fixed CSS background for mobile.

style.css

@@ -1,11 +1,24 @@
 body{
     background-color: #1C406A;
-    background-image: url("images/background/playstation-minimalism.jpg");
-    background-repeat: no-repeat;
-    background-attachment: fixed;
     font-family: 'Barlow';font-size: 16px;
 }
 
+body:before {
+  content: "";
+  display: block;
+  position: fixed;
+  left: 0;
+  top: 0;
+  width: 100%;
+  height: 100%;
+  z-index: -10;
+  background: url("images/background/playstation-minimalism.jpg") no-repeat;
+  -webkit-background-size: cover;
+  -moz-background-size: cover;
+  -o-background-size: cover;
+  background-size: cover;
+}
+
 a {
     color: #000;
     text-decoration: none;