article, aside, audio, canvas, datalist, details, figcaption, figure,
footer, header, hgroup, main, menu, nav, output, progress, section, summary {
  display: block;
}
h1{ 
  font-size: 4em;
  margin: 0.67em 0;
  text-align: center;
}
video {
  width: 60%;
  height: auto;
}
#video-section {
  text-align: center;
  margin: 20px auto;
}
#video-section h2{
  max-width: 60%;
  margin: 0 auto;
  text-align: start;
}
#audio-section {
  text-align: center;
  margin: 20px auto;
}
audio {
  max-width: 60%;
  height: 60px;
  margin: 0 auto;
}
article {
  max-width: 50%;
  margin: 0 auto;
  padding: 20px;
  border: 1px solid #ccc;
  border-radius: 5px;
  background-color: #ffffff;
}
article h2 {
  font-size: 2em;
  margin-top: 0;
  text-align: center;
}
body {
  font-family: Arial, sans-serif;
  line-height: 1.6;
  background-color: #ffffff;
  color: #333;
  margin: 0;
}
#background {
  position: fixed;
  left: 50%;
  transform: translateX(-50%);
  background-color: #dfdfdf;
  width: 65%;
  height: 100%;
  top: 0;
  z-index: -1;
}
footer {
  text-align: center;
  padding-top: 10px;
  padding-bottom: 0;
  margin-top: 60px;
  background-color: #f8f8f8;
  border-top: 1px solid #ccc;
  position: relative;
  bottom: 0;
  height: 65px;
}
footer p {
  margin: 0;
}