*{padding: 0; margin: 0;}
.bg-img{
  /*full bg img*/
  width: 100%;
  height: 100vh;
/*   background: #161c23 url('http://wallpaper.pickywallpapers.com/1920x1080/white-keyboard-desktop-wallpaper.jpg') no-repeat center;
  background-size: cover; */
  
  /*gradient bg*/
  /*background-image: linear-gradient(gray, blue);*/
  /*background-image: radial-gradient(circle at top, gray, blue);*/
  /*background-image: radial-gradient(circle at top, gray, cornflowerblue, blue); */
  
  /*bg img w/ gradient overlay*/
  background: linear-gradient(to top, #161c23, transparent 100%),
    linear-gradient(#161c23, transparent 100%),
              #161c23 url('https://source.unsplash.com/category/technology/1500x2000') no-repeat center;
}