
    width: 51px;
    height: 51px;
    border-radius:999px;
    -webkit-transition: margin-left, ease-in, 0.4s;
       -moz-transition: margin-left, ease-in, 0.4s;
        -ms-transition: margin-left, ease-in, 0.4s;
         -o-transition: margin-left, ease-in, 0.4s;
            transition: margin-left, ease-in, 0.4s;
}

.header .social .icon.facebook {
    position: relative;
    background:#336699;
}

.header .social .icon.twitter {
    position: relative;
    background:#66cccc;
}

Answer 1

So I have a possible explanation for this problem, and some code that definitely fixes it.

The possible explanation is that the shrinking social media icons are being rounded up in size at times. As they’re shrinking it might be calculating a width of, say, 26.6 pixels, when of course it must always display as an integer number of pixels. When it rounds that up to 27 pixels, this knocks the last social media icon to the next level.
If this is correct, it flickers because it will continue to shrink, calculating 26 pixels, which is an O.K. value, and it won’t drop down. But then it immediately goes to 25.9 pixels, which again drops it down.
If this is indeed correct, it’d actually be a bit more complicated than this simple explanation I’m giving (the width of the parent element comes into play), but this is enough to get the idea across.

Anyway, a fix that works is giving the div that holds the icons a width, so that there’s ‘breathing room,’ if you will, for the icons to expand.

Here’s some code that gives it that room, but you’ll need to optimize it for it to display as you want it to.

.header .social {
    ...
    width: 500px;
}

My initial idea for a solution would be the set the width of the this div, then float the icons to the right within it.