HTML Sibling Margins Affected - css

Question

I am trying to set the margin for multiple div elements inside a container div. Here is the HTML:
<div id="container">
<div id="square"></div>
<div id="square1"></div>
<div id="square2"></div>
</div>
Here is the CSS:
#container {
background: #ccc;
width: 200px;
height: 500px;
position: absolute;
overflow: initial;
}
#square {
margin-top: 10px;
height: 50px;
background: green;
}
#square2 {
margin-top: 275px;
height: 55px;
background: black;
}
Now, say I want to edit the margin of square 1. Here is the updated CSS:
#container {
background: #ccc;
width: 200px;
height: 500px;
position: absolute;
overflow: initial;
}
#square {
margin-top: 10px;
height: 50px;
background: green;
}
#square2 {
margin-top: 275px;
height: 55px;
background: black;
}
#square1 {
margin-top: 55px;
height: 50px;
background: red;
}
The margin of square 1 is correct. However, it messes up the margin of square2 because now the top margin is measured from square1 instead of the container div. How do I set the margins of all the sibling divs to where they are measured from the container, regardless of what the other sibling divs are added/removed? Any help would be greatly appreciated.

Answer 1

your will need to give position absolute and width 100%; you can check the js fiddle
Js fiddle
like this for every square
#square {
margin-top: 10px;
height: 50px;
background: green;
position:absolute;
width:100%;
}

Answer 2

You're better off dumping these square divs into a relative div and have an absolute position for each square div. You kind of lucked out because you know the height of each of your square divs.
So your HTML stays the same. The reason you put absolute within the relative is so that the absolute value plays into the #container field instead of body.
Your CSS changes however:
#container {
background: #eee;
width: 200px;
height: 500px;
position: relative;
border: 10px solid green;
}
#square {
margin-top: 10px;
position: absolute;
height: 50px;
left: 0;
right: 0;
background: green;
}
#square2 {
margin-top: 275px;
height: 55px;
position: absolute;
background: black;
left: 0;
right: 0;
}
#square1 {
margin-top: 55px;
position: absolute;
left: 0;
right: 0;
height: 50px;
background: red;
}