One strategy you could try is creating a separate div, applying the background to it, and then wrapping it in anchor tags instead of applying the background directly to the anchor. From my own experience, styling anchors can be more challenging.
Additionally, have you checked if the image is being scaled? Ensure that the image dimensions are exactly as you want them by adjusting them in an image editor and setting the width and height properties for your div like this:
height: y px;
width: x px;
Blurriness in images can often be caused by improper browser scaling. Make sure the image is already sized correctly so that the browser doesn't need to scale it further. It might also be helpful to use developer tools in browsers like Chrome, Safari, or Firefox to inspect any CSS rules affecting the background, height, or width of the div.
If these steps don't resolve the issue, please consider providing a link or a screenshot along with additional code for further troubleshooting.