body {
  background: #007bff;
  background: linear-gradient(to right, #0062E6, #33AEFF);
   background: url("1713879.jpg") no-repeat center center fixed; 
  -webkit-background-size: cover;
  -moz-background-size: cover;
  -o-background-size: cover;
  background-size: cover; 
}

.center {
  border: 0px solid;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  padding: 10px;
  font-size: 8vw;
  font-family: Verdana;
  font-weight: bold;
  color: #FFF;
   text-shadow: -2px 0 black, 0 2px black, 2px 0 black, 0 -2px black;
}