On all browsers but Firefox, the following code produces the result shown below:
div
{
white-space: nowrap;
overflow: hidden;
text-overflow: ellipsis;
}
div > span
{
float: right;
background: rgba(255, 0, 0, 0.5);
}
<div>
<span>float!</span>
sukhudfh slduifh dsukf hsludk ksndfgkv nfdkgjnsdk:ndkf n,sldk n:dknv lx:,vc ls:xjlf ,msldkj*nx vo:dkng v:kxnc vl:lj xf, c !lskwf,moslkdwhxfn vmosdxwjxf,vù!sdlxwjf,ù!sldwjlf ,ùpsold v,ùpdlf, w!
</div>

But on Firefox (53) you get:
How do I get Firefox to behave just like the other browsers?