Bootstrap-4 显示类不起作用

Question

I'm working with Bootstrap 4 beta at the moment and everything works fine, but I have one problem... the display classes like d-none, d-inline, d-inline-block... don't have any effect. Everything else works just fine and I don't understand why they don't work.

for example:

<div class="container">
    <div class="row">                
        <div class="col-xs-12">
            <h1 class="bg-success d-inline">Test</h1> <h1 class="bg-success d-inline">Test2</h1>
        </div>
    </div>
</div>

Those h1 elements are still displayed as block elements. has anyone an idea where the problem could be?

Answer 1

Ok I think I found the problem. The CSS file has only the display classes with breakpoints, like d-md-inline... but the overall display classes d-inline, d-block, and so on are missing.