v2.301 - Fix Slide Selector 2

Author: imjustinliao

frontend/src/components/app/AppContentRouter.tsx

@@ -233,13 +233,16 @@ export function AppContentRouter() {
       }
     }
     const newParams = new URLSearchParams(searchParams.toString())
-    newParams.delete("q")
     newParams.delete("view")
+    if (!q) newParams.delete("q")
     const qs = newParams.toString()
     router.replace(qs ? `/app?${qs}` : "/app", { scroll: false })
   }, [searchParams, router, setActiveView])
 
-  const clearInitialPrompt = useCallback(() => setInitialPrompt(null), [])
+  const clearInitialPrompt = useCallback(() => {
+    setInitialPrompt(null)
+    router.replace("/app", { scroll: false })
+  }, [router])
   const [resetKey, setResetKey] = useState(0)
   const [demoSessions, setDemoSessions] = useState<Record<string, Session>>({})
 
@@ -266,10 +269,10 @@ export function AppContentRouter() {
   }, [searchParams, router, upsertConversation, setActiveView])
 
   useEffect(() => {
-    if (activeView === "new") {
+    if (activeView === "new" && !initialPrompt) {
       queueMicrotask(() => setResetKey((k) => k + 1))
     }
-  }, [activeView])
+  }, [activeView, initialPrompt])
 
   const handleSessionComplete = useCallback((session: Session) => {
     setDemoSessions((prev) => ({ ...prev, [session.id]: session }))

frontend/src/components/blocks/TextbookRenderer.tsx

@@ -290,11 +290,11 @@ export const SessionFloatingTOC = React.memo(function SessionFloatingTOC(props:
                 }
             }
 
-            /* Active = last entry whose heading is at or above the viewport reference point.
-               Each entry "owns" the range from its heading down to the next entry's heading.
-               Reference = viewport top + small offset so once a heading scrolls past the
-               top area the indicator switches to it. */
-            const refPoint = container.scrollTop + 100
+            /* ChatGPT-style: active = last heading that scrolled past the top area.
+               Each entry owns the range from its heading to the next heading.
+               Offset 30 ≈ scroll-to margin (24px) + 6px buffer — keeps click-to-scroll
+               and manual scroll tracking perfectly in sync, even for short sections. */
+            const refPoint = container.scrollTop + 30
             let activeIdx = 0
             for (let i = positions.length - 1; i >= 0; i--) {
                 if (refPoint >= positions[i]) {