make sure background cover in any size of screen

src/app/auth/auth.component.scss

@@ -6,6 +6,7 @@ div.parent {
     height: 100vh;
     opacity: 0.95;
     background: url('../../assets/img/body_bg.jpg') no-repeat center center fixed; 
+    background-size: cover;
  }
 
  .form_login {