I encountered an issue with this code. It runs smoothly on Firefox 50, but encounters failures on Chrome Version 54.0.2840.99 m (64-bit) on Windows.
.test {
background: url(datas/images/3.jpg) no-repeat center center fixed;
background-size: cover !important;
}
Check out the screenshot from Firefox here: https://i.sstatic.net/3G088.jpg and compare it to the Chrome version here: https://i.sstatic.net/56xWt.jpg