/* =========================================
   QuizLounge — Global IELTS App Styles
   Responsive: mobile-first
   ========================================= */

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  background: #f8f9fa;
  color: #212529;
}

/* ---- Responsive typography ---- */
@media (max-width: 575px) {
  h1, .h1 { font-size: clamp(1.6rem, 6vw, 2.5rem) !important; }
  h2, .h2 { font-size: clamp(1.3rem, 5vw, 2rem) !important; }
  h3, .h3 { font-size: clamp(1.1rem, 4.5vw, 1.5rem) !important; }
  .display-5 { font-size: clamp(1.6rem, 6vw, 2.5rem) !important; }
  .lead { font-size: 1rem !important; }
}

/* ---- Responsive utilities ---- */
@media (max-width: 575px) {
  .mobile-full { width: 100% !important; }
  .mobile-center { text-align: center !important; }
  .mobile-stack { flex-direction: column !important; gap: 0.5rem; }
  .hide-mobile { display: none !important; }
}

/* ---- Quiz two-column layout (passage + questions) ---- */
@media (min-width: 992px) {
  .quiz-two-col {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1.5rem;
    align-items: start;
  }
  .quiz-passage-sticky {
    position: sticky;
    top: 80px;
    max-height: calc(100vh - 100px);
    overflow-y: auto;
  }
}
@media (max-width: 991px) {
  .quiz-passage-sticky {
    max-height: 250px;
    overflow-y: auto;
    margin-bottom: 1rem;
  }
}

/* ---- Forms focus ring ---- */
.form-control:focus, .form-select:focus {
  border-color: #667eea;
  box-shadow: 0 0 0 0.2rem rgba(102,126,234,0.2);
}

/* ---- Loading skeleton ---- */
.skeleton {
  background: linear-gradient(90deg, #f0f0f0 25%, #e0e0e0 50%, #f0f0f0 75%);
  background-size: 200% 100%;
  animation: skeleton-shimmer 1.5s infinite;
  border-radius: 6px;
}
@keyframes skeleton-shimmer {
  0% { background-position: 200% 0; }
  100% { background-position: -200% 0; }
}