CSS uses div to draw a 1px high thin line (IE version 6)_html/css_WEB-ITnose

Problem:
div{
background: #f00;
height: 1px;
}

Purpose: I want to use DIV to make a 1PX high thin line.

*The following IE versions are mainly IE6. The performance of IE7 is basically the same as firefox.

At 100PX and 1PX, FF is normal. But when the height attribute is less than 8px, the IE height remains unchanged. Why does IE recognize 100PX but not 1PX.
Processing method:

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