hover effect ist jetzt ein wenig too much – oder .
ist halt doppelt gemoppelt.

Aber es klappt. Bis dann
PS : ich bin kein Geheimniskrämer – unter meinem Avatar verbirgt sich meine Internetseite – respektive meine Kontaktdaten.

if you want to give more than one custom class to an ALB Element just insert the two classnames behind each other with a space between:

f.e.: plp-iconbox clickable

btw: on former Enfold Times this was nice for columns too! – but now Column ALB Element has an input field for link to have the whole column clickable

if you like to have the controls you can delete this parameter from the code-block element code
&controls=0

maybe instead add the &playsinline=1 parameter – this is for the ipad / iphone background option.

@Mike : seems to be all 16/9 videos – must be something different .
________
and by the way – why did you do it this way? ( via slider)
you can combine all your videos in one youtube playlist – without generating a playlist on youtube. ( this will be the best way – because i think the transitions between those videos are gone).

this could be for your videos an iframe code:
<iframe src="https://www.youtube-nocookie.com/embed/sATEt-81AT8?enablejsapi=1&ecver=2&controls=0&cc_load_policy=1&rel=0&showinfo=0&autoplay=1&color=white&iv_load_policy=3&loop=1&playlist=QU0MCwH9cIU,f7Oy2fySTHM,DWRUW1oSLxI,JGt8g7Ms0zA,PGrBLAci8tQ,SlEXdbUgMuQ,kjA-GLzPMfQ,X-qPTwLUBAM" frameborder="0" allow="autoplay; encrypted-media" allowfullscreen></iframe>

you see the first video is single – and at the end there are comma separated the other VideoIDs.

now to your setup to get a responsive youtube setup:
click to enlarge:

put this into your page on top in a code-block element and give to the code-block element a custom-class: fullvideo

<div class="avia-video avia-video-16-9" itemprop="video" itemtype="https://schema.org/VideoObject">
<div class="avia-iframe-wrap">
	<iframe src="https://www.youtube-nocookie.com/embed/sATEt-81AT8?enablejsapi=1&ecver=2&controls=0&cc_load_policy=1&rel=0&showinfo=0&autoplay=1&color=white&iv_load_policy=3&loop=1&playlist=QU0MCwH9cIU,f7Oy2fySTHM,DWRUW1oSLxI,JGt8g7Ms0zA,PGrBLAci8tQ,SlEXdbUgMuQ,kjA-GLzPMfQ,X-qPTwLUBAM" frameborder="0" allow="autoplay; encrypted-media" allowfullscreen></iframe>
</div>
</div>

go to your functions.php of your child-theme and insert:

function youtube_full_width_with_shortcode(){
?>
<script>
(function($){
   $('.fullvideo').closest('.content').css( 'padding' , '0px' );
   $('.fullvideo').closest('.container').css({"max-width": "100%", "padding": "0" });
   $('.fullvideo .avia-video').css('margin-bottom', '0px' );
   $('.fullvideo .avia-iframe-wrap').css('margin-bottom', '0px' );
})(jQuery);
</script>
<?php
}
add_action('wp_footer', 'youtube_full_width_with_shortcode');

see Result: https://webers-testseite.de/youtube-playlist-embed/

No Plugin for creating a child theme please !!!

First: Enfold got a wonderful Documentation: https://kriesi.at/documentation/enfold/

Second : View here : https://kriesi.at/documentation/enfold/how-to-install-enfold-theme/ – there is a predefined Child-Theme !

Here are some infos on why a child-theme is a nice thing: https://kriesi.at/documentation/enfold/how-to-install-enfold-theme/#why-child-theme

To have on both sides a box-shadow you can add two rules to one:
this works this way because there is no place on top – bottom – if so you had to have 4 defintions for each side with background-color shadow to those sides which you don’t want to have shadow ( on white background it is than a white shadow.

body#top {
    box-shadow: 5px 0 10px #666, -5px 0 10px #666;
}

first is x value, second y-value, third distance (it makes the blur) fourth is color

___________

or in your case because body and wrap-all are congruently

body {
    box-shadow: 5px 0 10px  #666;
}
#wrap_all {
    box-shadow: -5px 0  10px  #666;
}

https://webkit.org/blog/6784/new-video-policies-for-ios/

that html5 way seems to be at the moment the only way to do it. Advanced Layerslider can use this for selfhosted videos – so this will work on your iphone / ipad ( with IOS newer than 10)
advantage of that – it will be responsive too – like in the fullwidth slider of Enfold.

if you got your youtube link take the embed variant
https://www.youtube.com/embed/6jE1jxFB2Ic

you can add different parameters to the link https://developers.google.com/youtube/player_parameters?hl=de/#Parameters

the first parameter after the videoID had to be introduced by a question mark – all following parameters added by an ampersand
so autoplay should make of the link on top:
https://www.youtube.com/embed/6jE1jxFB2Ic?autoplay=1

for having the link in lightbox add the link manually to your target( image , text etc.) and add iframe=true
so first with question mark second parameter added by ampersand :
https://www.youtube.com/embed/6jE1jxFB2Ic?autoplay=1&iframe=true

or do you mean the background scroll when a lightbox is opend and you scroll ?

Try this instead in your functions.php of your child theme:

add_action('wp_footer', 'custom_lightbox_script');
function custom_lightbox_script(){
?>
<script type="text/javascript">
(function($) {
    function a() {
      $('body').on('click', '.lightbox-added', function() {
        if($('.mfp-bg').length >= 1) {
          $('html').css("overflow-y", "hidden");
        } 
      });
      
      $('body').on('click', function() {
        setTimeout( function() {
          if($('.mfp-bg').length == 0) { 
            $('html').css("overflow-y", "scroll");
          }
        },500);   
      });
    }
  a(); 
})(jQuery);
</script>
<?php
}

you can see here normal Enfold Behavior: https://kriesi.at/themes/enfold-2017/elements/image/ – klick on the darkend image in the center and then scroll

you can see here behavior with that code: https://webers-testseite.de/lightbox-scroll-behavior/

this is a nice – very small self hosted video.
Use instead the advanced layerslider :
click to enlarge:

the code at the bottom ( do not on top a background-image) is the video which you can declare as background-video.
put in the code:

<video playsinline autoplay loop muted preload="metadata" style="min-width:100vw; min-height:56vw;" >
<source src="https://finanzengel.de/wp-content/uploads/2018/09/Finanzengel-Sachsen.mp4" type="video/mp4">
<img src="https://finanzengel.de/wp-content/uploads/2018/09/himmel.jpg" title="Your browser does not support the video tag">
</video>

see here ( i will go back to my video as soon as you have seen and prooved it on your iphone) : https://webers-testseite.de/weber/

maybe this is a selfhosted video – there are workaround for that. But a 120MB mp4 is to big for that. – Not only because of traffic but definitly because of performance reasons.
But consider if it is really necessary to show a video on mobile devices, or if a fallback image would not be enough anyway.
Most of the CMS and nearly all WordPress Themes got a lot of troubles with youtube background video playing on Mobile – especially on Iphone/Ipads.

Nevertheless there is one thing i found vor Divi – which we can transfer to Enfold too. Divi has the same troubles to play those youtube videos as background.

If this corresponds to your ideas, then I can tell you how we can solve this with a small plugin. Check if the test page runs on your mobile phone or Ipad. : https://webers-testseite.de/carinda/

_________

Offtopic ?:
And by the way, you’re not the only one asking for help here. Also other participants here have the same desires as you. But difficult topics like yours are not as easy to answer as many other simpler questions.
For example, I have now searched 8 hours for the solution to your question. May i charge you for that. ;) :lol
Have you ever been to other support forums? Obviously not, because here you got help often with very complex php and javascript code is quite unusual on the other boards. Many topic creators don’t even have their own support forums, but only use those of the themes resellers.

And if I didn’t need the solution for my customers as well, I wouldn’t be able to make such an effort for you either.
How much time do you think a mod can spend on one topic to make such a board fit for all? 5 minutes? !

by the way Erin – your individual Links to f.e. about should have the absolute path – because if you are not on the landing page (f.e. on a portfolio page) the #about link has no function (maybe the /#about will work)