:root {
  color-scheme: dark;
}

body {
  margin: 0;
  font-family: 'Noto Sans', system-ui, -apple-system, sans-serif;
  background: #0b0f1a;
  color: #f8fafc;
}

.puzzle-main {
  max-width: 1400px;
  margin: 0 auto;
  padding: 32px 20px 60px;
  position: relative;
  z-index: 2;
}

.puzzle-hero {
  background: linear-gradient(135deg, rgba(34, 197, 94, 0.12), rgba(14, 116, 144, 0.1));
  border: 1px solid rgba(34, 197, 94, 0.3);
  border-radius: 24px;
  padding: 28px 28px 24px;
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.35);
}

.puzzle-hero h1 {
  margin: 0 0 12px;
  font-size: clamp(2rem, 3vw, 2.6rem);
  letter-spacing: 0.5px;
}

.puzzle-hero p {
  margin: 0;
  font-size: 1.05rem;
  color: #d6e3f1;
}

.puzzle-controls {
  margin-top: 24px;
  display: grid;
  gap: 16px;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  align-items: start;
}

.puzzle-control {
  background: #111827;
  border-radius: 18px;
  border: 1px solid rgba(148, 163, 184, 0.2);
  padding: 18px;
  box-shadow: inset 0 0 0 1px rgba(15, 23, 42, 0.2);
  display: grid;
  gap: 10px;
}

.puzzle-control label {
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: #94a3b8;
}

.puzzle-control select,
.puzzle-control input[type="file"] {
  background: #0f172a;
  border: 1px solid rgba(148, 163, 184, 0.3);
  color: #f8fafc;
  padding: 10px 12px;
  border-radius: 12px;
  font-size: 0.95rem;
}

.puzzle-control small {
  color: #94a3b8;
  font-size: 0.85rem;
}

.puzzle-primary-button,
.puzzle-secondary-button {
  border: none;
  font-weight: 800;
  letter-spacing: 0.06em;
  padding: 12px 20px;
  border-radius: 999px;
  cursor: pointer;
  text-transform: uppercase;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.puzzle-primary-button {
  background: linear-gradient(135deg, #22c55e, #0ea5a8);
  color: #0b0f1a;
}

.puzzle-secondary-button {
  background: rgba(15, 23, 42, 0.7);
  border: 1px solid rgba(148, 163, 184, 0.3);
  color: #f8fafc;
}

.puzzle-primary-button:hover,
.puzzle-secondary-button:hover {
  transform: translateY(-2px);
  box-shadow: 0 12px 24px rgba(34, 197, 94, 0.3);
}

.puzzle-scoreboard {
  margin-top: 24px;
  display: grid;
  gap: 16px;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
}

.puzzle-score-card {
  background: #111827;
  border-radius: 18px;
  border: 1px solid rgba(148, 163, 184, 0.2);
  padding: 18px;
  box-shadow: inset 0 0 0 1px rgba(15, 23, 42, 0.2);
}

.puzzle-score-card span {
  display: block;
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: #94a3b8;
}

.puzzle-score-card strong {
  font-size: 1.6rem;
  color: #f8fafc;
}

.puzzle-progress {
  margin-top: 8px;
  height: 10px;
  border-radius: 999px;
  background: rgba(148, 163, 184, 0.2);
  overflow: hidden;
}

.puzzle-progress-bar {
  height: 100%;
  width: 0;
  background: linear-gradient(90deg, #22c55e, #0ea5a8);
  transition: width 0.4s ease;
}

.puzzle-board-section {
  margin-top: 28px;
}

.puzzle-instructions {
  font-size: 1rem;
  color: #cbd5f5;
  margin-bottom: 16px;
}

.puzzle-play-area {
  position: relative;
  display: grid;
  grid-template-columns: minmax(280px, 1.1fr) minmax(200px, 0.9fr);
  gap: 24px;
  align-items: stretch;
  min-height: 520px;
}

.puzzle-board {
  background: #0f172a;
  border-radius: 26px;
  border: 1px dashed rgba(148, 163, 184, 0.4);
  box-shadow: inset 0 0 0 1px rgba(15, 23, 42, 0.4);
  position: relative;
  width: 100%;
  max-width: 720px;
  justify-self: center;
  background-image: repeating-linear-gradient(
    45deg,
    rgba(148, 163, 184, 0.08) 0,
    rgba(148, 163, 184, 0.08) 8px,
    rgba(15, 23, 42, 0.5) 8px,
    rgba(15, 23, 42, 0.5) 16px
  );
}

.puzzle-tray {
  background: rgba(15, 23, 42, 0.85);
  border: 1px solid rgba(148, 163, 184, 0.25);
  border-radius: 26px;
  box-shadow: inset 0 0 0 1px rgba(15, 23, 42, 0.4);
  min-height: 320px;
  position: relative;
  overflow: hidden;
}

.puzzle-pieces {
  position: absolute;
  inset: 0;
  pointer-events: none;
}

.puzzle-piece {
  position: absolute;
  border: none;
  padding: 0;
  background: transparent;
  cursor: grab;
  box-shadow: 0 8px 20px rgba(0, 0, 0, 0.4);
  border-radius: 14px;
  transition: box-shadow 0.2s ease, transform 0.2s ease;
  pointer-events: auto;
  touch-action: none;
}

.puzzle-piece canvas {
  display: block;
}

.puzzle-piece:focus-visible {
  outline: 2px solid #22c55e;
  outline-offset: 4px;
}

.puzzle-piece.dragging,
.puzzle-piece.keyboard-active {
  cursor: grabbing;
  z-index: 5;
  box-shadow: 0 16px 30px rgba(34, 197, 94, 0.4);
}

.puzzle-piece.locked {
  cursor: default;
  box-shadow: 0 6px 14px rgba(0, 0, 0, 0.3);
}

.puzzle-actions {
  margin-top: 18px;
  display: flex;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
}

.puzzle-status {
  font-weight: 600;
  color: #f8fafc;
}

.puzzle-final {
  min-height: 100vh;
  padding: 32px 20px 80px;
  display: none;
}

.puzzle-final.active {
  display: block;
}

.puzzle-final-content {
  max-width: 900px;
  margin: 0 auto;
  text-align: center;
}

.puzzle-final-header h2 {
  font-size: clamp(2.2rem, 4vw, 3rem);
  margin-bottom: 12px;
}

.puzzle-final-header p {
  color: #d4e6f5;
  font-size: 1.1rem;
}

.puzzle-final-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  justify-content: center;
  margin-top: 18px;
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

@media (max-width: 900px) {
  .puzzle-play-area {
    grid-template-columns: 1fr;
  }

  .puzzle-board {
    max-width: 100%;
  }
}