body {
  background-image: url(https://images.unsplash.com/photo-1502570149819-b2260483d302?w=500&auto=format&fit=crop&q=60&ixlib=rb-4.0.3&ixid=M3wxMjA3fDB8MHxzZWFyY2h8M3x8bnVtYmVyc3xlbnwwfHwwfHx8MA%3D%3D);
  background-size: cover;
  background-repeat: no-repeat;
  min-height: 100%;
  background-position: center;
}
.header {
  display: flex;
  justify-content: center;
}
#heading {
  font-family: 'Kanit', sans-serif;
  font-size: 40px;
  color: #252525;
}
.container {
  background-color: rgb(240,240,240);
  border: 5px rgb(189, 180, 180) ridge;
  width: 30%;
  padding: 20px;
  margin-top: 50px;
}
h3, #text-h3 {
  font-family: 'Kanit', sans-serif;
  font-size: 20px;
  color: #252525;
}
#input-guess {
  font-family: 'Kanit', sans-serif;
  font-size: 15px;
  padding: 10px;
  width: 40%;
  border: none;
}
#btn {
  background-color: #185ADB;
  font-family: 'Kanit', sans-serif;
  font-size: 15px;
  color: #fff;
  margin-top: 20px;
  padding: 20px;
  border-radius: 20px;
  border: none;
  width: 100%;
  letter-spacing: 5px;
}
@media all and (max-width: 800px) {
  .container {
    width: 60%;
  }
}