<style>
.fullscreen-bg__video {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
}

@media (min-aspect-ratio: 16/9) {
  .fullscreen-bg__video {
    height: 300%;
    top: -100%;
  }
}

@media (max-aspect-ratio: 16/9) {
  .fullscreen-bg__video {
    width: 300%;
    left: -100%;
  }
}

@media (max-width: 767px) {
  .fullscreen-bg {
    background: url('../img/videoframe.jpg') center center / cover no-repeat;
  }

  .fullscreen-bg__video {
    display: none;
  }
}
        h123 {
            color: white;
            text-shadow: 1px 1px 2px black, 0 0 25px blue, 0 0 5px darkblue;
        }
        #rcorners3 {
            border-radius: 25px;
            background: url("../Source/index/nav.jpg");
            background-position: left top;
            background-repeat: repeat;
            padding: 20px;
            width: 1920px;
            height: 20px;
        }  
    @media (max-aspect-ratio: 16/9) {
        .marlist{
            max-width: 1920px;
           
            position: relative;
            margin: auto;
            }  

}
</style>