body {
  margin: 0;
  background-color: #f4f4f4;
  display: flex;
  justify-content: center;
  align-items: center;
  height: 100vh;
  font-family: sans-serif;
}

.container {
  display: flex;
  flex-direction: column;
  align-items: center;
}

.intro {
  text-align: center;
  margin-bottom: 20px;
}

.intro h1 {
  margin: 0;
  font-size: 32px;
}

.intro h3 {
  margin: 0;
  font-weight: normal;
  color: #555;
}

.game {
  position: relative;
  width: 800px;
  height: 200px;
  background: #fff;
  border: 2px solid #000;
  overflow: hidden;
}

#dino {
  position: absolute;
  bottom: 0;
  left: 50px;
  width: 40px;
  height: 40px;
  background: green;
  transition: bottom 0.1s;
}

.jump {
  animation: jump 0.5s linear;
}

@keyframes jump {
  0%   { bottom: 0; }
  50%  { bottom: 100px; }
  100% { bottom: 0; }
}

#obstacle {
  position: absolute;
  bottom: 0;
  right: 0;
  width: 20px;
  height: 40px;
  background: red;
  animation: move 2s linear infinite;
}

@keyframes move {
  0% { right: -20px; }
  100% { right: 100%; }
}

#message {
  position: absolute;
  top: 10px;
  left: 10px;
  font-size: 18px;
}