Add entry fade-in and animated gradient header

src/App.jsx

@@ -187,7 +187,7 @@ function App() {
   }, [handleGlobalDragEnter, handleGlobalDragOver, handleGlobalDragLeave, handleGlobalDrop]);
 
   return (
-    <div className="min-h-screen bg-gradient-to-br from-blue-50 to-indigo-100 relative">
+    <div className="min-h-screen bg-gradient-to-br from-blue-50 to-indigo-100 relative page-fade-in">
       {/* 全页面拖拽覆盖层 */}
       {globalDragOver && (
         <div
@@ -263,7 +263,7 @@ function App() {
                     <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M9 19v-6a2 2 0 00-2-2H5a2 2 0 00-2 2v6a2 2 0 002 2h2a2 2 0 002-2zm0 0V9a2 2 0 012-2h2a2 2 0 012 2v10m-6 0a2 2 0 002 2h2a2 2 0 002-2m0 0V5a2 2 0 012-2h2a2 2 0 012 2v14a2 2 0 01-2 2h-2a2 2 0 01-2-2z" />
                   </svg>
                 </div>
-                <h1 className="text-lg font-bold text-gray-800">
+                <h1 className="text-lg font-extrabold text-transparent bg-clip-text bg-gradient-to-r from-blue-600 via-purple-500 to-indigo-600 animate-gradient-slow">
                   Log Analyzer
                 </h1>
                 <button

src/index.css

@@ -224,3 +224,46 @@ input[type="checkbox"]:focus {
     animation: none !important;
   }
 }
+
+/* 页面入场动画 */
+@keyframes pageFadeIn {
+  from {
+    opacity: 0;
+    transform: translateY(10px);
+  }
+  to {
+    opacity: 1;
+    transform: translateY(0);
+  }
+}
+
+.page-fade-in {
+  animation: pageFadeIn 0.5s ease-out;
+}
+
+@media (prefers-reduced-motion: reduce) {
+  .page-fade-in {
+    animation: none !important;
+  }
+}
+
+/* 渐变文字动画 */
+@keyframes gradientShift {
+  0%, 100% {
+    background-position: 0% 50%;
+  }
+  50% {
+    background-position: 100% 50%;
+  }
+}
+
+.animate-gradient-slow {
+  background-size: 200% 200%;
+  animation: gradientShift 8s ease infinite;
+}
+
+@media (prefers-reduced-motion: reduce) {
+  .animate-gradient-slow {
+    animation: none !important;
+  }
+}