fix: remove all unnecessary animations from all pages

- Remove dead code animations (animate-in, fade-in, slide-in, zoom-in, shake) from tailwindcss-animate plugin (not installed)
- Remove decorative transition effects (transition-all, transition-colors) from all page components
- Remove scale effects (active:scale-95) from buttons
- Remove bounce animations (animate-bounce) from icons
- Keep functional animate-spin on loading spinners as they provide essential loading feedback

Affected pages: Dashboard, Timestamp, Jwt, JsonTools, Base64Converter, HtmlToMarkdown, MarkdownToHtml, QrCode, TextStatistics

pages/Timestamp/LiveClock.tsx

@@ -80,7 +80,7 @@ const LiveClock = React.memo(({ unit, onUseNow, className, ...props }: LiveClock
         type="button"
         onClick={handleUseNow}
         title={t('timestamp:useNowTooltip')}
-        className="flex h-7 w-7 items-center justify-center rounded-md border border-input bg-background text-muted-foreground shadow-sm transition-all hover:bg-accent hover:text-foreground active:scale-95 focus-visible:outline-none focus-visible:ring-1 focus-visible:ring-ring"
+        className="flex h-7 w-7 items-center justify-center rounded-md border border-input bg-background text-muted-foreground shadow-sm hover:bg-accent hover:text-foreground focus-visible:outline-none focus-visible:ring-1 focus-visible:ring-ring"
       >
         <Clock className="w-3.5 h-3.5" />
       </button>

pages/Timestamp/ResultView.tsx

@@ -50,7 +50,7 @@ const ResultView = React.memo(
       return (
         <div
           className={cn(
-            'flex-1 flex items-center justify-center text-sm font-medium border border-dashed border-border/60 rounded-xl py-12 px-4 text-center text-muted-foreground bg-muted/20 min-h-[320px] animate-in fade-in duration-200',
+            'flex-1 flex items-center justify-center text-sm font-medium border border-dashed border-border/60 rounded-xl py-12 px-4 text-center text-muted-foreground bg-muted/20 min-h-[320px]',
             className,
           )}
           {...props}
@@ -61,13 +61,7 @@ const ResultView = React.memo(
     }
 
     return (
-      <div
-        className={cn(
-          'animate-in fade-in slide-in-from-bottom-2 duration-300 flex flex-col w-full',
-          className,
-        )}
-        {...props}
-      >
+      <div className={cn('flex flex-col w-full', className)} {...props}>
         {/* 顶部小标签 */}
         <span className="block text-muted-foreground/90 mb-2.5 text-xs font-semibold tracking-wider uppercase">
           {t('timestamp:resultLabel')}
@@ -78,7 +72,7 @@ const ResultView = React.memo(
           对齐 shadcn 官方卡片风格，使用 bg-card、border-border 构筑多层级阴影。
           核心数值直接拉粗为 text-foreground (在黑夜模式下会自动转为大气的纯白，完美避开刺眼强光)
         */}
-        <div className="bg-card text-card-foreground border border-border p-4 sm:p-5 rounded-xl relative mb-3.5 shadow-sm flex justify-between items-center gap-4 focus-within:ring-1 focus-within:ring-ring transition-all">
+        <div className="bg-card text-card-foreground border border-border p-4 sm:p-5 rounded-xl relative mb-3.5 shadow-sm flex justify-between items-center gap-4 focus-within:ring-1 focus-within:ring-ring">
           <span className="font-mono font-extrabold text-foreground break-all text-xl sm:text-2xl tracking-tight leading-tight select-all tabular-nums">
             {result}
           </span>

pages/Timestamp/index.tsx

@@ -70,17 +70,13 @@ export default function Index() {
                   value={input}
                   onChange={(e: { target: { value: string } }) => setInput(e.target.value)}
                   className={cn(
-                    'font-mono font-semibold h-10 shadow-sm placeholder:text-muted-foreground/60 focus:bg-background transition-all',
+                    'font-mono font-semibold h-10 shadow-sm placeholder:text-muted-foreground/60 focus:bg-background',
                     error && 'border-destructive focus-visible:ring-destructive',
                   )}
                 />
 
                 {/* 错误自愈提示 */}
-                {error && (
-                  <p className="text-destructive text-xs font-medium px-0.5 animate-in fade-in slide-in-from-top-1 duration-150">
-                    {error}
-                  </p>
-                )}
+                {error && <p className="text-destructive text-xs font-medium px-0.5">{error}</p>}
               </div>
 
               {/* 核心配置群：单位切换 + 时区选择紧凑横排 */}