Two ways to implement a thin border in a Web page

Many friends have had the experience of making Web pages, and today, many Web pages are designed to use the table. This is not only conducive to the maintenance of Web pages, at the same time, improve the viewing of the Web page. In many web design styles, the thin border method is essential. Here, I'll briefly talk about how to make a thin border.
When it comes to thin borders, I think there are roughly two ways to make them, the first is to use a nested table, and the second is to use CSS to enforce the definition.

How do I nest in a table? As we all know, with bgcolor, you can define the background color of the table in the table, and use cellspacing to control the extra space of the table cell, if you define two tables, set one of the table backgrounds to all Black, and then nest in this table to define another table with the background set to all white, and put weight=100%. At this point, the two tables overlap, but if the table with black background is defined as a cellspacing=1. So that means the black table has a pixel outer space than the white one, and the white table is on the black table, which results in a thin border. The source code is as follows:
<table border= "0" cellpadding=0 cellspacing=1 bgcolor=black>
<tr>
<td>
<table width= "100%" border= "0" cellpadding=0 cellspacing=0 bgcolor=white>
<tr>
<td>
</td>
</tr>
</table>
</td>
</tr>
</table>

The second is simpler, which is to force definitions with CSS (cascading style sheets), but some older browsers do not support CSS, which may result in a failure to display the desired effect. However, using CSS definition, the statement is very concise, the capacity of the Web page is also small. It is operated by defining the style= "Border-postion:black 1px solid in the 〈td〉 tag of the corresponding smallest unit at the outermost table, where the postion parameter has left, right, top, and bottom. Represents a solid line of 1 pixels wide at the left, right, top, and bottom of the cell.
<table border= "0" bgcolor=white>
<tr>
&LT;TD style= "Border-left:black 1px solid; Border-top:black 1px solid; " >
</td>
&LT;TD style= "Border-top:black 1px solid; Border-right:black 1px solid; " >
</td>
</tr>
<tr>
&LT;TD style= "Border-left:black 1px solid; Border-bottom:black 1px solid; " >
</td>
&LT;TD style= "Border-bottom:black 1px solid; Border-right:black 1px solid; " >
</td>
</tr>
</table>