style.css

*{
  box-sizing: border-box;
}
::selection{
  background-color: #eee;
  color: #2c82ff;
}
body{
  font-family: 'Courier New', Courier, monospace;
  padding: 0;
  margin: 0;
  background-color: #2c82ff;
  position: relative;
}
@media(max-width:767px){
  body{
    background-image: none;
    background-color: #eee;
  }
}
.container{
  user-select: none;
  width: 600px;
  margin: auto;
  margin-top: 200px;
  background-color: #eeee;
  padding: 20px;
  border-radius: 10px;
  /* filter: blur(0px); */
  h1{
    text-align: center;
    color: #2c82ff;
  }
}
@media(max-width:767px) {
  body .container{
    width: 100%;
    margin-top: 0;
    border-radius: 0;
    margin-top: 0px;
    h1{
      font-size: 27px;
    }
  }
}
input{
  padding: 15px;
  border: 1px solid #3333;
  margin-bottom: 20px;
  font-size: 20px;
  font-family: 'Courier New', Courier, monospace;
  text-align: center;
  font-weight: bold;
  border-radius: 10px;
  position: relative;
  color: black;
  position: relative;
  width: 100%;  
  word-break: keep-all;
}
input:focus{
  outline: none;
}
@media(max-width:767px) {
  body input{
    padding: 10px;
    border-radius: 0;
    font-size: 20px;
  }
}
.result{
  min-height: 54px;
  display: flex;
  justify-content: center;
  align-items: center;
  text-align: center;
  flex-direction: column;
  line-height: 1.7;
  font-size: 19px;
  color: black;
  overflow-x: hidden;
  word-break: keep-all;
}
.result span{
  color: red;
}
.result h4{
  color: #2c82ff;
  margin-block: 0 0;
}
.container .btn{
  position: absolute;
  top: 18px;
  right: 11px;
  font-size: 12px;
  padding: 4px;
  background-color:#eee;
  border-radius: 14px;
  color: #333;
  cursor: pointer;
  transition: 0.3s;
}
.btn:hover{
  background-color: rgba(255, 0, 0);
  color: white;
  opacity: 1;
}
@media(max-width:767px){
  .container .btn{
    top: 13px;
  }
}