main{
  background-color: black;
}
.myVideo {
  width: 100%;
  margin: 0 auto;
  background-color: black;
  color: black;
  display: block;
}


.marca-dagua{
text-align: center;
background-color: gray;
color: black;
height: 200px;
width: 300px;
position:absolute;
border-radius: 100px;
margin-top: 220px;
margin-left: 30px;
padding: 10px;
z-index:999;   //para sobrepor o video
}