by the way Yigit : is there a debounce function implemented on Enfold ?
on a lot of source codes i read something like this:
win.on( 'debouncedresize', function(){ el_height = $(elements).attr('style',"").filter(':first').height(); set_height(); } );

but i can not find where this is implemented

by the way – you have to use the script to make it easier for you .

If you want to test these settings :
1) the first parameter after a youtube link ( after the ID) has a questionmark ?
2) all following parameters have to be added by a &

so it is : https://www.youtube-nocookie.com/watch?v=YEmI2MDpasE?ecver=2&rel=0

hm – two logos is not so complicated i thought.
see here with a customization of shrinking . – logo in the middle goes with scroll to the left position : https://webers-testseite.de/two-logo-header/
Or here https://webers-testseite.de/cynthia/mille-deco/
because of the other logo experiments on that page it is hard to optimize it for all pages the same time :lol: https://webers-testseite.de/cynthia/logo-move/

hope you will have no performance troubles –
get familiar with debouncing ( resize case) and throttling (scroll case) functions.
but both on the same time – i would not know how to get this.

you see how debounce and throttle work on this page https://css-tricks.com/debouncing-throttling-explained-examples/

i think if that are the results of his page basilis posted then there are no troubles at all

sorry i thought because of a german title that you are natively spoken english.

If you do not find the reason for that – you can add that via quick css, till you find the reason for it.

try this – and see if your troubles are gone – afterwards we can see where the fault is

the easiest way is to use the developer tools of your browser. Nearly all modern browsers got one ( on Safari it has to be activated over the settings dialog of your Safari).
These are very might tools not only to see what class or ID you got on elements. There are javascript environments to test if a script is working.
There are a lot of tutorials on youtube how to use them – not all are good but for the beginning it will give you some infos.

basicly it starts with a right mouse click over the element what you like to examine. Every browser calls it a bit different “inspect element” something like this.
you can see what i do if i like to get the element here on board of your nick “madmanbean”:
left film symbol click and see in fullscreen: https://webers-testseite.de/videos-on-lightbox/

on that right side of those tools you can add css rules or edit them virtually. ( on the video i change font color to red)

see the video on the bottom left : it shows how to test a script virtually on developer tools

thats why i like to see the page.
on source code this will be the easiest way to see that on first view.

to enable gzip there are a lot of options. It depends on your Internet Service Provider what options he allows you to set via php.ini or htaccess.
I often do it via htaccess file on the wordpress root (the htaccess file is a hidden file with a dot on front – so on ftp client you might not see it directly till you enable show hidden files)
there you can set a lot of other options : f.e. browser caching , etag and gzip

on apache servers i add to my htaccess file:

# Secure your wp-config
# Disallow access to important files
<FilesMatch "(^\.|wp-config\.php|xmlrpc\.php|(?<!robots)\.txt|(liesmich|readme)\.*)">
   Require all denied
</FilesMatch>

# secure htaccess-file
<files ~ "^.*\.([Hh][Tt][Aa])">
order allow,deny
deny from all
satisfy all
</files>

# Keep-Alive
<ifModule mod_headers.c>
   Header set Connection keep-alive
</ifModule>
 

# mime types
<IfModule mod_mime.c>
    AddType application/javascript          js
    AddType application/vnd.ms-fontobject   eot
    AddType application/x-font-ttf          ttf ttc
    AddType font/opentype                   otf
    AddType application/x-font-woff         woff
    AddType application/x-woff              woff
    AddType image/svg+xml                   svg svgz 
    AddEncoding gzip                        svgz
</Ifmodule>
 

# GZip Kompression
<IfModule mod_gzip.c>
 mod_gzip_on       Yes
 mod_gzip_dechunk  Yes
 mod_gzip_item_include file      \.(html?|txt|css|js|svg|php|pl)$
 mod_gzip_item_include handler   ^cgi-script$
 mod_gzip_item_include mime      ^text/.*
 mod_gzip_item_include mime      ^application/x-javascript.*
 mod_gzip_item_exclude mime      ^image/.*
 mod_gzip_item_exclude rspheader ^Content-Encoding:.*gzip.*
</IfModule>

 
# Browsercache
<IfModule mod_expires.c>
 ExpiresActive On
 ExpiresDefault "access plus 1 month"
 ExpiresByType text/css "access plus 1 month"
 ExpiresByType text/javascript "access plus 1 month"
 ExpiresByType text/html "access plus 1 month"
 ExpiresByType application/javascript "access plus 1 month"
 ExpiresByType application/x-javascript "access plus 1 month"
 ExpiresByType application/x-font-ttf "access plus 1 month"
 ExpiresByType application/x-font-woff "access plus 1 month"
 ExpiresByType application/x-woff "access plus 1 month"
 ExpiresByType application/xhtml-xml "access plus 600 seconds"
 ExpiresByType image/gif "access plus 1 month"
 ExpiresByType image/jpeg "access plus 1 month"
 ExpiresByType image/svg+xml "access plus 1 year"
 ExpiresByType image/svg "access plus 1 year“
 ExpiresByType image/png "access plus 1 month"
 ExpiresByType image/x-icon "access plus 1 month"
</IfModule>

 
# Deflate by FileType
<IfModule mod_deflate.c>
 AddOutputFilterByType DEFLATE text/plain
 AddOutputFilterByType DEFLATE text/html
 AddOutputFilterByType DEFLATE text/xml
 AddOutputFilterByType DEFLATE text/css
 AddOutputFilterByType DEFLATE text/javascript
 AddOutputFilterByType DEFLATE image/svg+xml
 AddOutputFilterByType DEFLATE application/javascript
 AddOutputFilterByType DEFLATE application/xml
 AddOutputFilterByType DEFLATE application/xhtml+xml
 AddOutputFilterByType DEFLATE application/rss+xml
 AddOutputFilterByType DEFLATE application/atom_xml
 AddOutputFilterByType DEFLATE application/x-woff
 AddOutputFilterByType DEFLATE application/x-font-ttf
 AddOutputFilterByType DEFLATE application/x-font-woff
 AddOutputFilterByType DEFLATE application/javascript
 AddOutputFilterByType DEFLATE application/x-javascript
 AddOutputFilterByType DEFLATE application/x-shockwave-flash
</IfModule>
 
# ETag
Header unset ETag
FileETag None

do this to your functions.php of your child-theme and all links got that addendum:

function add_to_youtube_videos(){
if(is_page(21397)){
?>
<script>
(function($){
	$('.lightbox-added[href*="www.you"]').each(function() {
	   var $this = $(this);       
	   var _href = $this.attr("href"); 
	   $this.attr("href", _href + '?enablejsapi=1&ecver=2&autoplay=1&cc_load_policy=1&playsinline=1&rel=0&showinfo=0&color=white&iv_load_policy=3');
	});  
})(jQuery);
</script>
<?php
}
}
add_action('wp_footer', 'add_to_youtube_videos');

gut – aber denke mal darüber nach ob du nicht diesen Rattenschwanz da immer dran basteln solltest.
Denn wenn du das Video jetzt startest, und dann pausierst, dann siehst Du was ich mit Werbung meine ( das wird mit dem ecver=2 verhindert.) und am ende die related Videos mit dem rel=0 etc. pp.
Ausserdem ist die Nocookie Variante jetzt ohnehin besser wegen der DSGVO ( GDPR )

if you gave the class to the text block than it is at the same div
all classes which are at the same div are not separated by space:

this:

will definitly go to (without spaces on css rules) !
div.avia_textblock.my_custom_class h2
there is on html source a space between (because the dots are gone)

the space comes to the h2 because it is a child of avia_text_block

please show me the link to see something that is not possible

it is hard to help without a link
but first solution was to try get rid of doubled semicolons
second : add rule for firefox and modern browsers – you have all without :

#contactform ::placeholder { 
    color: #fff !important;
    opacity: 1; 
}

the webkit rule seems to be obsolete since Safari 10

this is what is enough for modern browser:

::placeholder { /* Chrome, Firefox, Opera, Safari 10.1+ */
    color: white !important;
    opacity: 1; /* Firefox */
}
:-ms-input-placeholder { /* Internet Explorer 10-11 */
    color: white !important;
}
::-ms-input-placeholder { /* Microsoft Edge */
    color: white !important;
}

this seems to be a good plugin – even the wordpress official sites link to it:
https://de.wordpress.org/plugins/force-strong-passwords/