fix(aio): accessibility items in search and home

Index: Changed h3s to h2s given hierarchy
Index: Aligned text and image blocks to be centered
Index: Announcement bar button darkened for appropriate contrast
Search Results: Changed to list items in unordered list to accommodate accessibility and updated styles accordingly

aio/src/styles/1-layouts/_marketing-layout.scss

@@ -11,6 +11,7 @@
 div[layout=row]{
     display: flex;
     box-sizing: border-box;
+    align-items: center;
 
     @media (max-width: 480px) {
       display: block;

aio/src/styles/1-layouts/_search-results.scss

@@ -5,6 +5,7 @@ aio-search-results {
 .search-results {
     display: flex;
     flex-direction: row;
+    justify-content: space-between;
     overflow: auto;
     padding: 68px 32px 0;
     color: $offwhite;
@@ -34,12 +35,23 @@ aio-search-results {
     flex-direction: column;
     margin: 16px 16px;
     height: 100%;
+
     h3 {
         font-size: 16px;
         font-weight: 400;
         margin: 10px 0px 5px;
         text-transform: uppercase;
     }
+
+    ul {
+        margin: 0;
+        padding: 0;
+
+        li {
+            list-style: none;
+        }
+    }
+
     a {
         font-size: 14px;
         color: $lightgray;
@@ -55,7 +67,6 @@ aio-search-results {
     }
 
     @include bp(tiny) {
-        width: 100%;
         display: block;
     }
 }

aio/src/styles/2-modules/_announcement-bar.scss

@@ -108,7 +108,7 @@ $announcement-bar-width: 784px;
   .button.md-button {
     margin: 0;
     padding: 0 40px;
-    background: $lightgray;
+    background: $mediumgray;
     color: $white;
     float: right;
     font-size: 14px;