UX: Welcome bannner and search tweaks for mobile (#32362)

* Hides the welcome banner search in mobile, it's not necessary
  since there is the header search
* Fix an issue where the positioning of the search input for
  the header on mobile was affecting welcome banner search
* Make the welcome font a bit smaller and with less padding so
  it takes up less room on mobile

---------

Co-authored-by: Jordan Vidrine <jordan@jordanvidrine.com>

app/assets/stylesheets/common/base/search-menu.scss

@@ -14,18 +14,8 @@
 $search-pad-vertical: 0.25em;
 $search-pad-horizontal: 0.5em;
 
-.search-menu,
-.search-menu-container {
-  .menu-panel .panel-body-contents {
-    overflow-y: auto;
-  }
-
+.search-menu.glimmer-search-menu {
   .search-input-wrapper {
-    display: flex;
-    align-items: center;
-    justify-content: space-between;
-    gap: 0.25rem;
-
     @include breakpoint("mobile-extra-large") {
       --search-input-wrapper-padding: 0.5rem;
       position: fixed;
@@ -38,6 +28,20 @@ $search-pad-horizontal: 0.5em;
       z-index: z("base");
     }
   }
+}
+
+.search-menu,
+.search-menu-container {
+  .menu-panel .panel-body-contents {
+    overflow-y: auto;
+  }
+
+  .search-input-wrapper {
+    display: flex;
+    align-items: center;
+    justify-content: space-between;
+    gap: 0.25rem;
+  }
 
   .search-input {
     position: relative;

app/assets/stylesheets/common/components/welcome-banner.scss

@@ -35,6 +35,12 @@
       margin-top: 0.5em;
     }
 
+    @include breakpoint("mobile-extra-large") {
+      display: block;
+      padding: 0.5em;
+      margin-top: 0;
+    }
+
     > div {
       margin: 0 auto;
       max-width: 600px;
@@ -44,6 +50,10 @@
       display: flex;
       position: relative;
 
+      @include breakpoint("mobile-extra-large") {
+        display: none;
+      }
+
       .search-menu-container {
         width: 100%;
         min-width: 0;
@@ -72,6 +82,10 @@
       @include breakpoint(tablet) {
         font-size: var(--font-up-4);
       }
+
+      @include breakpoint("mobile-extra-large") {
+        font-size: var(--font-up-2);
+      }
     }
 
     h1,