Whenever a div is nested inside another div and the nested div is given margin through CSS, the margin is supposed to be set according to the parent/container div.
But I have tried and what actually happens is that the child div's margin is set according to 'last element' rather than the previous div.
<!DOCTYPE html>
<html lang="en">
<head>
<!-- Required meta tags -->
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
<title>Web Dev Checklist - Henry Spike</title>
<!-- Bootstrap CSS -->
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-alpha.6/css/bootstrap.min.css" integrity="sha384-rwoIResjU2yc3z8GV/NPeZWAv56rSmLldC3R/AZzGRnGxQQKnKkoFVhFQhNUwEyJ" crossorigin="anonymous">
<link href="https://fonts.googleapis.com/css?family=Ranga" rel="stylesheet">
<style type="text/css">
#main {
background-color: #93628F;
min-height: 100vh;
height: 100%;
color: white;
font-family: 'Ranga', cursive;
}
#main-heading {
margin-top: 100px;
}
</style>
</head>
<body>
<div id="main">
<div class="container">
<div class="row" id="main-heading">
<div class="col-sm-12 text-center">
<h1>Web Developer Checklist - Henry Spike</h1>
</div>
</div>
</div>
</div>
<!-- jQuery first, then Tether, then Bootstrap JS. -->
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.1.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/tether/1.4.0/js/tether.min.js" integrity="sha384-DztdAPBWPRXSA/3eYEEUWrWCy7G5KFbe8fFjk5JAIxUYHKkDx6Qin1DkWx51bBrb" crossorigin="anonymous"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-alpha.6/js/bootstrap.min.js" integrity="sha384-vBWWzlZJ8ea9aCX4pEW3rVHjgjt7zpkNpZk+02D9phzyeVkE+jo0ieGizqPLForn" crossorigin="anonymous"></script>
</body>
</html>
And the output can be seen on http://www.henryspike.tk/checklist You can see the white space above the background color which implies that margin is being set according to the browser top/previous element.
I even tried this on divs without the bootstrap classes to check to see if this was a Bootstrap Issue. But it outputs the same result
