/* Modal visibility and centering */
#modal {
  display: none;
  align-items: center;
  justify-content: center;
}

#modal:not(.hidden) {
  display: flex;
}

/* Flip card container */
.flip-card {
  max-width: 400px;
  margin: 0 auto;
  perspective: 1000px;
  cursor: pointer;
  outline: none; /* We'll add custom focus style */
}

/* Flip card inner container */
.flip-card-inner {
  position: relative;
  width: 100%;
  height: 320px;
  text-align: center;
  transition: transform 0.6s cubic-bezier(0.4, 0, 0.2, 1);
  transform-style: preserve-3d;
  border-radius: 0.5rem;
  box-shadow: 0 4px 6px rgb(0 0 0 / 0.1);
}

/* Flipped state */
.flip-card.flipped .flip-card-inner {
  transform: rotateY(180deg);
}

/* Front and back faces */
.flip-card-front,
.flip-card-back {
  position: absolute;
  width: 100%;
  height: 320px;
  backface-visibility: hidden;
  border-radius: 0.5rem;
  display: flex;
  flex-direction: column;
  justify-content: center;
  padding: 1.5rem;
  user-select: none;
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

/* Front face styling */
.flip-card-front {
  background-color: #f9fafb; /* Tailwind gray-50 */
  color: #111827; /* Tailwind gray-900 */
  box-shadow: 0 4px 6px rgb(0 0 0 / 0.1);
  border: 1px solid #e5e7eb; /* Tailwind gray-200 */
}

/* Back face styling */
.flip-card-back {
  background-color: #111827; /* Tailwind gray-900 */
  color: #f9fafb; /* Tailwind gray-50 */
  transform: rotateY(180deg);
  border: 1px solid #374151; /* Tailwind gray-700 */
}

/* Dark mode front/back overrides */
body.dark .flip-card-front {
  background-color: #1f2937; /* Tailwind gray-800 */
  color: #f9fafb; /* Tailwind gray-50 */
  border-color: #374151; /* Tailwind gray-700 */
}

body.dark .flip-card-back {
  background-color: #374151; /* Tailwind gray-700 */
  color: #f9fafb; /* Tailwind gray-50 */
  border-color: #4b5563; /* Tailwind gray-600 */
}

/* Hover flip on desktop only */
@media (hover: hover) and (pointer: fine) {
  .flip-card:hover .flip-card-inner {
    transform: rotateY(180deg);
  }
}

/* Disable hover flip on small screens */
@media (max-width: 640px) {
  .flip-card:hover .flip-card-inner {
    transform: none !important;
  }
}

/* Focus styles for accessibility */
.flip-card:focus {
  outline: 3px solid #2563eb; /* Tailwind blue-600 */
  outline-offset: 3px;
  box-shadow: 0 0 5px 2px rgba(59, 130, 246, 0.7);
}

/* Smooth button transitions */
button {
  transition: background-color 0.3s ease, color 0.3s ease;
}

/* Modal content scrolling */
#modal > div {
  max-height: 80vh;
  overflow-y: auto;
  scrollbar-width: thin;
  scrollbar-color: rgba(156, 163, 175, 0.7) transparent;
}

/* Scrollbar styles for WebKit browsers */
#modal > div::-webkit-scrollbar {
  width: 8px;
}

#modal > div::-webkit-scrollbar-thumb {
  background-color: rgba(156, 163, 175, 0.7);
  border-radius: 4px;
}

#modal > div::-webkit-scrollbar-track {
  background: transparent;
}

/* Responsive container tweaks */
@media (max-width: 640px) {
  #card-container {
    max-width: 90vw;
  }
}

/* Progress display styling */
#progressDisplay {
  font-size: 1.125rem;
  font-weight: 600;
}

/* Buttons focus ring */
button:focus-visible {
  outline: 3px solid #2563eb;
  outline-offset: 2px;
}

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