Assuming both the blue and green divs have varying heights, we need to calculate the correct offset of the green div without relying on CSS.
CSS limitations prevent us from positioning an element using data from another element. Therefore, we must manually calculate the offset using a client-side language like Javascript. jQuery simplifies this process with its user-friendly syntax.
To determine the offset, we first find the center of the blue element by dividing its height by 2. Then, we calculate how much the green div should move up so that its top aligns with the center of the blue div. This calculation involves subtracting half of the green div's height from half of the blue div's height: (blue.height / 2) - (green.height / 2).
We can translate this formula into Javascript code:
var center = $('div.blue').outerHeight(true) / 2;
var offset = center - $('div.green').height() / 2;
Finally, we set the calculated offset for the green div:
$('div.green').css({
'margin-top': margin
});
This theory is fascinating, but you probably want to see it in action. Check out the demo here.
Edit:
Remember, jQuery is a cross-browser framework that ensures compatibility even with older browsers. Learn more about its browser support here!