body {
  font-family: "Comic Sans MS", Arial, sans-serif;
  text-align: center;
  background: #f7faff;
  color: #333;
  margin: 0;
  padding: 20px;
}

h1 {
  font-size: 2em;
  margin-bottom: 10px;
}

.controls {
  margin-bottom: 20px;
}

select, button, input {
  margin: 5px;
  padding: 8px 12px;
  border-radius: 8px;
  border: 1px solid #ccc;
  font-size: 1em;
}

button {
  background-color: #4caf50;
  color: white;
  cursor: pointer;
}

button:hover {
  background-color: #45a049;
}

.problem-box {
  background: white;
  border-radius: 12px;
  padding: 20px;
  box-shadow: 0 2px 6px rgba(0,0,0,0.1);
  display: inline-block;
  min-width: 250px;
}

#problem {
  font-size: 2em;
  margin-bottom: 15px;
}

.feedback {
  font-weight: bold;
  margin-top: 10px;
}

.feedback.correct {
  color: green;
}

.feedback.wrong {
  color: red;
}

.solution {
  margin-top: 5px;
  font-style: italic;
  color: #666;
}

.stats {
  margin-top: 20px;
  font-size: 1.2em;
}