body {
  margin: 0;
  padding: 0;
}

nav, .navbar {
  background-color: #000000;
  color: #ffffff;
  padding: 10px;
  text-align: center;
}

nav a, .navbar {
  color: #ffffff;
}

header {
  background-color: #999999;
  padding: 50px;
  text-align: center;
}

.container {
  display: flex;
  justify-content: center;
  align-items: center;
  height: calc(100vh - 100px)
}

iframe, .videocontainer {
  width: 100%;
  height: 100%;
}

@media screen and (max-width: 768px) {
  h1 {
    font-size: 1.5rem;
  }

  .navbar {
    font-size: 1rem;
  }
}

@media screen and (max-width: 480px) {
  h1 {
    font-size: 1.2rem;
  }

  .navbar {
    font-size: 0.8rem;
  }

  .video-container {
    padding-bottom: 75%; /* 4:3 aspect ratio */
  }
}