*,
*::before,
*::after {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  padding: 0;
  height: 100%;
  font-family: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  background: #070b18;
  color: #f7f7ff;
}

body {
  display: flex;
  align-items: stretch;
  justify-content: center;
}

#app {
  max-width: 1200px;
  width: 100%;
  margin: 0 auto;
  padding: 16px;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.app-header,
.app-footer {
  text-align: center;
}

.app-header h1 {
  margin: 0;
  font-size: 1.8rem;
  letter-spacing: 0.03em;
}

.app-footer {
  font-size: 0.85rem;
  color: #a6accd;
}

.app-footer code {
  background: #14172b;
  padding: 2px 4px;
  border-radius: 4px;
}

.game {
  display: grid;
  grid-template-columns: minmax(0, 1.1fr) minmax(0, 1.4fr);
  gap: 16px;
}

.panel {
  background: radial-gradient(circle at top left, #222b4a, #14172b);
  border-radius: 16px;
  padding: 16px 18px 18px;
  box-shadow: 0 18px 45px rgba(0, 0, 0, 0.5);
  border: 1px solid rgba(255, 255, 255, 0.04);
}

.panel h2 {
  margin-top: 0;
  margin-bottom: 12px;
  font-size: 1.2rem;
  color: #e5e8ff;
}

.face-container {
  margin-top: 8px;
  width: 100%;
  aspect-ratio: 4 / 3;
  border-radius: 14px;
  background: #050713;
  border: 1px solid rgba(255, 255, 255, 0.05);
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}

.face-container img {
  max-width: 100%;
  max-height: 100%;
  object-fit: contain;
}

.options-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
  margin-top: 8px;
}

.option-card {
  position: relative;
  border-radius: 12px;
  overflow: hidden;
  cursor: pointer;
  border: 2px solid transparent;
  background: #050713;
  transition: transform 0.14s ease-out, box-shadow 0.14s ease-out, border-color 0.14s ease-out,
    filter 0.14s ease-out;
  aspect-ratio: 1;
  perspective: 800px;
}

a.option-card {
  text-decoration: none;
  color: inherit;
  display: block;
}

.option-card-inner {
  position: absolute;
  inset: 0;
  z-index: 0;
  transform-style: preserve-3d;
  transition: transform 0.6s ease-in-out;
}

a.option-card:hover .option-card-inner {
  transform: rotateY(180deg);
}

.option-card-front,
.option-card-back {
  position: absolute;
  inset: 0;
  backface-visibility: hidden;
  -webkit-backface-visibility: hidden;
}

.option-card-front {
  transform: rotateY(0deg);
}

.option-card-back {
  transform: rotateY(180deg);
}

.option-card-front img,
.option-card-back img {
  width: 100%;
  height: 100%;
  display: block;
  object-fit: cover;
}

.option-card-caption {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  padding: 10px 12px;
  background: linear-gradient(to top, rgba(0, 0, 0, 0.9), rgba(0, 0, 0, 0.6));
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.option-card-caption-title {
  font-weight: 600;
  font-size: 1rem;
  color: #fff;
}

.option-card-caption-sub {
  font-size: 0.8rem;
  color: rgba(255, 255, 255, 0.85);
}

.option-card img {
  width: 100%;
  height: 100%;
  display: block;
  object-fit: cover;
}

.option-card:hover {
  transform: translateY(-2px);
  box-shadow: 0 10px 25px rgba(0, 0, 0, 0.6);
  border-color: rgba(255, 255, 255, 0.2);
}

.option-card.disabled {
  cursor: default;
  pointer-events: none;
  filter: grayscale(0.25) brightness(0.8);
}

.option-card.correct {
  border-color: #45ff9c;
  box-shadow: 0 0 0 1px rgba(69, 255, 156, 0.4), 0 12px 28px rgba(0, 0, 0, 0.9);
}

.option-card.incorrect {
  border-color: #ff5e7d;
  box-shadow: 0 0 0 1px rgba(255, 94, 125, 0.4), 0 12px 28px rgba(0, 0, 0, 0.9);
}

.option-card.correct::after {
  content: '✔';
  position: absolute;
  top: 8px;
  right: 10px;
  z-index: 2;
  font-size: 1.2rem;
  color: #45ff9c;
  text-shadow: 0 0 8px rgba(0, 0, 0, 0.8);
}

.option-card.incorrect::after {
  content: '✖';
  position: absolute;
  top: 8px;
  right: 10px;
  z-index: 2;
  font-size: 1.2rem;
  color: #ff5e7d;
  text-shadow: 0 0 8px rgba(0, 0, 0, 0.8);
}

.status-message {
  margin-top: 10px;
  min-height: 1.4em;
  font-weight: 500;
}

.status-message.correct {
  color: #7cffc7;
}

.status-message.incorrect {
  color: #ff9cb0;
}

.info-message {
  font-size: 0.9rem;
  color: #c3c7ff;
}

.error-message {
  font-size: 0.9rem;
  color: #ff9cb0;
}

.primary-button {
  margin-top: 12px;
  padding: 8px 16px;
  border-radius: 999px;
  border: none;
  background: linear-gradient(135deg, #6366f1, #ec4899);
  color: #fdfcff;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  font-size: 0.85rem;
  cursor: pointer;
  box-shadow: 0 12px 28px rgba(0, 0, 0, 0.6);
  transition: transform 0.12s ease-out, box-shadow 0.12s ease-out, filter 0.12s ease-out,
    opacity 0.12s ease-out;
}

.primary-button:disabled {
  opacity: 0.45;
  cursor: default;
  box-shadow: none;
}

.primary-button:not(:disabled):hover {
  transform: translateY(-1px);
  box-shadow: 0 16px 36px rgba(0, 0, 0, 0.8);
  filter: brightness(1.03);
}

@media (max-width: 800px) {
  .game {
    grid-template-columns: minmax(0, 1fr);
  }

  .panel {
    padding: 14px 14px 16px;
  }
}