body {
  font-family: Arial, sans-serif;
  background: #0f172a;
  color: white;
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 100vh;
}

.container {
  width: 90%;
  max-width: 500px;
}

.card {
  background: #1e293b;
  padding: 20px;
  border-radius: 12px;
  box-shadow: 0 5px 20px rgba(0,0,0,0.5);
}

/* Utility */
.hidden {
  display: none !important;
}

/* Buttons */
button {
  width: 100%;
  padding: 10px;
  margin-top: 10px;
  background: #3b82f6;
  border: none;
  color: white;
  border-radius: 8px;
  cursor: pointer;
  transition: 0.2s;
}

button:hover {
  background: #2563eb;
}

/* Quiz Answers */
.answers button {
  margin: 5px 0;
  background: #334155;
}

.answers button.selected {
  background: #22c55e;
}

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

/* Start screen */
.start-screen {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

select,
input[type="range"] {
  padding: 10px;
  border-radius: 8px;
  border: none;
  background: #334155;
  color: white;
}

/* Difficulty buttons */
.difficulty-options {
  display: flex;
  gap: 10px;
}

.difficulty-options button {
  flex: 1;
  padding: 10px;
  background: #334155;
}

.difficulty-options button.active {
  background: #3b82f6;
}

/* Start button */
.start-btn {
  padding: 12px;
  font-size: 16px;
  font-weight: bold;
  background: linear-gradient(135deg, #3b82f6, #6366f1);
  border-radius: 10px;
}

.start-btn:hover {
  transform: scale(1.05);
}

/* Animation */
.fade {
  animation: fadeIn 0.4s ease-in-out;
}

@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(10px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* Answer states */
.correct {
  background: #22c55e !important;
}

.wrong {
  background: #ef4444 !important;
}

/* Result screen */
.result-summary {
  text-align: center;
  margin-bottom: 20px;
}

.score {
  font-size: 24px;
  font-weight: bold;
}

/* Review (single-item mode) */
.review-container {
  margin-top: 20px;
}

.review-item {
  background: #1e293b;
  padding: 20px;
  border-radius: 12px;
  border-left: 5px solid #3b82f6;
}

.review-item.correct {
  border-left-color: #22c55e;
}

.review-item.wrong {
  border-left-color: #ef4444;
}

/* Pagination */
.pagination {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-top: 15px;
}

.pagination button {
  width: auto;
  padding: 8px 12px;
}

@media (max-width: 480px) {
  .card {
    padding: 15px;
  }

  .score {
    font-size: 20px;
  }
}