Apply to all child

Is this code possible?

#myDiv
{
   p
   {
      color:red;
   }
   h1
   {
      color:blue;
   }
}

What I want is to apply style to all child elements inside #myDiv.
That's the way I want to do it.
I know that it can be done like #myDiv > p, but the problem is that I have a lot of lines and I would just like to do it in this or similar way.