Bootstrap 3 Modal auto size, 30 pix from sides - css

Question

I'm trying to build modal window that will be positioned absolute, 30 pixels from edge of screen.
I've build this css:
.modal {
overflow: hidden;
}
.modal-dialog {
position: absolute;
top: 50px;
bottom: 50px;
left: 50px;
right: 50px;
margin: 0;
}
#media (min-width: 768px) {
.modal-dialog {
width: auto;
margin: 0;
}
}
.modal-footer {
position: absolute;
bottom: 0;
left:0;
right:0;
}
.modal-header, .modal-body, .modal-footer {
padding: 10px;
}
.modal-content {
height: 100%;
border-radius: 0;
-webkit-box-shadow: none;
box-shadow: none;
}
.modal-backdrop {
background-color: #fff;
}
.modal-header .close {
margin-top: 3px;
}
.btn {
border-radius: 0;
}
and my results so far looks like this: http://jsfiddle.net/Misiu/LT3YM/
My modal window is correctly positioned, but modal-body isn't sizing, i would like it to take rest of available height of modal - from header to footer.
I can position absolute modal-body and add top and bottom properties, but I'm wondering if there is a better way of doing this.
My solution for now is this code:
.modal-body {
position: absolute;
top: 46px;
bottom: 54px;
overflow-y: scroll;
}
and demo of what I have:
How can I modify my code better so that modal-body will always be correct height? Is positioning it absolutely only option?

Answer 1

http://jsfiddle.net/LT3YM/4/
You should change the values in .modal-dialog. You can make bottom and right 30px too
.modal-dialog {
position: absolute;
top: 30px;
bottom: 50px;
left: 30px;
right: 50px;
margin: 0;
}
Alternatively, this uses 3%: http://jsfiddle.net/LT3YM/7/
.modal-dialog {
position: absolute;
top: 3%;
bottom: 3%;
left: 3%;
right: 3%;
margin: 0;
}
Looks like this: