维护页面，无需重定向到错误页面

I have to make a maintenance page for my website with the htaccess, I've searched on the internet and could only find snippets/scripts which redirect but I only want that it displays a message on the page itself for people, but not for a specified ip-adres. So when I enable the script in the htaccess it has to show a message on every page/ file(=css, etc.) except for my ip-adresI have to make a maintenance page for my websit