* {
  box-sizing: border-box;
  font-family: Arial, sans-serif;
}

body {
  background: #f4f6f8;
  display: flex;
  justify-content: center;
  align-items: center;
  height: 100vh;
}

.container {
  width: 420px;
  background: #fff;
  padding: 25px;
  border-radius: 8px;
  box-shadow: 0 10px 25px rgba(0,0,0,0.1);
}

h2, h3 {
  text-align: center;
}

input {
  width: 100%;
  padding: 10px;
  margin: 8px 0;
}

button {
  width: 100%;
  padding: 10px;
  margin-top: 8px;
  background: #3498db;
  color: #fff;
  border: none;
  cursor: pointer;
}

button.secondary {
  background: #2ecc71;
}

button.submit {
  background: #e67e22;
}

.hidden {
  display: none;
}

.top {
  display: flex;
  justify-content: space-between;
  margin-bottom: 10px;
}

ul {
  list-style: none;
  padding: 0;
}

li {
  padding: 10px;
  border: 1px solid #ddd;
  margin: 6px 0;
  cursor: pointer;
}

li.selected {
  background: #dff0ff;
  border-color: #3498db;
}

.correct {
  color: green;
  font-weight: bold;
}

.wrong {
  color: red;
}