:root {
  --bg-primary: #0f1712;
  --bg-secondary: #17261e;
  --bg-card: #1f3328;
  --text-primary: #f1f5f9;
  --text-muted: #94a3b8;
  --accent-green: #10b981;
  --accent-light: #34d399;
  --accent-gold: #fbbf24;
  --danger-color: #ef4444;
  --node-bg: #22382c;
  --node-border: #3b5c49;
  --edge-color: #2e4939;
  --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --border-radius: 12px;
  --safe-top: env(safe-area-inset-top, 0px);
  --safe-bottom: env(safe-area-inset-bottom, 0px);
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  -webkit-tap-highlight-color: transparent;
}

html, body {
  width: 100%;
  height: 100%;
  overflow: hidden;
  background-color: var(--bg-primary);
  color: var(--text-primary);
  font-family: var(--font-family);
  user-select: none;
  -webkit-user-select: none;
}

.app-container {
  display: flex;
  flex-direction: column;
  height: 100%;
  max-width: 600px;
  margin: 0 auto;
  padding: var(--safe-top) 16px var(--safe-bottom) 16px;
  position: relative;
}

/* Header */
.app-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 0 8px 0;
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.icon-btn {
  background: transparent;
  border: none;
  color: var(--text-primary);
  cursor: pointer;
  padding: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 8px;
  transition: background 0.2s ease;
}

.icon-btn:hover {
  background: rgba(255, 255, 255, 0.1);
}

.games-btn {
  background: var(--bg-secondary);
  border: 1px solid rgba(255, 255, 255, 0.08);
  color: var(--text-primary);
  cursor: pointer;
  padding: 6px 12px;
  display: flex;
  align-items: center;
  gap: 6px;
  border-radius: 20px;
  font-size: 0.85rem;
  font-weight: 600;
  transition: background 0.2s ease, border-color 0.2s ease;
}

.games-btn:hover {
  background: rgba(255, 255, 255, 0.12);
  border-color: rgba(255, 255, 255, 0.2);
}

.header-titles {
  text-align: center;
}

.logo {
  font-size: 1.1rem;
  font-weight: 800;
  letter-spacing: 2px;
  color: var(--accent-light);
}

.puzzle-title {
  font-size: 0.85rem;
  color: var(--text-muted);
  cursor: pointer;
  transition: color 0.2s ease;
}

.puzzle-title:hover {
  color: var(--accent-light);
}

.timer-box {
  background: var(--bg-secondary);
  padding: 6px 12px;
  border-radius: 20px;
  border: 1px solid rgba(255, 255, 255, 0.08);
}

.timer-text {
  font-family: monospace;
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--accent-gold);
}

/* Word Preview & Action Bar */
.word-preview-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 48px;
  padding: 4px 8px;
  margin: 8px 0;
  background: var(--bg-secondary);
  border-radius: var(--border-radius);
  border: 1px solid rgba(255, 255, 255, 0.05);
}

.word-preview-text {
  font-size: 1.25rem;
  font-weight: 700;
  letter-spacing: 3px;
  color: var(--text-primary);
  min-height: 28px;
  display: flex;
  align-items: center;
  padding-left: 8px;
}

.word-actions {
  display: flex;
  gap: 8px;
}

.action-btn {
  border: none;
  padding: 8px 14px;
  border-radius: 8px;
  font-size: 0.85rem;
  font-weight: 600;
  cursor: pointer;
  transition: transform 0.1s ease, background 0.2s ease;
}

.action-btn:active {
  transform: scale(0.96);
}

.submit-btn {
  background: var(--accent-green);
  color: #064e3b;
}

.submit-btn:hover {
  background: var(--accent-light);
}

.clear-btn {
  background: rgba(255, 255, 255, 0.1);
  color: var(--text-muted);
}

.clear-btn:hover {
  background: rgba(255, 255, 255, 0.18);
  color: var(--text-primary);
}

/* Board Wrapper & Container */
.board-wrapper {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 0;
  padding: 8px 0;
}

.board-container {
  width: 100%;
  max-width: 480px;
  aspect-ratio: 1 / 1;
  touch-action: none;
  position: relative;
  border-radius: 16px;
  background: radial-gradient(circle, #1a2c22 0%, #122018 100%);
  box-shadow: inset 0 2px 10px rgba(0, 0, 0, 0.5), 0 8px 24px rgba(0, 0, 0, 0.4);
}

#game-board {
  width: 100%;
  height: 100%;
  display: block;
}

/* SVG Node and Edge Styling */
.edge-line {
  stroke: var(--edge-color);
  stroke-width: 12px;
  stroke-linecap: round;
  transition: opacity 0.4s ease, stroke 0.2s ease;
}

.drag-line {
  stroke: var(--accent-light);
  stroke-width: 14px;
  stroke-linecap: round;
  stroke-linejoin: round;
  fill: none;
  opacity: 0.9;
  pointer-events: none;
}

.node-group {
  cursor: pointer;
  transform-origin: center;
  transition: opacity 0.4s ease, transform 0.4s ease;
}

.node-circle {
  fill: var(--node-bg);
  stroke: var(--node-border);
  stroke-width: 6px;
  transition: fill 0.2s ease, stroke 0.2s ease, transform 0.2s ease;
}

.node-text {
  fill: var(--text-primary);
  font-size: 38px;
  font-weight: 800;
  text-anchor: middle;
  dominant-baseline: central;
  pointer-events: none;
  font-family: var(--font-family);
}

/* Node Highlight & Selected States */
.node-group.selected .node-circle {
  fill: var(--accent-green);
  stroke: var(--accent-light);
  filter: drop-shadow(0 0 10px rgba(52, 211, 153, 0.6));
}

.node-group.selected .node-text {
  fill: #064e3b;
}

/* Node & Edge Collapse Animation */
.node-group.pruned {
  opacity: 0;
  transform: scale(0);
  pointer-events: none;
}

.edge-line.pruned {
  opacity: 0;
  pointer-events: none;
}

/* Shake Animation for Invalid Submission */
@keyframes shake-anim {
  0%, 100% { transform: translateX(0); }
  20%, 60% { transform: translateX(-8px); }
  40%, 80% { transform: translateX(8px); }
}

.shake {
  animation: shake-anim 0.35s ease-in-out;
  border: 1px solid var(--danger-color) !important;
}

/* Discovered Words Tray */
.discovered-tray-wrapper {
  padding: 8px 0 12px 0;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
}

.tray-header {
  margin-bottom: 6px;
}

.tray-label {
  font-size: 0.8rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 1px;
  color: var(--text-muted);
}

.discovered-words-list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  min-height: 38px;
  max-height: 80px;
  overflow-y: auto;
}

.word-chip {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 4px 10px;
  background: var(--bg-card);
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: 16px;
  font-size: 0.85rem;
  font-weight: 700;
  letter-spacing: 1px;
  color: var(--text-primary);
  animation: chip-appear 0.3s cubic-bezier(0.34, 1.56, 0.64, 1);
}

.word-chip.star-chip {
  border-color: var(--accent-gold);
  color: #fef08a;
  background: #2b2513;
}

.chip-star {
  color: var(--accent-gold);
  font-size: 0.85rem;
}

@keyframes chip-appear {
  0% { transform: scale(0.6); opacity: 0; }
  100% { transform: scale(1); opacity: 1; }
}

/* Modals & Backdrop */
.modal-backdrop {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.75);
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 20px;
  z-index: 100;
  opacity: 1;
  transition: opacity 0.25s ease;
}

.modal-backdrop.hidden {
  opacity: 0;
  pointer-events: none;
}

/* Drawer */
.drawer-panel {
  background: var(--bg-secondary);
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: 16px;
  width: 100%;
  max-width: 400px;
  max-height: 80vh;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  box-shadow: 0 16px 36px rgba(0, 0, 0, 0.6);
}

.drawer-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px 20px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.drawer-header h2 {
  font-size: 1.1rem;
}

.puzzle-list-container {
  padding: 12px;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.puzzle-item-btn {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  padding: 12px 16px;
  background: var(--bg-card);
  border: 1px solid rgba(255, 255, 255, 0.05);
  border-radius: var(--border-radius);
  color: var(--text-primary);
  cursor: pointer;
  text-align: left;
  transition: background 0.2s ease, border-color 0.2s ease;
}

.puzzle-item-btn:hover {
  background: #253d30;
  border-color: rgba(255, 255, 255, 0.15);
}

.puzzle-item-btn.active {
  border-color: var(--accent-green);
  background: #193828;
}

.item-main {
  display: flex;
  flex-direction: column;
}

.item-title {
  font-weight: 700;
  font-size: 0.95rem;
}

.item-author {
  font-size: 0.75rem;
  color: var(--text-muted);
}

.item-status {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 0.8rem;
  font-weight: 600;
}

.completed-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 8px;
  border-radius: 12px;
  background: rgba(16, 185, 129, 0.15);
  border: 1px solid rgba(16, 185, 129, 0.3);
  color: var(--accent-light);
}

.green-checkmark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--accent-green);
  color: #064e3b;
  font-size: 11px;
  font-weight: 900;
  line-height: 1;
}

.best-time {
  font-family: monospace;
  font-size: 0.8rem;
  color: var(--text-primary);
}

/* Victory Card */
.victory-card {
  background: var(--bg-secondary);
  border: 1px solid rgba(255, 255, 255, 0.15);
  border-radius: 20px;
  width: 100%;
  max-width: 380px;
  padding: 24px;
  text-align: center;
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.7);
  animation: card-pop 0.35s cubic-bezier(0.34, 1.56, 0.64, 1);
}

@keyframes card-pop {
  0% { transform: scale(0.85); opacity: 0; }
  100% { transform: scale(1); opacity: 1; }
}

.victory-icon {
  font-size: 2.5rem;
  color: var(--accent-gold);
  margin-bottom: 8px;
}

.victory-card h2 {
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--text-primary);
  margin-bottom: 4px;
}

.victory-subtitle {
  color: var(--text-muted);
  font-size: 0.9rem;
  margin-bottom: 20px;
}

.stats-row {
  display: flex;
  gap: 12px;
  margin-bottom: 20px;
}

.stat-box {
  flex: 1;
  background: var(--bg-card);
  padding: 12px;
  border-radius: var(--border-radius);
  border: 1px solid rgba(255, 255, 255, 0.05);
}

.stat-label {
  display: block;
  font-size: 0.75rem;
  text-transform: uppercase;
  color: var(--text-muted);
  margin-bottom: 4px;
}

.stat-value {
  font-size: 1.25rem;
  font-weight: 700;
  font-family: monospace;
  color: var(--accent-gold);
}

.victory-words-review {
  margin-bottom: 24px;
  text-align: left;
}

.victory-words-review h3 {
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 1px;
  color: var(--text-muted);
  margin-bottom: 8px;
}

.victory-words-list {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  max-height: 100px;
  overflow-y: auto;
}

.no-more-games-banner {
  background: rgba(239, 68, 68, 0.15);
  border: 1px solid rgba(239, 68, 68, 0.35);
  color: #fca5a5;
  padding: 10px 14px;
  border-radius: 10px;
  font-size: 0.85rem;
  font-weight: 600;
  margin-bottom: 16px;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  animation: banner-appear 0.3s ease;
}

.no-more-games-banner.hidden {
  display: none;
}

@keyframes banner-appear {
  0% {
    opacity: 0;
    transform: translateY(-4px);
  }
  100% {
    opacity: 1;
    transform: translateY(0);
  }
}

.victory-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.primary-btn {
  flex: 1 1 100%;
  padding: 12px;
  background: var(--accent-green);
  color: #064e3b;
  border: none;
  border-radius: 10px;
  font-weight: 700;
  cursor: pointer;
  transition: background 0.2s ease;
}

.primary-btn:hover {
  background: var(--accent-light);
}

.secondary-btn {
  flex: 1 1 calc(50% - 5px);
  padding: 12px;
  background: rgba(255, 255, 255, 0.1);
  color: var(--text-primary);
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: 10px;
  font-weight: 600;
  cursor: pointer;
  transition: background 0.2s ease, opacity 0.2s ease;
}

.secondary-btn:hover {
  background: rgba(255, 255, 255, 0.18);
}

.secondary-btn:disabled,
.primary-btn:disabled {
  opacity: 0.45;
  cursor: not-allowed;
  pointer-events: none;
}

/* Toast Notification */
.toast-container {
  position: fixed;
  bottom: 24px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  z-index: 200;
  pointer-events: none;
}

.toast {
  background: var(--bg-card);
  color: var(--text-primary);
  border: 1px solid rgba(255, 255, 255, 0.15);
  padding: 10px 18px;
  border-radius: 20px;
  font-size: 0.85rem;
  font-weight: 600;
  box-shadow: 0 8px 20px rgba(0, 0, 0, 0.6);
  opacity: 0;
  transform: translateY(10px);
  transition: opacity 0.25s ease, transform 0.25s ease;
  pointer-events: auto;
}

.toast.show {
  opacity: 1;
  transform: translateY(0);
}

.toast.toast-warning {
  border-color: rgba(251, 191, 36, 0.4);
  color: var(--accent-gold);
}