css - how to align a div between a position absolute and relative -

I have 3 divs at the top of the first diva position, and the second one is below the div and its position is complete. There is also a third div which I want to be in between I want that the third div is in the middle, so that there is no difference in the height of my browser, I want it to be 20px padding depending on first and second To be paired with

  mid-box {padding: 20px; } .top-box {width: 265px; Status: Relative; Margin: 0 px auto; }. Bottom-box {width: 25%; Padding: 12px 0 12px; Status: Completed; Bottom: 0 pixels; Minimum width: 300px; }    
 
 
 The difference on this one question is often asked on SO, the fact is That you want 20px margin is irrelevant. It is a composite structure that can be difficult.  
 I think it meets your needs You may have to make an agreement that is setting a fixed height on your header and footer.  
  
  .top-box {height: 60px; Status: Relative; } .middle-box {status: absolute; Top: 70px; Bottom: 80px; Left: 20px; Correct: 20px; Margin: 20 px 0; } .bottom-box {height: 56px; Padding: 12px 0 12px; Status: Completed; Bottom: 0 pixels; }