update subheading styles on mobile

ui/shared/entities/base/utils.ts

@@ -22,7 +22,7 @@ export function getContentProps(variant: EntityBaseProps['variant'] = 'content')
     // and for the content variant, fontStyle is set in the consumer component
     case 'subheading': {
       return {
-        textStyle: 'heading.md',
+        textStyle: { base: 'heading.sm', lg: 'heading.md' },
       };
     }
   }

ui/snippets/header/HeaderAlert.tsx

@@ -6,7 +6,7 @@ import MaintenanceAlert from './alerts/MaintenanceAlert';
 
 const HeaderAlert = () => {
   return (
-    <Flex flexDir="column" rowGap={ 3 } mb={ 3 } _empty={{ display: 'none' }}>
+    <Flex flexDir="column" rowGap={ 3 } mb={{ base: 6, lg: 3 }} _empty={{ display: 'none' }}>
       <MaintenanceAlert/>
       <IndexingBlocksAlert/>
     </Flex>