body {
  margin: 0;
  background: #fff; 
}
video { 
  position: fixed;
  right: 0;
  bottom: 0;
  min-width: 100%;
  min-height: 100%;
  width: 80%;
  height: 80%;
  z-index: -100;
  background: url('Mode d\'emploi-Essentiel RP.jpg') #000 no-repeat center;
  background-size: 75%;
  transition: 1s opacity;
}
.stopfade { 
   opacity: .5;
}

a {
  display: inline-block;
  color: #fff;
  text-decoration: none;
  background:rgba(0,0,0,0.5);
  padding: .5rem;
  transition: .6s background; 
}
a:hover{
  background:rgba(0,0,0,0.9);
}

@media screen and (max-width: 500px) { 
  div{width:20%;} 
}
@media screen and (max-device-width: 800px) {
  #bgvid { display: none; }
  #video_mobile { display: inline;text-align: center; }

}
@media screen and (min-device-width: 800px) {
  #video_mobile { display: none;}
}