body {
  margin: 0;
  font-family: Arial, sans-serif;
  background: linear-gradient(to bottom right, #0f172a, #000000);
  color: white;
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 100vh;
}
.container {
  background: rgba(30, 41, 59, 0.8);
  padding: 20px 30px;
  border-radius: 15px;
  max-width: 400px;
  width: 100%;
  text-align: center;
}
button {
  background-color: #06b6d4;
  border: none;
  padding: 10px 20px;
  margin-top: 15px;
  border-radius: 10px;
  font-weight: bold;
  cursor: pointer;
  color: black;
}
button:hover {
  background-color: #0e7490;
}
.option-btn {
  display: block;
  width: 100%;
  margin: 8px 0;
  padding: 10px;
  border-radius: 10px;
  border: 1px solid #06b6d4;
  cursor: pointer;
  background-color: #1e293b;
  color: white;
}
.option-btn.correct {
  background-color: green;
  border-color: green;
}
.option-btn.wrong {
  background-color: red;
  border-color: red;
}
.hidden { display: none; }