wkhtmltopdf equivalent of flex with -webkit-box

Question

I'm having hard times with wkhtmltopdf. I use the binary version 0.12.

my html version is like this

   // container
   <div name="container" style="display:flex;flex-flow:column;justify-content: flex-end;width:1000px;height:500px;left:10px;top:10px;background-color:yellow;">
        // content
        <h2>title</h2>
        <div style="flex-grow: 1; background-color:green;">
        // some content
        </div>   
    </div>

Massive problem : wkhtmltopdf doesn't work with flex or -webkit-flex

I saw on stackoverflow that the solution would be to use display:-webkit-box instead. Src : Using Flex/CSS with wkhtmltopdf But that doesn't align the divs in column et create a result like this : example of the glitch

What is the proper way to vertically align divs in order to put the green content under the title while still fitting yellow container (and without using flex) ?