混合内容页：请求不安全的样式表错误

我有一个网站在工作。当我打开任何使用 http:// 协议的页面时，所有内容都已正确加载，但是当我尝试使用https协议加载页面时，页面已加载但没有css和javascript文件。
控制台显示以下错误。

混合内容：位于“https://www.example.com/index.php?main_page=login”的页面是通过HTTPS加载的，但请求了不安全的样式表“http://www.example.com/site_map.html”。此请求已被阻止;内容必须通过 HTTPS 提供。

我认为问题是浏览器在通过https协议请求时无法加载任何css文件。
问题是htaccess文件，因为当我删除它时，css文件正确加载。

加载到浏览器的页面和css文件在其URL中带有https，如下所示

<link rel="stylesheet" type="text/css" href="https://www.example.com/includes/templates/classic/css/style1.css">
<link rel="stylesheet" type="text/css" href="https://www.example.com/includes/templates/classic/css/style2.css">

当浏览器尝试加载css文件时，它被重定向到

http://www.example.com/site_map.html  

我如何使htaccess允许https打开特定文件夹中的css和js文件？

谢谢

更新htaccess 文件内容

RewriteEngine On
RewriteCond %{SERVER_PORT} ^443$
RewriteRule (.*) http://www.example.com/$1 
###############################################################################
# Common directives
###############################################################################
# NOTE: Replace /shop/ with the relative web path of your catalog in the "Rewrite Base" line below:

Options +FollowSymLinks
RewriteEngine on

RewriteCond %{HTTP_HOST} ^example\.com$ [NC]
RewriteRule ^(.*)$ http://www.example.com/$1 [R=301,L]

RewriteCond %{THE_REQUEST} ^[A-Z]{3,9}\ /index\.php\ HTTP/
RewriteRule ^index\.php$ http://www.example.com/ [R=301,L]

#RewriteBase /

###############################################################################
# Start Ultimate SEO URLs
###############################################################################

# Original (unchanged) URL formats
RewriteRule ^(.*)-p-([0-9]+)(.*)$ index\.php?main_page=product_info&products_id=$2&%{QUERY_STRING} [L]
RewriteRule ^(.*)-c-(.*)-p(.*)\.html$ /index.php?main_page=$4&cPath=$2&sort=$5&page=$3
RewriteRule ^(.*)-c-([0-9_]+)(.*)$ index\.php?main_page=index&cPath=$2&%{QUERY_STRING} [L]
RewriteRule ^(.*)-ez-(.*).html$ index.php?main_page=page&id=$2 [L]

# All other pages
# Don't rewrite real files or directories
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^(.*)$ index\.php?main_page=$1&%{QUERY_STRING} [L]


# Block out any script trying to base64_encode data within the URL.
RewriteCond %{QUERY_STRING} base64_encode[^(]*\([^)]*\) [OR]
# Block out any script that includes a <script> tag in URL.
RewriteCond %{QUERY_STRING} (<|%3C)([^s]*s)+cript.*(>|%3E) [NC,OR]
# Block out any script trying to set a PHP GLOBALS variable via URL.
RewriteCond %{QUERY_STRING} GLOBALS(=|\[|\%[0-9A-Z]{0,2}) [OR]
# Block out any script trying to modify a _REQUEST variable via URL.
RewriteCond %{QUERY_STRING} _REQUEST(=|\[|\%[0-9A-Z]{0,2})
RewriteRule   index.html$  index.php [QSA] 


# 480 weeks
<FilesMatch "\.(ico|pdf|flv|jpg|jpeg|png|gif|js|css|swf)$">
Header set Cache-Control "max-age=290304000, public"
</FilesMatch>

# 2 DAYS
<FilesMatch "\.(xml|txt)$">
Header set Cache-Control "max-age=172800, public, must-revalidate"
</FilesMatch>

# 2 HOURS
<FilesMatch "\.(html|htm)$">
Header set Cache-Control "max-age=7200, must-revalidate"
</FilesMatch>
# compress text, html, javascript, css, xml:
AddOutputFilterByType DEFLATE text/plain
AddOutputFilterByType DEFLATE text/html
AddOutputFilterByType DEFLATE text/xml
AddOutputFilterByType DEFLATE text/css
AddOutputFilterByType DEFLATE application/xml
AddOutputFilterByType DEFLATE application/xhtml+xml
AddOutputFilterByType DEFLATE application/rss+xml
AddOutputFilterByType DEFLATE application/javascript
AddOutputFilterByType DEFLATE application/x-javascript

RewriteEngine on
RewriteBase /

ErrorDocument 404 /index.php
RewriteRule   index.html$  index.php [QSA]