Fully display background image - css

Question

I'm setting up a site, and want to create a responsive background image but I'm getting only single line with background image. What property should i need to use to make the entire background image to fit?
I created 2 files,
index.html :
<div id="logo">Test</div>
style.css :
#logo {
background-image: url("bg.png");
background-position: center center;
background-repeat: no-repeat;
background-attachment: fixed;
background-size: cover;
}
I tried many times but only single line gets background image. I want the background image to be fully displayed on screen without using height property which i think makes site less responsive.

Answer 1

you should change the height of logo div and set it as full height by adding height:100% for the body and logo div, your code should look like below code
html, body
{
height: 100%;
}
#logo {
background-image: url("bg.png");
background-position: center center;
background-repeat: no-repeat;
background-attachment: fixed;
background-size: cover;
height:100%;
}

Answer 2

If you want the image to have the same height as the screen you can use height:100vh. But if you want only the image full size you can do this like this :
html, body {
height: 100%;
margin: 0;
padding: 0;
}
#image{
max-height: 100%;
max-width: 100%;
}
#text{
position: absolute;
color: white;
top: 0
}
<img id="image" src="https://images.unsplash.com/photo-1528920304568-7aa06b3dda8b?ixlib=rb-1.2.1&ixid=eyJhcHBfaWQiOjEyMDd9&w=1000&q=80">
<div id="text">test</div>