style.css

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

.game{
  width: 100%;
  height: 500px;
  border-bottom: 30px solid rgb(35, 160, 35) ;
  margin: 0 auto;
  position: relative;
  overflow: hidden;
  background: linear-gradient(#87ceeb, #e0f6ff);
}

.pipe {
  position: absolute;
  bottom: 0;
  width: 80px;
  right: -80px;
  animation: pipe-animation 1.5s infinite linear; 
}

.mario {
  width: 150px;
  position: absolute;
  bottom: 0;
}

 .jump{
  animation: jump 500ms ease-out;
 }


 .clouds {
  position: absolute;
  width: 550px;
  animation: clouds-animation 20s infinite linear;

 }

 @keyframes pipe-animation {
  from {
    right: -80px;
  }
  to {
    right: 100%;
  }

}

@keyframes jump {

0% {
  bottom: 0;
}

40% {
  bottom: 180px;
}

50% {
  bottom: 180px;
}

60% {
  bottom: 180px;
}

 100% {
  bottom: 0;
 }

}

@keyframes clouds-animation {
  from{
    right: -550px;
  }

  to {
    right: 100%;


  }

}