refactor: 移除hero水墨动画，优化全局样式与组件细节

src/components/ui/back-to-top.tsx

@@ -35,7 +35,7 @@ export function BackToTop() {
           exit={shouldReduceMotion ? {} : { opacity: 0, y: 20, scale: 0.8 }}
           transition={{ duration: 0.2, ease: 'easeOut' }}
           onClick={scrollToTop}
-          className="fixed bottom-8 right-8 z-50 p-3 bg-[#C41E3A] text-white rounded-full shadow-lg hover:bg-[#A01830] hover:shadow-xl transition-all duration-200 focus:outline-none focus:ring-2 focus:ring-[#C41E3A] focus:ring-offset-2"
+          className="fixed right-4 bottom-20 md:bottom-8 md:right-8 z-40 p-3 bg-[#C41E3A] text-white rounded-full shadow-lg hover:bg-[#A01830] hover:shadow-xl transition-all duration-200 focus:outline-none focus:ring-2 focus:ring-[#C41E3A] focus:ring-offset-2"
           aria-label="返回顶部"
           title="返回顶部"
           style={{

src/components/ui/flip-clock.tsx

@@ -1,6 +1,6 @@
 'use client';
 
-import { useReducer } from 'react';
+import { useReducer, useEffect } from 'react';
 import { motion, AnimatePresence } from 'framer-motion';
 
 interface FlipCardProps {
@@ -93,7 +93,9 @@ function FlipCard({ value, label, maxDigits = 2 }: FlipCardProps) {
     },
     { current: value, previous: value }
   );
-  dispatch(value);
+  useEffect(() => {
+    dispatch(value);
+  }, [value]);
 
   const formatNumber = (num: number) => {
     const str = num.toString().padStart(maxDigits, '0');