:root {
  /* Theme Light */
  --bg-gradient: #f1f5f9;
  --card-bg: #ffffff;
  --card-border: #cbd5e1;
  --card-shadow: none;
  --text-primary: #0f172a;
  --text-secondary: #475569;
  --text-muted: #64748b;
  --accent-primary: #6366f1;
  --accent-hover: #4f46e5;
  --accent-light: #e0e7ff;
  --success: #10b981;
  --success-light: #d1fae5;
  --error: #ef4444;
  --error-light: #fee2e2;
  --panel-active-bg: #f8fafc;
  --border-radius: 0px;
  --transition-speed: 0.15s;
}

body.dark-mode {
  /* Theme Dark */
  --bg-gradient: #0f172a;
  --card-bg: #1e293b;
  --card-border: #334155;
  --card-shadow: none;
  --text-primary: #f8fafc;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  --accent-primary: #818cf8;
  --accent-hover: #6366f1;
  --accent-light: rgba(99, 102, 241, 0.15);
  --success: #34d399;
  --success-light: rgba(52, 211, 153, 0.1);
  --error: #f87171;
  --error-light: rgba(248, 113, 113, 0.1);
  --panel-active-bg: #0f172a;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  font-family: 'Outfit', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  border-radius: 0 !important;
  box-shadow: none !important;
  backdrop-filter: none !important;
}

body {
  min-height: 100vh;
  background: var(--bg-gradient);
  color: var(--text-primary);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: space-between;
  padding: 1rem;
  overflow-x: hidden;
  transition: background var(--transition-speed) ease, color var(--transition-speed) ease;
}

/* Background grid decoration (opacity reduced for cleaner flat look) */
.background-decor {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-image: linear-gradient(rgba(99, 102, 241, 0.02) 1px, transparent 1px),
                    linear-gradient(90deg, rgba(99, 102, 241, 0.02) 1px, transparent 1px);
  background-size: 40px 40px;
  pointer-events: none;
  z-index: -1;
}

/* HEADER */
.app-header {
  width: 100%;
  max-width: 1200px;
  display: flex;
  flex-direction: column;
  gap: 1rem;
  align-items: center;
  justify-content: space-between;
  padding: 1rem 0;
  background: transparent;
  border: none;
  margin-bottom: 1.5rem;
}

@media(min-width: 768px) {
  .app-header {
    flex-direction: row;
  }
}

.header-logo {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.logo-icon {
  font-size: 2.25rem;
}

.logo-text h1 {
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--text-primary);
}

.logo-text p {
  font-size: 0.875rem;
  color: var(--text-secondary);
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 1rem;
}

/* TABS */
.mode-tabs {
  display: flex;
  background: var(--panel-active-bg);
  padding: 4px;
  border-radius: 12px;
  border: 1px solid var(--card-border);
}

.tab-btn {
  background: transparent;
  border: none;
  color: var(--text-secondary);
  padding: 8px 16px;
  border-radius: 8px;
  font-size: 0.9rem;
  font-weight: 600;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 6px;
  transition: all var(--transition-speed) ease;
}

.tab-btn:hover {
  color: var(--text-primary);
}

.tab-btn.active {
  background: var(--card-bg);
  color: var(--accent-primary);
  box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.05);
}

.theme-toggle-btn {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  color: var(--text-primary);
  width: 40px;
  height: 40px;
  border-radius: 10px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: var(--card-shadow);
  transition: all var(--transition-speed) ease;
}

.theme-toggle-btn:hover {
  border-color: var(--accent-primary);
}

/* MAIN APP CONTAINER */
.app-container {
  width: 100%;
  max-width: 1200px;
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.5rem;
  flex-grow: 1;
  margin-bottom: 1.5rem;
}

@media(min-width: 900px) {
  .app-container {
    grid-template-columns: 450px 1fr;
  }
}

/* CARDS */
.card {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  backdrop-filter: blur(12px);
  border-radius: var(--border-radius);
  box-shadow: var(--card-shadow);
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
  height: fit-content;
}

/* PANELS */
.panel-content {
  display: none;
  flex-direction: column;
  gap: 1.25rem;
}

.panel-content.active {
  display: flex;
}

.section-title {
  font-size: 1.25rem;
  font-weight: 700;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.panel-desc {
  font-size: 0.875rem;
  color: var(--text-secondary);
  line-height: 1.4;
}

/* CONTROLS & OPTIONS */
.difficulty-section, .options-section {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.control-label {
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--text-secondary);
}

.difficulty-selector {
  display: flex;
  gap: 6px;
  width: 100%;
}

.diff-btn {
  flex: 1;
  background: var(--panel-active-bg);
  border: 1px solid var(--card-border);
  color: var(--text-secondary);
  padding: 8px;
  border-radius: 8px;
  cursor: pointer;
  font-weight: 600;
  font-size: 0.85rem;
  transition: all var(--transition-speed) ease;
}

.diff-btn:hover {
  border-color: var(--accent-primary);
  color: var(--text-primary);
}

.diff-btn.active {
  background: var(--accent-primary);
  border-color: var(--accent-primary);
  color: white;
  box-shadow: 0 4px 10px -2px var(--accent-light);
}

/* CHECKBOX */
.checkbox-container {
  display: flex;
  align-items: center;
  position: relative;
  padding-left: 28px;
  cursor: pointer;
  font-size: 0.85rem;
  color: var(--text-secondary);
  user-select: none;
}

.checkbox-container input {
  position: absolute;
  opacity: 0;
  cursor: pointer;
  height: 0;
  width: 0;
}

.checkmark {
  position: absolute;
  top: 0;
  left: 0;
  height: 18px;
  width: 18px;
  background-color: var(--panel-active-bg);
  border: 1px solid var(--card-border);
  border-radius: 4px;
  transition: all var(--transition-speed) ease;
}

.checkbox-container:hover input ~ .checkmark {
  border-color: var(--accent-primary);
}

.checkbox-container input:checked ~ .checkmark {
  background-color: var(--accent-primary);
  border-color: var(--accent-primary);
}

.checkmark:after {
  content: "";
  position: absolute;
  display: none;
}

.checkbox-container input:checked ~ .checkmark:after {
  display: block;
}

.checkbox-container .checkmark:after {
  left: 5px;
  top: 2px;
  width: 5px;
  height: 9px;
  border: solid white;
  border-width: 0 2px 2px 0;
  transform: rotate(45deg);
}

/* EXERCISE CARD */
.exercise-card {
  background: var(--panel-active-bg);
  border: 1px solid var(--card-border);
  border-radius: 12px;
  padding: 1.25rem;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.exercise-question {
  font-size: 1.1rem;
  font-weight: 700;
  text-align: center;
  color: var(--text-primary);
}

.answer-row {
  display: flex;
  gap: 10px;
  align-items: center;
  justify-content: center;
}

.answer-input {
  width: 100px;
  height: 50px;
  border-radius: 10px;
  border: 2px solid var(--card-border);
  background: var(--card-bg);
  color: var(--text-primary);
  font-size: 1.5rem;
  font-weight: 700;
  text-align: center;
  outline: none;
  transition: border-color var(--transition-speed) ease;
}

.answer-input:focus {
  border-color: var(--accent-primary);
  box-shadow: 0 0 0 3px var(--accent-light);
}

.answer-input::-webkit-outer-spin-button,
.answer-input::-webkit-inner-spin-button {
  -webkit-appearance: none;
  margin: 0;
}

/* BUTTONS */
.btn {
  padding: 12px 20px;
  border-radius: 10px;
  font-weight: 600;
  font-size: 0.95rem;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  border: none;
  transition: all var(--transition-speed) ease;
}

.btn:active {
  transform: scale(0.98);
}

.btn-primary {
  background: var(--accent-primary);
  color: white;
}

.btn-primary:hover {
  background: var(--accent-hover);
  box-shadow: 0 6px 15px -3px var(--accent-light);
}

.btn-secondary {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  color: var(--text-primary);
}

.btn-secondary:hover {
  border-color: var(--accent-primary);
  background: var(--panel-active-bg);
}

.btn-muted {
  background: transparent;
  border: 1px solid var(--card-border);
  color: var(--text-secondary);
}

.btn-muted:hover {
  color: var(--text-primary);
  border-color: var(--text-secondary);
}

.btn-danger {
  background: var(--error-light);
  color: var(--error);
  border: 1px solid rgba(239, 68, 68, 0.2);
}

.btn-danger:hover {
  background: var(--error);
  color: white;
}

.btn-success {
  background: var(--success-light);
  color: var(--success);
  border: 1px solid rgba(16, 185, 129, 0.2);
}

.btn-success:hover {
  background: var(--success);
  color: white;
}

.exercise-actions {
  display: flex;
  gap: 10px;
  margin-top: 0.5rem;
}

.exercise-actions .btn {
  flex: 1;
}

/* FEEDBACK BOX */
.feedback-box {
  padding: 12px;
  border-radius: 8px;
  font-size: 0.9rem;
  font-weight: 600;
  text-align: center;
  display: none;
  animation: slideIn 0.3s cubic-bezier(0.16, 1, 0.3, 1);
}

.feedback-box.success {
  display: block;
  background: var(--success-light);
  color: var(--success);
  border: 1px solid rgba(16, 185, 129, 0.2);
  animation: popSuccess 0.4s ease;
}

.feedback-box.error {
  display: block;
  background: var(--error-light);
  color: var(--error);
  border: 1px solid rgba(239, 68, 68, 0.2);
  animation: shake 0.4s ease;
}

.feedback-box.info-message {
  display: block;
  background: var(--accent-light);
  color: var(--accent-primary);
  border: 1px solid rgba(99, 102, 241, 0.2);
}

/* GRILLE DE CORRECTION (VUE DE DESSUS) */
.correction-container {
  margin-top: 14px;
  padding-top: 12px;
  border-top: 1px dashed rgba(239, 68, 68, 0.3);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 10px;
}

.correction-title {
  font-size: 0.85rem;
  font-weight: 700;
  margin: 0;
  color: var(--error);
}

.correction-table {
  border-collapse: separate;
  border-spacing: 5px;
  margin: 0 auto;
}

.correction-cell {
  width: 32px;
  height: 32px;
  font-size: 0.95rem;
  font-weight: 700;
  text-align: center;
  vertical-align: middle;
  border-radius: 6px;
  transition: all 0.2s ease;
}

.correction-cell.has-cubes {
  background-color: var(--error);
  color: #ffffff;
  box-shadow: 0 2px 4px rgba(239, 68, 68, 0.2);
}

.correction-cell.empty {
  border: 1px dashed rgba(239, 68, 68, 0.4);
  color: rgba(239, 68, 68, 0.6);
}

/* SCORE CARD */
.score-card {
  display: flex;
  gap: 1rem;
}

.score-stat {
  flex: 1;
  background: var(--panel-active-bg);
  border: 1px solid var(--card-border);
  border-radius: 10px;
  padding: 8px 12px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
}

.score-label {
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--text-muted);
  text-transform: uppercase;
}

.score-value {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-top: 2px;
}

/* MODE CRÉATEUR SPECIFIC */
.settings-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
}

.setting-item {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.setting-item label {
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--text-secondary);
}

.setting-item input {
  height: 38px;
  border-radius: 6px;
  border: 1px solid var(--card-border);
  background: var(--panel-active-bg);
  color: var(--text-primary);
  padding: 0 10px;
  font-weight: 600;
  outline: none;
}

.setting-item input:focus {
  border-color: var(--accent-primary);
}

.grid-editor-container {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
  background: var(--panel-active-bg);
  border: 1px solid var(--card-border);
  border-radius: 12px;
  padding: 1rem;
}

#tableau {
  background: var(--card-bg);
  border-radius: 8px;
  box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.05);
  cursor: pointer;
  max-width: 100%;
}

.editor-totals {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.95rem;
}

.total-label {
  font-weight: 600;
  color: var(--text-secondary);
}

.total-value {
  font-weight: 800;
  font-size: 1.2rem;
  color: var(--accent-primary);
}

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

.creator-actions .btn {
  flex: 1;
}

/* ROTATION PAD (D-PAD) */
.rotation-section {
  border-top: 1px solid var(--card-border);
  padding-top: 1.25rem;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.rotation-pad {
  display: flex;
  gap: 8px;
  width: 100%;
}

.rot-btn {
  flex: 1;
  height: 40px;
  border-radius: 8px;
  background: var(--panel-active-bg);
  border: 1px solid var(--card-border);
  color: var(--text-secondary);
  font-weight: 600;
  font-size: 0.85rem;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  transition: all var(--transition-speed) ease;
}

.rot-btn:hover {
  background: var(--accent-light);
  border-color: var(--accent-primary);
  color: var(--text-primary);
}

.rot-icon {
  font-size: 1.1rem;
}

/* VIEWER PANEL (RIGHT) */
.viewer-panel {
  display: flex;
  flex-direction: column;
  align-items: stretch;
  justify-content: flex-start;
  flex-grow: 1;
  min-height: 450px;
}

.viewer-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 10px;
  border-bottom: 1px solid var(--card-border);
  padding-bottom: 1rem;
}

.view-indicator {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text-secondary);
}

.indicator-dot {
  width: 8px;
  height: 8px;
  background-color: var(--accent-primary);
  border-radius: 50%;
  box-shadow: 0 0 8px var(--accent-primary);
}



.canvas-wrapper {
  display: flex;
  justify-content: center;
  align-items: center;
  padding: 1.5rem;
  background: var(--panel-active-bg);
  border-radius: 12px;
  border: 1px solid var(--card-border);
  flex-grow: 1;
  min-height: 300px;
  position: relative;
}

#canvas-dessin {
  background: transparent;
  cursor: grab;
  outline: none;
  max-width: 100%;
}

#canvas-dessin:active {
  cursor: grabbing;
}

/* HELP ACCORDION / GRID OVERLAY */
.help-grid-overlay {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: 10px;
  padding: 1rem;
  margin-top: 1rem;
  display: flex;
  flex-direction: column;
  gap: 8px;
  animation: slideIn 0.3s cubic-bezier(0.16, 1, 0.3, 1);
}

.help-grid-overlay.hidden {
  display: none !important;
}

.help-grid-overlay h4 {
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--accent-primary);
}

.help-grid-overlay p {
  font-size: 0.8rem;
  color: var(--text-secondary);
}

.help-table {
  border-collapse: collapse;
  margin: 8px auto 0 auto;
  min-width: 150px;
}

.help-table td {
  border: 1px solid var(--card-border);
  width: 35px;
  height: 35px;
  text-align: center;
  font-weight: 700;
  font-size: 1rem;
  background: var(--panel-active-bg);
  color: var(--text-primary);
}

.keyboard-tips {
  font-size: 0.775rem;
  color: var(--text-muted);
  text-align: center;
  line-height: 1.4;
  padding-top: 0.5rem;
}

/* FOOTER */
footer.app-footer {
  width: 100%;
  max-width: 1200px;
  text-align: center;
  padding: 1rem;
  font-size: 0.8rem;
  color: var(--text-muted);
  border-top: 1px solid var(--card-border);
  margin-top: 1rem;
}

/* ANIMATIONS */
@keyframes slideIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

@keyframes shake {
  0%, 100% { transform: translateX(0); }
  20%, 60% { transform: translateX(-6px); }
  40%, 80% { transform: translateX(6px); }
}

@keyframes popSuccess {
  0% { opacity: 0.8; }
  100% { opacity: 1; }
}

/* SUIVI BADGE */
.suivi-badge {
  background: var(--accent-light);
  color: var(--accent-primary);
  padding: 10px 14px;
  font-weight: 700;
  font-size: 0.95rem;
  text-align: center;
  border: 1px solid var(--accent-primary);
  width: 100%;
  margin-top: 5px;
}