@import url('https://fonts.googleapis.com/css?family=Poppins:400,500,600,700&display=swap');
*{
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: 'Poppins', sans-serif;
}
body{
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 100vh;
  background: #111;
}
.wrapper{
  width: 450px;
  height: 500px;
  position: relative;
}
img{
  margin-top: -50px;
  height: 450px;
  width: 100%;
  position: absolute;
}
img#bulb-on{
  opacity: 0;
  animation: glow 3s linear infinite;
}
@keyframes glow {
  0%{
    opacity: 1;
  }
  5%{
    opacity: 1;
  }
  70%{
    opacity: 1;
  }
  74%{
    opacity: 0;
  }
  80%{
    opacity: 1;
  }
  84%{
    opacity: 0;
  }
  90%{
    opacity: 1;
  }
  100%{
    opacity: 1;
  }
}
.btn{
  position: absolute;
  bottom: 0;
  left: 50%;
  transform: translateX(-50%);
}
.btn span{
  height: 50px;
  width: 180px;
  display: block;
  text-align: center;
  line-height: 48px;
  background:none;
  color: #fff;
  text-transform: uppercase;
  font-size: 20px;
  cursor: pointer;
  border: 2px solid #fff;
  border-radius: 5px;
  transition: all 0.3s ease;
}
.btn span:hover{
  background: #fff;
  color: #111;
}
#btn:checked ~ .btn span{
  background: #fff;
  color: #111;
}
.btn span:before{
  content: "Turn Off";
}
#btn:checked ~ img#bulb-on{
  animation: none;
}
#btn:checked ~ .btn span:before{
  content: "Turn on";
}
.wrapper input{
  display: none;
}