body {
  background: #f7f7f7;
  font-family: Arial, sans-serif;
  text-align: center;
}

h1 {
  margin-top: 40px;
  color: #222;
}

#game-box {
  background: white;
  width: 350px;
  margin: 50px auto;
  padding: 30px 20px;
  border-radius: 12px;
  box-shadow: 0 0 8px #bbb;
}

input[type="number"] {
  width: 100px;
  font-size: 1.1em;
  padding: 6px;
  margin-right: 12px;
  margin-bottom: 10px;
}

button {
  font-size: 1em;
  padding: 7px 20px;
  border: none;
  border-radius: 5px;
  background: #2196f3;
  color: white;
  cursor: pointer;
  margin-bottom: 10px;
}
button:hover {
  background: #1769aa;
}

#info {
  font-size: 1.2em;
  margin-top: 14px;
  min-height: 2em;
}

#attempts {
  margin-top: 8px;
  color: #888;
}

.hidden {
  display: none;
}

@media (min-width: 728px) {
  body,
  #game-box,
  input[type="number"],
  button,
  #info,
  #attempts {
    width: 95%;
    font-size: 130%;
  }
}