Add background pattern and smooth scrolling effect to welcome page

resources/css/app.css

@@ -22,3 +22,21 @@
     width: auto;
     display: block;
 }
+
+.bg-pattern {
+    position: fixed;
+    inset: 0;
+    background-image: url("data:image/svg+xml,%3Csvg width='40' height='40' viewBox='0 0 10 10' fill='none' xmlns='http://www.w3.org/2000/svg'%3E%3Ccircle cx='5' cy='5' r='0.5' fill='%23999'/%3E%3C/svg%3E");
+    opacity: 0.05;
+    z-index: -1;
+    pointer-events: none;
+    background-repeat: repeat;
+    background-position: 0 0;
+    transition: background-position 2s ease-out;
+}
+
+
+@keyframes moveBackground {
+    from { background-position: 0 0; }
+    to { background-position: 1000px 1000px; }
+}