body {
  height: 100%;
  width: 100%;
  margin: 0;
}

p {
  font-size: 30px;
  text-align: center;
  color: blue;
}

#container {
  position: relative;
  height: 400px;
  width: 90%;
  border: 2px solid red;
  background-color: aliceblue;
  margin-left: 4%;
  overflow: hidden;
}

#bird {
  position: absolute;
  background: url('bird.png');
  height: 42px;
  width: 65px;
  background-size: contain;
  background-repeat: no-repeat;
  top: 20%;
  left: 15%;
}

.pole {
  position: absolute;
  height: 130px;
  width: 50px;
  background-color: red;
  right: -50px;
}

#pole_1 {
  top: 0;
}

#pole_2 {
  bottom: 0;
}

#score_div {
  text-align: center;
  font-size: 40px;
}

#restart_btn {
  position: absolute;
  top: 0;
  width: 100%;
  padding: 20px;
  background-color: fuchsia;
  color: white;
  font-size: 35px;
  border: none;
  cursor: pointer;
  display: none;
}