refactor(placeholder): extract tile sprite strip

web/src/components/Placeholder/TileSpriteStrip.tsx

@@ -0,0 +1,67 @@
+import { cn } from "@/lib/utils";
+import type { TileSprite } from "./tileSprites";
+
+interface TileSpriteStripProps {
+  sprite: TileSprite;
+  scale?: number;
+  className?: string;
+  testId?: string;
+}
+
+const DEFAULT_SCALE = 2;
+
+const getAnimationName = (sprite: TileSprite, scale: number) => `tile-sprite-${sprite.name}-${scale}x`;
+
+const TileSpriteStrip = ({ sprite, scale = DEFAULT_SCALE, className, testId }: TileSpriteStripProps) => {
+  const stripWidth = sprite.frameWidth * sprite.frames;
+  const displayStripWidth = stripWidth * scale;
+  const displayStripHeight = sprite.frameHeight * scale;
+  const displayFrameWidth = sprite.frameWidth * scale;
+  const animationName = getAnimationName(sprite, scale);
+
+  return (
+    <>
+      <style>{`
+        @keyframes ${animationName} {
+          from { transform: translateX(0); }
+          to { transform: translateX(-${displayStripWidth}px); }
+        }
+
+        @media (prefers-reduced-motion: reduce) {
+          [data-tile-sprite-strip="${animationName}"] {
+            animation: none !important;
+            transform: translateX(0) !important;
+          }
+        }
+      `}</style>
+      <div
+        aria-hidden="true"
+        data-testid={testId}
+        className={cn("relative shrink-0 overflow-hidden", className)}
+        style={{ width: displayFrameWidth, height: displayStripHeight, overflow: "hidden" }}
+      >
+        <img
+          data-tile-sprite-strip={animationName}
+          src={sprite.src}
+          alt=""
+          width={stripWidth}
+          height={sprite.frameHeight}
+          draggable={false}
+          style={{
+            display: "block",
+            width: displayStripWidth,
+            height: displayStripHeight,
+            maxWidth: "none",
+            imageRendering: "pixelated",
+            animationName,
+            animationDuration: `${sprite.duration}ms`,
+            animationTimingFunction: `steps(${sprite.frames})`,
+            animationIterationCount: "infinite",
+          }}
+        />
+      </div>
+    </>
+  );
+};
+
+export default TileSpriteStrip;

web/src/components/Placeholder/index.tsx

@@ -1,6 +1,7 @@
 import { type ReactNode, useState } from "react";
 import { cn } from "@/lib/utils";
 import { DEFAULT_MESSAGES, type PlaceholderVariant } from "./messages";
+import TileSpriteStrip from "./TileSpriteStrip";
 import { pickTileSprite } from "./tileSprites";
 
 interface PlaceholderProps {
@@ -10,17 +11,12 @@ interface PlaceholderProps {
   className?: string;
 }
 
-const TILE_SIZE = 32;
 const DISPLAY_SCALE = 2;
-const DISPLAY_SIZE = TILE_SIZE * DISPLAY_SCALE;
 
 const Placeholder = ({ variant, message, children, className }: PlaceholderProps) => {
   const [sprite] = useState(pickTileSprite);
   const resolvedMessage = message ?? DEFAULT_MESSAGES[variant];
   const isLoading = variant === "loading";
-  const stripWidth = sprite.frameWidth * sprite.frames;
-  const displayStripWidth = stripWidth * DISPLAY_SCALE;
-  const displayStripHeight = sprite.frameHeight * DISPLAY_SCALE;
 
   return (
     <div
@@ -28,45 +24,7 @@ const Placeholder = ({ variant, message, children, className }: PlaceholderProps
       aria-live={isLoading ? "polite" : undefined}
       className={cn("flex flex-col items-center justify-center max-w-md mx-auto px-4 py-8", className)}
     >
-      <style>{`
-        @keyframes placeholder-tile-strip {
-          from { transform: translateX(0); }
-          to { transform: translateX(-${displayStripWidth}px); }
-        }
-
-        @media (prefers-reduced-motion: reduce) {
-          [data-placeholder-strip] {
-            animation: none !important;
-            transform: translateX(0) !important;
-          }
-        }
-      `}</style>
-      <div
-        aria-hidden="true"
-        data-testid="placeholder-sprite"
-        className="relative shrink-0"
-        style={{ width: DISPLAY_SIZE, height: DISPLAY_SIZE, overflow: "hidden" }}
-      >
-        <img
-          data-placeholder-strip=""
-          src={sprite.src}
-          alt=""
-          width={stripWidth}
-          height={sprite.frameHeight}
-          draggable={false}
-          style={{
-            display: "block",
-            width: displayStripWidth,
-            height: displayStripHeight,
-            maxWidth: "none",
-            imageRendering: "pixelated",
-            animationName: "placeholder-tile-strip",
-            animationDuration: `${sprite.duration}ms`,
-            animationTimingFunction: `steps(${sprite.frames})`,
-            animationIterationCount: "infinite",
-          }}
-        />
-      </div>
+      <TileSpriteStrip sprite={sprite} scale={DISPLAY_SCALE} className="relative shrink-0" testId="placeholder-sprite" />
       <p className="mt-3 font-mono text-sm text-muted-foreground">{resolvedMessage}</p>
       {children && <div className="mt-4">{children}</div>}
     </div>

web/src/pages/About.tsx

@@ -1,4 +1,5 @@
 import { ExternalLinkIcon } from "lucide-react";
+import TileSpriteStrip from "@/components/Placeholder/TileSpriteStrip";
 import { TILE_SPRITES, type TileSprite } from "@/components/Placeholder/tileSprites";
 import SettingGroup from "@/components/Settings/SettingGroup";
 import SettingSection from "@/components/Settings/SettingSection";
@@ -14,82 +15,12 @@ const PRODUCT_LINKS = [
 
 const PRODUCT_POINTS = ["Open. Write. Done.", "Markdown-native.", "Fully yours."];
 
-const BIRD_META: Record<TileSprite["name"], { label: string; description: string }> = {
-  OwlBlink: {
-    label: "Owl",
-    description: "Night watch idle with a compact blink.",
-  },
-  EagleIdle: {
-    label: "Eagle",
-    description: "Perched idle with a sharp head and steady chest motion.",
-  },
-  ToucanIdle: {
-    label: "Toucan",
-    description: "Calm tropical idle built around a large curved beak.",
-  },
-};
-
-const getBirdAnimationName = (sprite: TileSprite) => `about-bird-${sprite.name}`;
-
-const BIRD_KEYFRAMES_CSS = `
-  ${TILE_SPRITES.map(
-    (sprite) => `
-      @keyframes ${getBirdAnimationName(sprite)} {
-        from { transform: translateX(0); }
-        to { transform: translateX(-${sprite.frameWidth * sprite.frames * SPRITE_SCALE}px); }
-      }
-    `,
-  ).join("\n")}
-
-  @media (prefers-reduced-motion: reduce) {
-    .about-bird-strip {
-      animation: none !important;
-      transform: translateX(0) !important;
-    }
-  }
-`;
-
 const BirdSprite = ({ sprite }: { sprite: TileSprite }) => {
-  const stripWidth = sprite.frameWidth * sprite.frames;
-  const displayWidth = stripWidth * SPRITE_SCALE;
-  const displayHeight = sprite.frameHeight * SPRITE_SCALE;
-  const frameDisplayWidth = displayWidth / sprite.frames;
-  const meta = BIRD_META[sprite.name];
-
   return (
-    <figure className="flex min-w-0 flex-1 basis-36 flex-col items-center gap-3 rounded-xl border border-border bg-muted/20 px-4 py-4 text-center">
-      <div
-        aria-hidden="true"
-        data-testid="about-bird-sprite"
-        className="relative size-16 shrink-0 overflow-hidden"
-        style={{ width: frameDisplayWidth, height: displayHeight }}
-      >
-        <img
-          className="about-bird-strip"
-          src={sprite.src}
-          alt=""
-          width={stripWidth}
-          height={sprite.frameHeight}
-          draggable={false}
-          style={{
-            display: "block",
-            width: displayWidth,
-            height: displayHeight,
-            maxWidth: "none",
-            imageRendering: "pixelated",
-            animationName: getBirdAnimationName(sprite),
-            animationDuration: `${sprite.duration}ms`,
-            animationTimingFunction: `steps(${sprite.frames})`,
-            animationIterationCount: "infinite",
-          }}
-        />
-      </div>
+    <figure className="flex w-auto min-w-28 flex-none flex-col items-center gap-3 rounded-xl border border-border bg-muted/20 px-4 py-4 text-center">
+      <TileSpriteStrip sprite={sprite} scale={SPRITE_SCALE} className="size-16" testId="about-bird-sprite" />
       <figcaption className="min-w-0">
-        <div className="flex flex-col items-center gap-1">
-          <h3 className="font-mono text-sm font-semibold text-foreground">{sprite.name}</h3>
-          <span className="font-mono text-[11px] uppercase tracking-wider text-muted-foreground">{meta.label}</span>
-        </div>
-        <p className="mt-2 text-xs leading-5 text-muted-foreground">{meta.description}</p>
+        <h3 className="font-mono text-sm text-foreground">{sprite.name}</h3>
       </figcaption>
     </figure>
   );
@@ -98,8 +29,6 @@ const BirdSprite = ({ sprite }: { sprite: TileSprite }) => {
 const About = () => {
   return (
     <section className="mx-auto w-full max-w-5xl min-h-full flex flex-col justify-start items-start sm:pt-3 md:pt-6 pb-8">
-      <style>{BIRD_KEYFRAMES_CSS}</style>
-
       <div className="w-full px-4 sm:px-6">
         <div className="w-full rounded-xl border border-border bg-background px-4 py-4 text-muted-foreground">
           <SettingSection