The good news here is that IE11, Chrome, Firefox and Safari all support the newest Flexbox standard. It's pretty simple to bring in IE10 support with the older

The good news here is that IE11, Chrome, Firefox and Safari all support the newest Flexbox standard. It's pretty simple to bring in IE10 support with the older syntax. Forget about the older box layout in Firefox that was built for XUL and earlier implantations in WebKit and gecko. Those have some horrible and surprising bugs and incompatibilities.