Background Image

body {
	background-image: url("images/universe.jpg");
    height: 400px;
	background-size: cover;
}

We have to use a CSS function like that
background-size: cover;
- with this the image will be fit to the width of the container

Gradients

.img {
	background: linear-gradient(rgb(51, 144, 199), rgb(199, 199, 255));
}