修复：主界面下拉出现两个重复的回到页面顶部按钮。注释了NavBar.tsx中的按钮，保留并修改了scrollToTop.tsx中的按钮样式。

src/components/Navbar.tsx

@@ -464,7 +464,7 @@ export default function Navbar() {
       </motion.nav>
 
       {/* 返回顶部按钮 */}
-      <AnimatePresence>
+      {/* <AnimatePresence>
         {showScrollTop && (
           <motion.button
             initial={{ opacity: 0, scale: 0.8, y: 20 }}
@@ -485,7 +485,7 @@ export default function Navbar() {
             </motion.div>
           </motion.button>
         )}
-      </AnimatePresence>
+      </AnimatePresence> */}
     </>
   );
 }

src/components/ScrollToTop.tsx

@@ -41,7 +41,7 @@ export default function ScrollToTop() {
           exit={{ opacity: 0, scale: 0.8, y: 20 }}
           transition={{ duration: 0.2, ease: 'easeOut' }}
           onClick={scrollToTop}
-          className="fixed bottom-6 right-6 w-12 h-12 bg-gradient-to-br from-orange-500 to-orange-600 hover:from-orange-600 hover:to-orange-700 text-white rounded-full shadow-lg hover:shadow-xl transition-all duration-200 flex items-center justify-center z-40 group"
+          className="fixed bottom-6 right-6 w-12 h-12 bg-gradient-to-br from-orange-400/70 to-amber-300/70 hover:from-orange-600/70 hover:to-orange-700/70 text-white rounded-full shadow-lg hover:shadow-xl transition-all duration-200 flex items-center justify-center z-40 group"
           whileHover={{ scale: 1.1, y: -2 }}
           whileTap={{ scale: 0.9 }}
         >