body {
  overflow: hidden;
}

#top {
  position: absolute;
  left: 0px;
  top: 0px;
  width: 100%;
  height: 160px;
}

#left {
  position: absolute;
  left: 0px;
  top: 160px;
  width: 300px;
  bottom: 0px;
}

#main {
  position: absolute;
  left: 300px;
  top: 160px;
  right: 0px;
  bottom: 0px;
}

iframe {
  border: none;
  height: 100%;
  width: 100%;
}