css_boxmodel.html

<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Css Box Model</title>
    <style>
        * {
            margin: 0;
            padding: 0;
        }

        .main {
            height: 100px;
            width: 100px;
            border: 2px solid red;
            margin: 10px;
            padding: 10px;
            box-sizing: border-box;
        }

        /* margin collapse concept . the one which is bigger will be the margin */
    </style>
</head>

<body>
    <div class="main"></div>
    <div class="main"></div>
</body>

</html>