header {  
    background-image: url(../assets/homebg2.jpg);
    background-position: center;
}
.intro .img {
    background-image: url(../assets/energy.jpeg);
    background-position: center;
}
.products .img.img1 {
    background-image: url(../assets/products/4.jpg);
}

.products .img.img2 {
    background-image: url(../assets/products/1.png);
}

.products .img.img3 {
    background-image: url(../assets/products/6.jpg);
}

.products .img.img4 {
    background-image: url(../assets/products/31.jpg);
}