Update SplashViz.scss (#3904)

Author: aokiken

src/components/SplashViz/SplashViz.scss

@@ -27,15 +27,13 @@
 
   &__modules {
     position: absolute;
-    left: 0;
-    right: 0;
-    top: 50%; // vertical center
-    bottom: 0;
+    top: 50%;
+    left: 50%;
     width: 75vw;
     min-width: 550px;
     max-width: map-get($screens, large);
     margin: 0 auto;
-    transform: translateY(-50%); // vertical center
+    transform: translate(-50%, -50%);
     display: none;
 
     @include break {