body {
  font-family: Helvetica, Verdana, sans-serif;

  margin: 0;

  font-size: 15px;
  line-height: 1.5;

  background-color: #aee9fc;
  width: 100%;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;

  background-image: url(" ");
  background-repeat: no-repeat;
  background-attachment: fixed;
  background-size: cover;
}

h1 {
  font-family: "Segoe UI", Arial, sans-serif;
  font-weight: 400;
  margin: 10px 0;
  font-size: 36px;
}

button,
input {
  font: inherit;
}

div {
  border-radius: 15px;
  background-color: white;
  width: 95%;
  margin: 10px 20px 10px 20px;
  padding: 10px 0 10px 0;
  max-width: 400px;
}

input {
  font-size: 25px;
  width: 60%;
  max-width: 220px;
  text-align: center;
}

p {
  padding-left: 10px;
  padding-right: 10px;
}

#chooseDifficulty button {
  border-color: #0a4ffc;
  height: 60px;
  width: 60px;
  border-radius: 15px;
  background-color: #0a4ffc;

  color: white;
  margin: 10px 0 10px 0;
}

#game button {
  border-color: #0a4ffc;
  height: 30px;
  width: 60%;
  max-width: 220px;
  border-radius: 15px;
  background-color: #0a4ffc;
  color: white;
  margin: 10px 0 10px 0;
}

#offer button {
  border-color: #66cc00;
  height: 30px;
  width: 60%;
  max-width: 220px;
  border-radius: 15px;
  background-color: #66cc00;
  color: white;
  margin: 10px 0 10px 0;
}

#game {
  display: none;
}

#offer {
  display: none;
  background-color: rgb(255, 255, 255, 0.7);
}