feat(AIChatPanel): update GradualBlur component to enhance blur effect; adjust ScrollArea scrollbar class handling

src/renderer/components/ai/AIChatPanel.tsx

@@ -204,19 +204,22 @@ export function AIChatPanel({
 
       {/* Scrollable messages area */}
       <div className="relative flex-1 min-h-0">
-        {/* Gradual blur at the top of messages */}
+        {/* Gradual blur at the bottom of messages */}
         {hasMessages && (
           <GradualBlur
-            position="top"
-            strength={2}
-            height="5rem"
-            divCount={6}
+            position="bottom"
+            strength={0.6}
+            height="4rem"
+            divCount={10}
+            curve="ease-out"
+            opacity={0.8}
             zIndex={20}
           />
         )}
         <ScrollArea
           className="h-full"
           viewportRef={messagesContainerRef}
+          scrollbarClassName={hasMessages ? 'z-30' : undefined}
           viewportClassName={
             isHomePage && !hasMessages
               ? '[&>div]:!flex [&>div]:!flex-col [&>div]:!min-h-full [&>div]:!justify-center'
@@ -382,10 +385,9 @@ export function AIChatPanel({
         </ScrollArea>
       </div>
 
-      {/* Fixed input — pinned to the bottom (hidden on initial state) */}
+      {/* Fixed input — pinned to the bottom, above the blur */}
       {hasMessages && (
-        <div className="absolute bottom-0 left-0 right-0 z-10 px-6 pb-5 pt-16 pointer-events-none">
-          <div className="absolute inset-x-0 top-0 h-full bg-gradient-to-b from-transparent via-background/60 to-background/90" />
+        <div className="absolute bottom-0 left-0 right-0 z-30 px-6 pb-5 pt-4 pointer-events-none">
           <div className="relative pointer-events-auto mx-auto max-w-3xl">
             <ChatInput
               input={input}

src/renderer/components/ui/gradual-blur.tsx

@@ -13,6 +13,8 @@ interface GradualBlurProps {
   divCount?: number;
   /** Use exponential progression for stronger end blur */
   exponential?: boolean;
+  /** Distribution curve: linear | ease-out */
+  curve?: 'linear' | 'ease-out';
   /** Opacity applied to each blur layer */
   opacity?: number;
   /** z-index for the overlay */
@@ -30,6 +32,7 @@ export function GradualBlur({
   height = '6rem',
   divCount = 5,
   exponential = false,
+  curve = 'linear',
   opacity = 1,
   zIndex = 10,
   className = '',
@@ -39,14 +42,19 @@ export function GradualBlur({
     const increment = 100 / divCount;
     const direction = getGradientDirection(position);
 
+    const curveFunc = curve === 'ease-out'
+      ? (p: number) => 1 - Math.pow(1 - p, 2)
+      : (p: number) => p;
+
     for (let i = 1; i <= divCount; i++) {
-      const progress = i / divCount;
+      let progress = i / divCount;
+      progress = curveFunc(progress);
 
       let blurValue: number;
       if (exponential) {
         blurValue = Math.pow(2, progress * 4) * 0.0625 * strength;
       } else {
-        blurValue = 0.0625 * (progress * divCount + 1) * strength;
+        blurValue = progress * strength;
       }
 
       const p1 = Math.round((increment * i - increment) * 10) / 10;
@@ -77,7 +85,7 @@ export function GradualBlur({
     }
 
     return divs;
-  }, [position, strength, divCount, exponential, opacity]);
+  }, [position, strength, divCount, exponential, curve, opacity]);
 
   return (
     <div

src/renderer/components/ui/scroll-area.tsx

@@ -8,10 +8,12 @@ function ScrollArea({
   children,
   viewportRef,
   viewportClassName,
+  scrollbarClassName,
   ...props
 }: React.ComponentProps<typeof ScrollAreaPrimitive.Root> & {
   viewportRef?: React.Ref<HTMLDivElement>;
   viewportClassName?: string;
+  scrollbarClassName?: string;
 }) {
   return (
     <ScrollAreaPrimitive.Root
@@ -29,7 +31,7 @@ function ScrollArea({
       >
         {children}
       </ScrollAreaPrimitive.Viewport>
-      <ScrollBar />
+      <ScrollBar className={scrollbarClassName} />
       <ScrollAreaPrimitive.Corner />
     </ScrollAreaPrimitive.Root>
   )
@@ -45,7 +47,7 @@ function ScrollBar({
       data-slot="scroll-area-scrollbar"
       orientation={orientation}
       className={cn(
-        "flex touch-none p-px transition-colors select-none",
+        "flex touch-none p-px transition-colors select-none z-50",
         orientation === "vertical" &&
           "h-full w-2.5 border-l border-l-transparent",
         orientation === "horizontal" &&