:root {
  --primary: #00b894;
  --primary-dark: #019877;
  --bg-light: #fefefe;
  --gray: #ddd;
  --gray-dark: #999;
  --radius: 8px;
  --font: 'Inter', sans-serif;
}

body {
  font-family: var(--font);
  background: linear-gradient(135deg, #dfe9f3 0%, #ffffff 100%);
  padding: 0;
  margin: 0;
  min-height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
  flex-direction: column;
}

.quiz-container {
  background: #fff;
  padding: 30px 28px;
  border-radius: var(--radius);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.1);
  max-width: 600px;
  width: 100%;
  box-sizing: border-box;
  position: relative;
  animation: fadeIn 0.5s ease-in-out;
}

.title {
  font-size: 24px;
  font-weight: 700;
  text-align: center;
  margin-bottom: 12px;
  color: #2d3436;
}

.subtitle {
  font-size: 15px;
  text-align: center;
  margin-bottom: 16px;
  color: #636e72;
}

h2 {
  font-size: 17px;
  font-weight: 600;
  margin-bottom: 12px;
  color: #2d3436;
}

.choice {
  display: block;
  width: 100%;
  margin: 6px 0;
  padding: 12px 16px;
  border: 1px solid var(--gray);
  border-radius: var(--radius);
  background-color: var(--bg-light);
  font-size: 14px;
  text-align: left;
  cursor: pointer;
  transition: all 0.15s ease-in-out;
}

.choice:hover {
  background-color: #e9fff8;
  border-color: var(--primary);
}

.correct {
  background-color: #d4edda !important;
  border-color: #28a745 !important;
  color: #155724 !important;
}

.incorrect {
  background-color: #f8d7da !important;
  border-color: #dc3545 !important;
  color: #721c24 !important;
}

.feedback {
  margin-top: 12px;
  font-size: 13px;
  font-style: italic;
  background: #f1f1f1;
  padding: 10px;
  border-left: 3px solid #ccc;
  border-radius: 4px;
  color: #555;
}

.btn-group {
  margin-top: 20px;
  display: flex;
  gap: 10px;
  justify-content: center;
}

.btn {
  padding: 10px 20px;
  font-size: 14px;
  font-weight: 500;
  border: none;
  border-radius: var(--radius);
  cursor: pointer;
  transition: all 0.2s ease-in-out;
}

.primary {
  background-color: var(--primary);
  color: white;
}

.primary:hover {
  background-color: var(--primary-dark);
}

.secondary {
  background-color: var(--gray-dark);
  color: white;
}

.secondary:hover {
  background-color: #666;
}

.progress-bar {
  height: 6px;
  width: 100%;
  background-color: #e0e0e0;
  border-radius: var(--radius);
  overflow: hidden;
  margin-bottom: 16px;
}

.progress {
  height: 100%;
  background-color: var(--primary);
  width: 0%;
  transition: width 0.3s ease-in-out;
}

#theme-select {
  padding: 8px;
  font-size: 14px;
  margin-bottom: 16px;
  width: 100%;
  border-radius: 6px;
  border: 1px solid #ccc;
}

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

@media (max-width: 480px) {
  .quiz-container {
    padding: 20px;
    max-width: 100%;
  }

  .title {
    font-size: 20px;
  }

  .btn-group {
    flex-direction: column;
  }

  .btn {
    width: 100%;
  }
}

footer {
  margin-top: 5em;
  font-size: 10px;
  a {
    color: grey;
  }
}