Extended intersection observer to also hide the fixed share buttons w…

…hen the user has scrolled past the share buttons.

This is because we don't want to show the fixed share buttons in the footer

src/components/button-share/button-share.tsx

@@ -24,31 +24,31 @@ const ButtonShare: React.FC<ButtonShareProps> = ({ className }) => {
     navigator.clipboard.writeText(href);
   };
 
+  // Hide fixed buttons when share button is in view or above viewport
   useEffect(() => {
+    const shareButton = shareButtonRef.current;
     const observer = new IntersectionObserver(
       (entries) => {
-        entries.forEach((entry) => {
-          if (entry.isIntersecting) {
-            setShowFixedButtons(false);
-          } else {
-            setShowFixedButtons(true);
-          }
+        const isIntersecting = entries.some((entry) => entry.isIntersecting);
+        const isAboveViewport = entries.some((entry) => {
+          // return true if the share button is above the viewport
+          return entry.boundingClientRect.top < 0;
         });
+        setShowFixedButtons(!isIntersecting && !isAboveViewport);
       },
       { threshold: 1 }
     );
 
-    const shareButton = shareButtonRef.current;
-
     if (shareButton) {
       observer.observe(shareButton);
+
+      return () => {
+        // Clean up observer on unmount
+        observer.disconnect();
+      };
     }
 
-    return () => {
-      if (shareButton) {
-        observer.unobserve(shareButton);
-      }
-    };
+    return () => {};
   }, []);
 
   return (