In XHTML + CSS practice, the margin value is negative.

I have not studied this problem carefully before. I have finally figured it out today. Generally, for example, using Div, we usually set a positive number for the margin of a block-level element, in this case, the size of the margin is calculated from the boder perimeter, and when it is set to a negative number, it is calculated as an internal extension, if the element in the row is to keep up with one element, the position of the element in the horizontal direction starts at the end frame of the margin extension.

Code:

<Div style = "margin-Right:-100px; Background-color: # cccccc; width: 200px;"> 1 </div>

Code:

<Div style = "margin-Right:-100px; Background-color: # cccccc; Height: 100px; width: 200px; float: Left;"> </div>
<Div style = "width: 150px; float: Left; Background-color: # 0033cc; Height: 100px;">

 

<Div style = "background-color: # cccccc; Height: 100px; width: 200px; float: Left;"> </div>
<Div style = "width: 150px; float: Left; Background-color: # 0033cc; Height: 100px;">