界面语言切换功能，修复nav异常

templates/main.html

@@ -1,5 +1,5 @@
 {% set no_path_section = true %}
-{% set page_name = "domain_main" %}
+{% set page_name = "homepage" %}
 {% extends "layout/basic.html" %}
 {% import "components/contest.html" as contest with context %}
 {% block content %}