feat: 在 App.vue 组件中添加装饰性背景元素，包括花朵、云朵和彩虹光晕，优化背景样式和动画效果，同时调整 ParticleBackground 组件的粒子数量和样式以提升视觉效果。

src/components/ParticleBackground.vue

@@ -12,17 +12,18 @@ const breakpoints = useBreakpoints({
 })
 
 const isMobile = breakpoints.smaller('tablet')
-const particleCount = isMobile.value ? 800 : 1500
+const particleCount = isMobile.value ? 1000 : 1800
 
 // 动画参数
 const config = {
-  particleSize: 1.5,
+  particleSize: 2,
   systemRadius: 15,
-  baseSpeed: 0.2,
+  baseSpeed: 0.15,
   hoverRadius: 3,
-  color: 0x7ac5e8,
-  lineColor: 0x5ab0d6,
-  lineDistance: 2.5
+  color: 0xb4e0f7,
+  lineColor: 0xa8d8ea,
+  lineDistance: 3,
+  particleCount: isMobile.value ? 1000 : 1800
 }
 
 let scene, camera, renderer, particles, lines, mouse = { x: 0, y: 0 }
@@ -220,14 +221,15 @@ onUnmounted(() => {
   height: 100%;
   z-index: var(--z-index-particle);
   pointer-events: none;
-  opacity: 0.6;
+  opacity: 0.4;
+  mix-blend-mode: screen;
   transition: opacity 0.3s ease;
 }
 
-/* 移动设备降低不透明度 */
+/* 移动设备优化 */
 @media (max-width: 768px) {
   .particle-canvas {
-    opacity: 0.3;
+    opacity: 0.2;
   }
 }