Tự code rồi chạy thử... Chạy Thử

<!DOCTYPE html>
<html>
<head>
<title>Code Thuộc tính margin-block-start trong CSS</title>
<style>
*{-webkit-box-sizing: border-box; -moz-box-sizing: border-box; box-sizing: border-box;}
div {width:100%; float:left; height:auto;border:1px solid red}
div.divcha{margin-top:10px;}
p {background:green;margin:0px;padding:0px;color:#fff}
</style>
</head>
<body>
<h1>Code Thuộc tính margin-block-start trong CSS</h1>

<div class="divcha"><p style="margin-block-start: 20px" >margin-block-start: 20px</p></div>

<div class="divcha"><p style="margin-block-start: 5%" >margin-block-start: 5%</p></div>

<div class="divcha"><p style="margin-block-start: 0px" >margin-block-start: 0px</p></div>

<div class="divcha"><p style="margin-block-start: 0" >margin-block-start: 0</p></div>

<div class="divcha"><p style="margin-block-start: auto" >margin-block-start: auto</p></div>

<div class="divcha"><p style="margin-block-start: revert" >margin-block-start: revert</p></div>

<div class="divcha"><p style="margin-block-start: -5px" >margin-block-start: -5px</p></div>

<div style="margin-block-start: 20px" >margin-block-start: 20px</div>

</body>
</html>

Code Thuộc tính margin-block-start trong CSS nằm trong bài viết Thuộc tính margin-block-start trong CSS