A button is embedded in the link tag in jsp. The css of the button is to introduce an image. How to make the button appear vertically centered_html/css_WEB-ITnose

A button is embedded in the link tag in jsp. The css of the button is to introduce an image. How to make the button appear vertically centered? ?
The question is how to center the button vertically? ? Now vertically on top
Here is the current code.

<a href="" ><input type="button"  id="login"  value=""></a>

Reply to discussion (solution)

Picture Relative positioning, or direct padding-top:10px;

Your text needs to be moved down. . The style introduces the picture: background:url(......) center center no-repeat; it is centered on the left, right, top and bottom

Why do you put input in the a tag?