body {
  margin: 0;
  font-family: "Microsoft JhengHei", sans-serif;
  background-color: #0d0d0d;
  color: #ddd;
}

#nav {
  height: 70px;
  background-color: #1a1a1a;
  display: flex;
  align-items: center;
  justify-content: center;
  border-bottom: 2px solid #ff0000;
  box-shadow: 0 0 10px #ff0000;
}

#nav a {
  margin: 0 15px;
  padding: 10px 20px;
  background-color: #2a2a2a;
  border: 1px solid #ff0000;
  border-radius: 8px;
  text-decoration: none;
  color: #ff4444;
  font-weight: bold;
  transition: 0.3s;
}

#nav a:hover {
  background-color: #ff0000;
  color: #fff;
  transform: scale(1.05);
}

iframe#main {
  width: 100%;
  height: calc(100vh - 70px);
  border: none;
  background-color: #121212;
}