I have a div bloc with a height of 100px that wraps two div blocs. One of these wrapped divs has a height of 10px, while the other has no specified height.
My intention is for "box2" (no height specified) to automatically adjust its height to fill up the remaining space in its containing bloc .
.wrapper{height:100px;}
.box1{height:20px;}
.box2{}
<div class="wrapper">
<div class ="box1"> I have fixed height</div>
<div class ="box2"> I don't have a height</div>
</div>
In equation form:
(height of wrapper) 100px = (h of div1) 20px + (h of div2) Y
where Y is what is needed for both div boxes to fill wrapper.