perf: 返回按钮的图标可以有阴影

src/components/BtnBack.vue

@@ -3,7 +3,7 @@
     <button>
       <img
         class=""
-        :src="require(`@/assets/images/icon_back_${props.color}.png`)"
+        :src="require(`@/assets/images/icon_back_${props.color}${textShadow ? '-with-shadow' : ''}.png`)"
         alt=""
         draggable="false"
       >
@@ -84,7 +84,7 @@ const textColor = computed(() => {
     line-height: calc(28px / v-bind('windowHeightDesign') * v-bind('windowHeight'));
   }
   >.text.needShadow{
-    text-shadow: calc(1px / v-bind('windowHeightDesign') * v-bind('windowHeight')) calc(1px / v-bind('windowHeightDesign') * v-bind('windowHeight')) calc(2px / v-bind('windowHeightDesign') * v-bind('windowHeight')) rgba(0, 0, 0, 0.3);
+    text-shadow: calc(1px / v-bind('windowHeightDesign') * v-bind('windowHeight')) calc(1px / v-bind('windowHeightDesign') * v-bind('windowHeight')) calc(2px / v-bind('windowHeightDesign') * v-bind('windowHeight')) rgba(0, 0, 0, 0.7);
   }
 }
 </style>