CSS relative + right (or bottom) almost NEVER work - css

Question

I've been writing CSS for quite some time now.
I've noticed that
<div style="position: relative; right: 20%; bottom: 20%;">some text</div>
never works!
relative positioning would work with left and top specified but not with right/bottom. Why?
A quick fix around this is to use "absolute" instead and specify right/bottom in pixels, but I need a reason.
Also, correct me if I'm wrong. Irrespective of whether the external container is positioned absolutely or relatively, does it not make much sense to position something "relative" to the boundaries of that container or should elements inside a container always be positioned "absolute"?
Thank you.

Answer 1

From Absolute vs. Relative - Explaining CSS Positioning
Relative positioning uses the same four positioning properties as absolute positioning. But instead of basing the position of the element upon the browser view port, it starts from where the element would be if it were still in the normal flow.

Answer 2

Relative positioning does work with bottom/right values, just not the way you were expecting:
http://cssdesk.com/RX24j
Think about the position values on relative elements as margins, that the surrounding elements simply ignore. The "margins" will always move the element relative to it's previous position in the normal document flow, but remove it from the normal flow at the same time.
When out of the normal document flow, the surrounding elements act as if it were in it's original position in the normal flow... but it's not. This is why a relative element can overlap it's parent (like in Rel 1).

Answer 3

Did you try this?
<div style="position: relative; right: -20%; bottom: -20%;">some text</div>
or rather
<div style="position: relative; right: -80%; bottom: -80%;">some text</div>

Answer 4

not recommended :
left : 0% //will set it to left
left : 100% //will set it to right => you need to get the width of the element and subtract it using calc ( 100% - width)

Answer 5

To people visiting this old post...
if the element that you are trying to position inside something else has a width or height that is larger than the outer element. The position will ignore left, right, bottom, left.
give it width/height auto.
that was the problem that I had. Hope it helps you too!

Answer 6

remove position left, right, top, bottom from the parents element
and put it in the child as you want
.parent_class
{
background: #ff0000 ;
position: absolute;
transition: 0.8s ease-out;
left:0; //" remove this from here"
top:0; // " remove this from here"
z-index: -1;
}
.child_class
{
width: 0px;
height: 70px;
right: 0; //"now it will work"
bottom: 0;//"now it will work"
}