Switch scroll reference

Use client instead of offset sizes to exclude scrollbar in calculating
scroll amounts.

src/pages/index.tsx

@@ -322,11 +322,11 @@ const IndexPage: NextPage = () => {
 
     scrollRef.current = true;
     const target = e.currentTarget
-    if (target.scrollHeight > target.offsetHeight) {
-      worldScrollRef.current.scrollTop = Math.floor(target.scrollTop / (target.scrollHeight - target.offsetHeight) * (worldScrollRef.current.scrollHeight - worldScrollRef.current.offsetHeight));
+    if (target.scrollHeight > target.clientHeight) {
+      worldScrollRef.current.scrollTop = Math.floor(target.scrollTop / (target.scrollHeight - target.clientHeight) * (worldScrollRef.current.scrollHeight - worldScrollRef.current.clientHeight));
     }
-    if (target.scrollWidth > target.offsetWidth) {
-      worldScrollRef.current.scrollLeft = Math.floor(target.scrollLeft / (target.scrollWidth - target.offsetWidth) * (worldScrollRef.current.scrollWidth - worldScrollRef.current.offsetWidth));
+    if (target.scrollWidth > target.clientWidth) {
+      worldScrollRef.current.scrollLeft = Math.floor(target.scrollLeft / (target.scrollWidth - target.clientWidth) * (worldScrollRef.current.scrollWidth - worldScrollRef.current.clientWidth));
     }
   }
 
@@ -342,11 +342,11 @@ const IndexPage: NextPage = () => {
 
     scrollRef.current = true;
     const target = e.currentTarget
-    if (target.scrollHeight > target.offsetHeight) {
-      baseMapScrollRef.current.scrollTop = Math.floor(target.scrollTop / (target.scrollHeight - target.offsetHeight) * (baseMapScrollRef.current.scrollHeight - baseMapScrollRef.current.offsetHeight));
+    if (target.scrollHeight > target.clientHeight) {
+      baseMapScrollRef.current.scrollTop = Math.floor(target.scrollTop / (target.scrollHeight - target.clientHeight) * (baseMapScrollRef.current.scrollHeight - baseMapScrollRef.current.clientHeight));
     }
-    if (target.scrollWidth > target.offsetWidth) {
-      baseMapScrollRef.current.scrollLeft = Math.floor(target.scrollLeft / (target.scrollWidth - target.offsetWidth) * (baseMapScrollRef.current.scrollWidth - baseMapScrollRef.current.offsetWidth));
+    if (target.scrollWidth > target.clientWidth) {
+      baseMapScrollRef.current.scrollLeft = Math.floor(target.scrollLeft / (target.scrollWidth - target.clientWidth) * (baseMapScrollRef.current.scrollWidth - baseMapScrollRef.current.clientWidth));
     }
   }