Set envs to animate on loading only (except PROD) (#18)

Simply update the code with what i've been using lately so it only animate when the `.Loader` is created by react. Except for PROD where animation runs anytime.

Use both the new `:has()` pseudo-class and fallback to regular `:not(:only-child())` for unsupported browser (Firefox)

PREP banner.css

@@ -1,17 +1,20 @@
 @-moz-document domain("ppr-app.supplierxm.salsify.com"),
-domain("ppr-admin.alkemics.com") {
+domain("ppr-admin.supplierxm.salsify.com/") {
     :root {
         --stripe-size: 100px;
-        --color1: hsl(194, 71%, 30%);
-        --color2: hsl(194, 77%, 35%);
-        --duration: 20s;
+        --color1: hsla(194, 71%, 30%, 1);
+        --color2: hsla(194, 77%, 35%, 1);
+        --duration: 1s;
+        --state: paused;
     }
 
     .AuthLayoutFooter,
     .Navbar.navbar.Navbar--PPR.bg-inverse {
-        background: repeating-linear-gradient(-45deg, var(--color2) 25%, var(--color1) 50%, var(--color1) 75%);
+        background: repeating-linear-gradient(-45deg, var(--color2) 25%, var(--color2) 50%, var(--color1) 50%, var(--color1) 75%);
+        background-color: var(--color1);
         background-size: var(--stripe-size) var(--stripe-size);
-        animation: alkegrad var(--duration) linear infinite;
+        animation: alkegrad var(--duration) linear 0s infinite normal var(--state);
+        will-change: background-position;
     }
 
     .AuthLayoutFooter {
@@ -19,6 +22,16 @@ domain("ppr-admin.alkemics.com") {
         --duration: 40s;
     }
 
+    .PageTop>.navbar:where( :has(+ .Loader),
+        :not(:only-child)) {
+        --state: running;
+    }
+
+    .PageTop>.Loader {
+        visibility: hidden;
+        animation: none;
+    }
+
     @keyframes alkegrad {
         from {
             background-position: 0 0;