Fix: 修正导航栏动画 & 移除无用代码

src/layouts/CalculatorLayout.vue

@@ -350,20 +350,12 @@
     return availableLanguages.findIndex(lang => lang.code === locale.value)
   })
 
-  function changeLanguage (langCode: string) {
-    locale.value = langCode
-  }
-
   function handleLanguageChange (index: number) {
     if (index !== undefined && index >= 0 && index < availableLanguages.length) {
       locale.value = availableLanguages[index].code
     }
   }
 
-  function toggleLanguage () {
-    locale.value = locale.value === 'zh' ? 'en' : 'zh'
-  }
-
   function handleSelect (_index: number) {
     drawer.value = false // 选择后自动关闭抽屉
   }
@@ -451,11 +443,6 @@
   }
 }
 
-/* 抽屉内容的紧凑布局 */
-.drawer-transition {
-  transition: width 0.3s ease;
-}
-
 /* 移动设备上的特殊处理 */
 @media (max-width: 599px) {
   .v-list-item.pa-4 {