style.css

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

body{
  background: #3a7bd5;  /* fallback for old browsers */
background: -webkit-linear-gradient(to top, #3a6073, #3a7bd5);  /* Chrome 10-25, Safari 5.1-6 */
background: linear-gradient(to top, #3a6073, #3a7bd5); /* W3C, IE 10+/ Edge, Firefox 16+, Chrome 26+, Opera 12+, Safari 7+ */

}

.title{
  font-size: 2rem;
  text-align: center;
  margin-top: 3rem;
  color: #ADD8E6;
}

.container{
  display: flex;
  align-items: center;
  justify-content: center;
  flex-direction: column;
  height: 100vh;
}

.container2{
  height: 40vh;
  display: flex;
  flex-direction: column;
  padding: 2rem;
  justify-content: center;
  background: #ADD8E6;
  width: 350px;
  margin: 30px 0;
}

.input-element{
  padding: 0.5rem;
  margin: 0.5rem 0;
  border: 0;
  box-shadow:0 0 15px 4px rgba(0,0,0,0.06);
  border-radius:10px;
}

.output{
  margin-top: 1rem;
  width: 350px;
  padding: 10px;
  text-align: center;
  background: #ADD8E6;
  color: black;
  font-size: larger;
  font-weight: bold;
  border-radius: 30px;
}


#mybtn{
  appearance:none;
  -webkit-appearance:none;
  margin-top: 10px;
  padding:8px;
  border:none;
  background-color:#3F51B5;
  color:#fff;
  font-weight:400;
  border-radius:5px;
  width:25%;
}

.hide{
  visibility: hidden;
}
a{
  color:#fff;

}