header {
  text-align: center;
  border-bottom: 1%;
  border-bottom-style: solid;
  border-bottom-color: grey;
  width: 90%;
  margin: auto;
}

h1 {
  text-shadow: 2px 2px 5px grey;
}

img,video,audio,object {
  display: block;
  width: 90%;
  margin: auto;
  margin-top: 1em;
  margin-bottom: 1em;
  box-shadow: 5px 5px 5px grey;
}

object,video {
  height: 600px;
}