Perfect Simple Full Width Background Inside Container

style.css

.yourelement {
    background-image:url('yourimage.jpg'); // Use background-color for background color
    background-position: center center;
    background-size: cover;
    background-repeat: no-repeat;
    width: 100vw;
    position: relative;
    margin-left: -50vw;
    left: 50%;
}