CSS: How to have a button background image of the same size as the button?

Question

I read this link, and unfortunately, it didn't help me: How to make background image shrink proportionally to fit button size in javascript?

I want to generate a button, whose background will be an image. I want CSS to match the image size to be as big as the button is.

This is the CSS I wrote:

button {
    border: solid;
    background-image: url("../img/download.png");
    background-size: 100%;
}

I don't know why, but I don't see any image in the button background. Do you know how to help me?

Solution

Try background-size: cover;, if I'm understanding what you. Good luck!