Route mobile fundamentals to dedicated page

styleguide.css

@@ -1724,16 +1724,6 @@ section + section {
   gap: var(--spacing-small);
 }
 
-.sg-card-list-page-mobile-detail {
-  display: none;
-  flex-direction: column;
-  gap: var(--spacing-large);
-}
-
-.sg-card-list-page-mobile-detail[hidden] {
-  display: none;
-}
-
 .sg-card-list-page > * + * {
   margin-top: var(--spacing-large);
 }
@@ -1770,14 +1760,6 @@ section + section {
     display: none;
   }
 
-  .sg-card-list-page-mobile-detail {
-    display: flex;
-  }
-
-  .sg-card-list-page-mobile-detail[hidden] {
-    display: none;
-  }
-
   .sg-card-list-page__intro-card.sg-card {
     align-self: stretch;
     width: 100%;