body {
  margin: 0;
  font-family: Tahoma, sans-serif;
  background: url('https://upload.wikimedia.org/wikipedia/en/2/27/Bliss_%28Windows_XP%29.png') center center / cover;
  overflow: hidden;
}

#desktop {
  position: absolute;
  top: 0; left: 0; right: 0; bottom: 40px;
  padding: 10px;
}

.icon {
  width: 64px;
  text-align: center;
  margin: 10px;
  cursor: pointer;
  display: inline-block;
  color: white;
  text-shadow: 1px 1px black;
}

.icon img {
  width: 48px;
  height: 48px;
}

.window {
  width: 600px;
  height: 400px;
  background: white;
  border: 2px solid blue;
  display: none;
  position: absolute;
  top: 80px;
  left: 80px;
  box-shadow: 5px 5px 10px rgba(0,0,0,0.5);
  flex-direction: column;
}

.titlebar {
  background: navy;
  color: white;
  display: flex;
  justify-content: space-between;
  padding: 5px;
  cursor: move;
}

.titlebar .buttons button {
  background: lightgray;
  border: none;
  margin-left: 5px;
  width: 25px;
}

iframe {
  flex: 1;
  width: 100%;
  height: 100%;
  border: none;
}

#taskbar {
  position: absolute;
  bottom: 0;
  left: 0;
  height: 40px;
  width: 100%;
  background: #003399;
  display: flex;
  align-items: center;
  padding: 0 10px;
}

#taskbar button {
  background: lightgray;
  border: 1px solid gray;
  margin-right: 5px;
  padding: 5px 10px;
}