fix: hide back to top fab in mobile

Signed-off-by: Innei <[email protected]>

Author: Innei

src/components/layout/root/Root.tsx

@@ -1,5 +1,6 @@
 import { ClientOnly } from '~/components/common/ClientOnly'
 import { BackToTopFAB, FABContainer } from '~/components/ui/fab'
+import { OnlyDesktop } from '~/components/ui/viewport'
 
 import { Content } from '../content/Content'
 import { Footer } from '../footer'
@@ -14,7 +15,9 @@ export const Root: Component = ({ children }) => {
       <Footer />
       <ClientOnly>
         <FABContainer>
-          <BackToTopFAB />
+          <OnlyDesktop>
+            <BackToTopFAB />
+          </OnlyDesktop>
         </FABContainer>
       </ClientOnly>
     </>