I want to make a new Page on a Website with my own HTML/CSS content. We got a HTML page from a designer, with content in it. I want to implement this into a normal subpage on a website. All content on the top and left side should remain the same. Only the content on this specific page should be edited.
I tried to take a content editor web part and inserted my HTML, but Sharepoint is always reformating the whole HTML and makes it useless in this way.
What would be best practice to do this?