body {
  margin: 0;
  overflow: hidden;
  height: 100vh;
  width: 100vw;
}

#demo_box {
  width: 90%;
  height: 50vh;
}

#demo {
  text-align: center;
  width: 80%;
  height: fit-content;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translateX(-50%) translateY(-50%);
  border-radius: 20px;
  background-color: #0b0f19;
}

#demo_text {
  color: white;
  font-size: 3vh;
  border-bottom: 1px grey solid;
  padding-bottom: 1vw;
}