CSS style of HR in Firefox

CSS style of HR in Firefox

When the following CSS is used for definition, it works well in IE, but in Firefox, the effect is not ideal. When it is basically possible, the dotted line is not dotted and looks a little rough and looks like a dotted line.

HR {Height: 1px; width = 97%; Border: 1px dashed black; text-align: Left ;}

After modification as follows, both Firefox and IE can be taken into account.

HR {Height: 1px; width = 97%; Border: 0px; border-top: 1px dashed black; text-align: Left ;}