/* CSS Variables for Theming */
:root {
  /* Primary Colors */
  --primary-color: #4a90e2;
  --primary-hover: #3a7bc8;
  --primary-light: #e8f2fc;
  
  /* Secondary Colors */
  --secondary-color: #6c757d;
  --secondary-hover: #5a6268;
  --secondary-light: #f8f9fa;
  
  /* Status Colors */
  --success-color: #28a745;
  --success-light: #d4edda;
  --danger-color: #dc3545;
  --danger-light: #f8d7da;
  --warning-color: #ffc107;
  --warning-light: #fff3cd;
  
  /* Neutral Colors */
  --bg-color: #ffffff;
  --bg-secondary: #f8f9fa;
  --bg-tertiary: #e9ecef;
  --text-color: #212529;
  --text-secondary: #6c757d;
  --text-light: #adb5bd;
  --border-color: #dee2e6;
  --shadow-color: rgba(0, 0, 0, 0.1);
  
  /* Spacing */
  --spacing-xs: 0.25rem;
  --spacing-sm: 0.5rem;
  --spacing-md: 1rem;
  --spacing-lg: 1.5rem;
  --spacing-xl: 2rem;
  --spacing-xxl: 3rem;
  
  /* Border Radius */
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --radius-full: 50%;
  
  /* Typography */
  --font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
  --font-size-xs: 0.75rem;
  --font-size-sm: 0.875rem;
  --font-size-md: 1rem;
  --font-size-lg: 1.125rem;
  --font-size-xl: 1.5rem;
  --font-size-xxl: 2rem;
  --font-size-hero: 3rem;
  
  /* Touch Target */
  --touch-target: 48px;
  
  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-normal: 300ms ease;
  --transition-slow: 500ms ease;
  
  /* Z-index layers */
  --z-base: 1;
  --z-dropdown: 10;
  --z-modal: 100;
  --z-toast: 1000;
}

/* Reset & Base Styles */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  -webkit-tap-highlight-color: transparent;
}

body {
  font-family: var(--font-family);
  font-size: var(--font-size-md);
  line-height: 1.5;
  color: var(--text-color);
  background-color: var(--bg-color);
  min-height: 100vh;
  overflow-x: hidden;
}

/* App Container */
.app-container {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
  max-width: 600px;
  margin: 0 auto;
  position: relative;
}

/* Header */
.app-header {
  background-color: var(--primary-color);
  color: white;
  padding: var(--spacing-md) var(--spacing-lg);
  position: sticky;
  top: 0;
  z-index: var(--z-base);
  box-shadow: 0 2px 4px var(--shadow-color);
}

.header-content {
  display: flex;
  align-items: center;
  justify-content: space-between;
  max-width: 600px;
  margin: 0 auto;
}

.header-btn,
.header-btn-placeholder {
  width: 44px;
  height: 44px;
  border: none;
  border-radius: var(--radius-full);
  background: transparent;
  color: white;
  font-size: var(--font-size-xl);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background-color var(--transition-fast);
  flex-shrink: 0;
  text-decoration: none;
}

.app-title {
  font-size: var(--font-size-xl);
  font-weight: 700;
  flex: 1;
  text-align: center;
  margin: 0;
  letter-spacing: -0.5px;
}

.header-btn {
  width: 44px;
  height: 44px;
  border: none;
  border-radius: var(--radius-full);
  background: transparent;
  color: white;
  font-size: var(--font-size-xl);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background-color var(--transition-fast);
  flex-shrink: 0;
}

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

.header-btn:active {
  background-color: rgba(255, 255, 255, 0.2);
}

.add-btn {
  font-size: 28px;
  line-height: 1;
  font-weight: 300;
}

/* Main Content */
.main-content {
  flex: 1;
  padding: var(--spacing-md);
}

/* Views */
.view {
  display: none;
  animation: fadeIn var(--transition-normal);
}

.view.active {
  display: block;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}

/* View Headers */
.view-header {
  margin-bottom: var(--spacing-lg);
}

.view-header h2 {
  font-size: var(--font-size-xl);
  color: var(--text-color);
  margin-bottom: var(--spacing-xs);
}

.subtitle {
  color: var(--text-secondary);
  font-size: var(--font-size-sm);
}

/* Schedule List View */
.schedule-list {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-md);
}

.schedule-item {
  background: var(--bg-color);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: var(--spacing-md);
  display: flex;
  flex-direction: column;
  gap: var(--spacing-md);
  box-shadow: 0 2px 8px var(--shadow-color);
  transition: transform var(--transition-fast), box-shadow var(--transition-fast);
}

.schedule-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  position: relative;
}

.schedule-info {
  flex: 1;
  min-width: 0;
}

.schedule-item:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 12px var(--shadow-color);
}

.schedule-info {
  flex: 1;
}

.schedule-name {
  font-size: var(--font-size-lg);
  font-weight: 600;
  margin-bottom: var(--spacing-xs);
}

.schedule-meta {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  color: var(--text-secondary);
  font-size: var(--font-size-sm);
}

.meta-separator {
  color: var(--text-light);
}

.schedule-actions {
  position: relative;
  flex-shrink: 0;
}

.schedule-menu-btn {
  width: 40px;
  height: 40px;
  border: none;
  border-radius: var(--radius-md);
  background: var(--bg-secondary);
  color: var(--text-secondary);
  font-size: var(--font-size-lg);
  cursor: pointer;
  transition: background-color var(--transition-fast);
}

.schedule-menu-btn:hover {
  background: var(--bg-tertiary);
}

.schedule-menu {
  position: absolute;
  top: 100%;
  right: 0;
  margin-top: 4px;
  background: var(--bg-color);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  box-shadow: 0 4px 16px var(--shadow-color);
  z-index: var(--z-dropdown);
  display: none;
  min-width: 160px;
  overflow: hidden;
}

.schedule-menu.open {
  display: block;
}

.menu-item {
  width: 100%;
  padding: var(--spacing-md) var(--spacing-lg);
  border: none;
  background: transparent;
  text-align: left;
  cursor: pointer;
  transition: background-color var(--transition-fast);
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
  color: var(--text-color);
  font-size: var(--font-size-md);
}

.menu-item:hover {
  background: var(--bg-secondary);
}

.menu-item.delete-btn {
  color: var(--danger-color);
}

.start-workout-btn {
  width: 100%;
  padding: var(--spacing-md);
  font-weight: 600;
}

/* Empty State */
.empty-state, .loading-state, .error-state {
  text-align: center;
  padding: var(--spacing-xxl);
}

.empty-icon {
  font-size: 4rem;
  margin-bottom: var(--spacing-md);
}

.empty-state h3 {
  font-size: var(--font-size-xl);
  margin-bottom: var(--spacing-sm);
}

.empty-state p {
  color: var(--text-secondary);
  margin-bottom: var(--spacing-lg);
}

/* Loading State */
.loading-state {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--spacing-md);
}

.spinner {
  width: 40px;
  height: 40px;
  border: 4px solid var(--bg-tertiary);
  border-top-color: var(--primary-color);
  border-radius: var(--radius-full);
  animation: spin 1s linear infinite;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

/* Error State */
.error-state {
  color: var(--danger-color);
}

.error-icon {
  font-size: 3rem;
  margin-bottom: var(--spacing-md);
}

.error-state h3 {
  color: var(--danger-color);
  margin-bottom: var(--spacing-sm);
}

/* Builder View */
.builder-container {
  max-width: 500px;
  margin: 0 auto;
}

.schedule-name-section {
  margin-bottom: var(--spacing-lg);
}

.input-label {
  display: block;
  font-weight: 600;
  margin-bottom: var(--spacing-sm);
  color: var(--text-color);
}

.schedule-name-input {
  width: 100%;
  padding: var(--spacing-md);
  border: 2px solid var(--border-color);
  border-radius: var(--radius-md);
  font-size: var(--font-size-md);
  transition: border-color var(--transition-fast);
}

.schedule-name-input:focus {
  outline: none;
  border-color: var(--primary-color);
}

.exercises-section {
  margin-bottom: var(--spacing-xl);
}

.section-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: var(--spacing-md);
}

.section-header h3 {
  font-size: var(--font-size-lg);
  font-weight: 600;
}

.section-header-actions {
  display: flex;
  gap: var(--spacing-sm);
}

.section-header-actions .secondary-btn {
  padding: var(--spacing-sm) var(--spacing-md);
  font-size: var(--font-size-sm);
  min-height: auto;
}

.exercises-list {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-md);
}

.exercise-item {
  background: var(--bg-color);
  border: 2px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: var(--spacing-md);
  display: flex;
  gap: var(--spacing-md);
  align-items: flex-start;
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.exercise-item.dragging {
  opacity: 0.5;
  border-color: var(--primary-color);
}

.exercise-item.drag-over {
  border-color: var(--primary-color);
  box-shadow: 0 0 0 2px var(--primary-light);
}

.exercise-drag-handle {
  width: 24px;
  height: 24px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-light);
  cursor: grab;
  user-select: none;
  font-size: var(--font-size-lg);
}

.exercise-drag-handle:active {
  cursor: grabbing;
}

.exercise-content {
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: var(--spacing-md);
}

.exercise-name-input {
  width: 100%;
  padding: var(--spacing-sm) var(--spacing-md);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  font-size: var(--font-size-md);
  transition: border-color var(--transition-fast);
}

.exercise-name-input:focus {
  outline: none;
  border-color: var(--primary-color);
}

.exercise-details {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--spacing-md);
}

.detail-group {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-xs);
}

.detail-label {
  font-size: var(--font-size-xs);
  color: var(--text-secondary);
  font-weight: 500;
}

.detail-input {
  width: 100%;
  padding: var(--spacing-sm);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  font-size: var(--font-size-md);
  text-align: center;
  transition: border-color var(--transition-fast);
}

.detail-input:focus {
  outline: none;
  border-color: var(--primary-color);
}

.exercise-remove-btn {
  width: 32px;
  height: 32px;
  border: none;
  border-radius: var(--radius-full);
  background: var(--danger-light);
  color: var(--danger-color);
  font-size: var(--font-size-lg);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background-color var(--transition-fast);
  flex-shrink: 0;
}

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

.exercises-empty {
  text-align: center;
  padding: var(--spacing-xl);
  color: var(--text-secondary);
  background: var(--bg-secondary);
  border-radius: var(--radius-lg);
  border: 2px dashed var(--border-color);
}

.builder-actions {
  padding-top: var(--spacing-lg);
  border-top: 1px solid var(--border-color);
}

.save-btn {
  width: 100%;
  padding: var(--spacing-lg);
  font-size: var(--font-size-lg);
  font-weight: 600;
}

.save-btn:disabled {
  background-color: var(--text-light);
  cursor: not-allowed;
}

/* Execution View */
.execution-container {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  min-height: calc(100vh - 180px);
  text-align: center;
  padding: var(--spacing-xl);
}

.exercise-info {
  margin-bottom: var(--spacing-xl);
}

.exercise-name {
  font-size: var(--font-size-xxl);
  font-weight: 700;
  margin-bottom: var(--spacing-sm);
  color: var(--primary-color);
}

.progress-info {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-md);
  font-size: var(--font-size-lg);
  color: var(--text-secondary);
}

.progress-separator {
  color: var(--text-light);
}

.timer-display {
  margin-bottom: var(--spacing-xl);
  display: none;
}

.timer-display.active {
  display: block;
  animation: pulse 1s infinite;
}

.timer-value {
  font-size: var(--font-size-hero);
  font-weight: 700;
  color: var(--warning-color);
  line-height: 1;
  margin-bottom: var(--spacing-sm);
}

.timer-label {
  font-size: var(--font-size-md);
  color: var(--text-secondary);
}

@keyframes pulse {
  0%, 100% { transform: scale(1); }
  50% { transform: scale(1.05); }
}

.workout-progress {
  width: 100%;
  max-width: 300px;
  margin-bottom: var(--spacing-xl);
}

.progress-bar {
  width: 100%;
  height: 8px;
  background: var(--bg-tertiary);
  border-radius: var(--radius-full);
  overflow: hidden;
  margin-bottom: var(--spacing-sm);
}

.progress-fill {
  height: 100%;
  background: var(--primary-color);
  border-radius: var(--radius-full);
  transition: width var(--transition-normal);
}

.progress-text {
  font-size: var(--font-size-sm);
  color: var(--text-secondary);
}

.main-action {
  margin-bottom: var(--spacing-xl);
}

.action-btn {
  width: 200px;
  height: 200px;
  border-radius: var(--radius-full);
  font-size: var(--font-size-xl);
  font-weight: 700;
  box-shadow: 0 8px 24px var(--shadow-color);
  transition: transform var(--transition-fast), box-shadow var(--transition-fast);
}

.action-btn:active {
  transform: scale(0.95);
  box-shadow: 0 4px 12px var(--shadow-color);
}

.action-btn.break-phase {
  background: var(--warning-color);
  color: var(--text-color);
}

.secondary-controls {
  display: flex;
  gap: var(--spacing-md);
  margin-bottom: var(--spacing-xl);
}

.control-btn {
  padding: var(--spacing-md) var(--spacing-lg);
  min-width: 100px;
}

.next-exercise {
  color: var(--text-secondary);
  font-size: var(--font-size-sm);
  opacity: 0.7;
}

.next-label {
  margin-bottom: var(--spacing-xs);
}

.next-name {
  font-weight: 600;
}

/* Complete View */
.complete-container {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  min-height: calc(100vh - 180px);
  text-align: center;
  padding: var(--spacing-xl);
}

.complete-icon {
  font-size: 5rem;
  margin-bottom: var(--spacing-lg);
  animation: bounce 1s infinite;
}

@keyframes bounce {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-20px); }
}

.complete-container h2 {
  font-size: var(--font-size-xxl);
  color: var(--success-color);
  margin-bottom: var(--spacing-sm);
}

.complete-message {
  color: var(--text-secondary);
  font-size: var(--font-size-lg);
  margin-bottom: var(--spacing-xl);
}

.complete-stats {
  display: flex;
  justify-content: center;
  gap: var(--spacing-xxl);
  margin-bottom: var(--spacing-xl);
}

.stat-item {
  display: flex;
  flex-direction: column;
  align-items: center;
}

.stat-value {
  font-size: var(--font-size-xl);
  font-weight: 700;
  color: var(--primary-color);
  line-height: 1.2;
}

.stat-label {
  font-size: var(--font-size-sm);
  color: var(--text-secondary);
}

.complete-actions {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-md);
  width: 100%;
  max-width: 300px;
}

.complete-actions button {
  width: 100%;
}



/* Modal */
.modal {
  position: fixed;
  inset: 0;
  z-index: var(--z-modal);
  display: none;
  align-items: center;
  justify-content: center;
  padding: var(--spacing-md);
}

.modal.open {
  display: flex;
}

.modal-overlay {
  position: absolute;
  inset: 0;
  background: rgba(0, 0, 0, 0.5);
  backdrop-filter: blur(2px);
}

.modal-content {
  position: relative;
  background: var(--bg-color);
  border-radius: var(--radius-lg);
  padding: var(--spacing-xl);
  max-width: 400px;
  width: 100%;
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.2);
}

.modal-title {
  font-size: var(--font-size-lg);
  margin-bottom: var(--spacing-md);
}

.modal-message {
  color: var(--text-secondary);
  margin-bottom: var(--spacing-xl);
  line-height: 1.6;
}

.modal-actions {
  display: flex;
  gap: var(--spacing-md);
  justify-content: flex-end;
}

.modal-btn {
  min-width: 100px;
}

/* Toast */
.toast {
  position: fixed;
  bottom: 80px;
  left: 50%;
  transform: translateX(-50%) translateY(100px);
  background: var(--text-color);
  color: white;
  padding: var(--spacing-md) var(--spacing-xl);
  border-radius: var(--radius-lg);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
  z-index: var(--z-toast);
  opacity: 0;
  transition: all var(--transition-normal);
}

.toast.show {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
}

.toast.success {
  background: var(--success-color);
}

.toast.error {
  background: var(--danger-color);
}

.toast.warning {
  background: var(--warning-color);
  color: var(--text-color);
}

/* Buttons */
.primary-btn {
  background: var(--primary-color);
  color: white;
  border: none;
  border-radius: var(--radius-md);
  padding: var(--spacing-md) var(--spacing-xl);
  font-size: var(--font-size-md);
  font-weight: 600;
  cursor: pointer;
  transition: background-color var(--transition-fast), transform var(--transition-fast);
  min-height: var(--touch-target);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-sm);
}

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

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

.secondary-btn {
  background: var(--bg-color);
  color: var(--text-color);
  border: 2px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: var(--spacing-md) var(--spacing-xl);
  font-size: var(--font-size-md);
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition-fast);
  min-height: var(--touch-target);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-sm);
}

.secondary-btn:hover {
  background: var(--bg-secondary);
  border-color: var(--text-secondary);
}

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

.secondary-btn.danger-btn {
  background: var(--danger-light);
  color: var(--danger-color);
  border-color: var(--danger-color);
}

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

/* Responsive Adjustments */
@media (max-width: 480px) {
  html {
    font-size: 14px;
  }
  
  .exercise-details {
    grid-template-columns: 1fr;
  }
  
  .detail-group {
    flex-direction: row;
    align-items: center;
    justify-content: space-between;
  }
  
  .detail-input {
    width: 80px;
  }
  
  .action-btn {
    width: 160px;
    height: 160px;
    font-size: var(--font-size-lg);
  }
  
  .secondary-controls {
    flex-direction: column;
  }
  
  .control-btn {
    width: 100%;
  }
}

@media (min-width: 768px) {
  .main-content {
    padding: var(--spacing-xl);
  }
  
  .exercise-details {
    grid-template-columns: repeat(3, 1fr);
  }
}

/* Dark Mode Support */
@media (prefers-color-scheme: dark) {
  :root {
    --bg-color: #1a1a1a;
    --bg-secondary: #2d2d2d;
    --bg-tertiary: #3d3d3d;
    --text-color: #ffffff;
    --text-secondary: #b0b0b0;
    --text-light: #808080;
    --border-color: #404040;
    --shadow-color: rgba(0, 0, 0, 0.3);
  }
  
  .modal-content,
  .schedule-item,
  .exercise-item,
  .schedule-menu {
    background: var(--bg-color);
    border-color: var(--border-color);
  }
  
  .exercises-empty {
    background: var(--bg-secondary);
    border-color: var(--border-color);
  }
  
  .menu-item {
    color: var(--text-color);
  }
  
  .menu-item:hover {
    background: var(--bg-tertiary);
  }
}

/* Print Styles */
@media print {
  .app-header,
  .app-footer,
  .schedule-actions,
  .builder-actions,
  .secondary-controls {
    display: none;
  }
  
  .schedule-item {
    break-inside: avoid;
    box-shadow: none;
    border: 1px solid #ccc;
  }
}