feat: 修改

src/page-instrument/header-top/index.tsx

@@ -462,8 +462,8 @@ export default defineComponent({
     });
     /** 模式切换按钮 */
     const toggleBtn = computed(() => {
-      // 乐教通不限
-      if (query["isYjt"] == "1") return { display: false, disabled: false };
+      // 乐教通不限和后台预览
+      if (query["isYjt"] == "1" || state.systemType === 'web') return { display: false, disabled: false };
       // 老师端，打击乐&节奏练习不显示
       if (state.isPercussion && state.platform === IPlatform.PC) return { display: false, disabled: false };
       if(state.isCombineRender) return { display: false, disabled: false };