Style top banner, add placeholder copy

src/views/splash/beta/top-banner.jsx

@@ -9,11 +9,13 @@ require('./top-banner.scss');
 
 const TopBanner = () => (
     <TitleBanner className="beta-top-banner">
-        <FlexRow>
+        <FlexRow className="beta-top-container column">
+            <h1 className="beta-header">The Next Generation of Scratch</h1>
+            <h3 className="beta-copy">Try out the beta version of Scratch 3.0</h3>
             <a
-                className="call-to-action button"
+                className="beta-try-it button"
                 href="https://beta.scratch.mit.edu/"
-            >Call to Action</a>
+            >Try it!</a>
         </FlexRow>
     </TitleBanner>
 );

src/views/splash/beta/top-banner.scss

 @import "../../../colors";
 
 .beta-top-banner {
-    .call-to-action {
+    background: $ui-orange;
+
+    .beta-header,
+    .beta-copy,
+    .beta-try-it {
         color: $ui-white;
     }
 }