I am trying to embed a youtube video on bearblog. My goal is for the video to be variable width (for viewing on phone / computer), and for youtube fullscreen capability to be enabled.
I followed the instructions here https://stackoverflow.com/a/49887085/10792715 and here YouTube iframe embed - full screen
/* Set your aspect ratio */
.video-container {
  position: relative;
  overflow: hidden;
  height: 0;
  /*  width: 100%; */
  padding-bottom: 56.25%; /* creates a 16:9 aspect ratio */
}
.video-container iframe{
    position: absolute;
    top:0;
    left:0;
    width: 100%;
    height: 100%
} 
.video-container embed {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  max-width: 100%;
}
/* And set the max-width of the parent element */
.video-wrap {
  width: 100%;
  max-width: 600px;
}
.video {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  border: 0;
}
and I embedded the video as
<div class="video-wrap">
  <div class="video-container">
    <iframe 
       src="https://www.youtube.com/watch?v=dQw4w9WgXcQ" 
       title="Some title" 
       allowfullscreen></iframe>
  </div>
</div>  
However, even though the video is variable width, there is no fullscreen capability. It simply says
Full screen is unavailable.
Find out more
I tried all kinds of tricks
allowFullScreen="true"
allowFullScreen="allowFullScreen"
allowFullScreen
allowfullscreen="allowfullscreen"
mozallowfullscreen="mozallowfullscreen" 
msallowfullscreen="msallowfullscreen" 
oallowfullscreen="oallowfullscreen" 
webkitallowfullscreen="webkitallowfullscreen"
but none worked.
PS. Following the advice of @Marco Aurelio Fernandez Reyes, I checked the console, and this is what I got:
<div class="video-wrap">
<div class="video-container">
<iframe 
src="https://www.youtube.com/watch?v=dQw4w9WgXcQ" 
title="Some title"></iframe>
</div>
</div>
i.e., the fullscreen commands are just ignored.