[simple] Editing theme files in WP doesn’t change, only if I upload to FTP

So there is no “You need to make this file writable before you can save your changes. See the Codex for more information.” below the editbox?

And indeed, at https://www.ineve.com there is nothing from WP so changes won’t show there.
No mixup with a double installation or a double set of tables?

Thanks henkholland but nope, everything is writable, that’s for sure.. no errors (I installed WP using Installatron).

I know you guys just see the under constructions design, but when I enter https://www.inveve.com I actually can see my blog after I’ve logged into WordPress.

I think it comes down to this: Where can I see/change the link that WordPress uses to get the files at Appereance->Edit ?

You apparently installed in the root, because this brings me the login screen:
https://www.inveve.com/wp-login.php

but there is an index.html of index.htm in the root also that goes first, so rename that to indexold.html and make sure there is an index.php in your root with this:

<?php
/**
 * Front to the WordPress application. This file doesn't do anything, but loads
 * wp-blog-header.php which does and tells WordPress to load the theme.
 *
 * @package WordPress
 */

/**
 * Tells WordPress to load the WordPress theme and output it.
 *
 * @var bool
 */
define('WP_USE_THEMES', true);

/** Loads the WordPress Environment and Template */
require('./wordpress/wp-blog-header.php');
?>

only then I can see your WordPress site and then we can dig into the css question.

Henkholland. First thank you for your time and support. But I’ve hided the real wordpress site on purpose, because it isn’t finished yet, and thus; not ready for public. But thanks anyway.