@import url("https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&display=swap");

/* CSS Variables for theming */
:root {
  --primary-color: #3b82f6;
  --primary-dark: #2563eb;
  --secondary-color: #8b5cf6;
  --success-color: #10b981;
  --danger-color: #ef4444;
  --warning-color: #f59e0b;
  --background: #f8fafc;
  --surface: #ffffff;
  --surface-hover: #f1f5f9;
  --border: #e2e8f0;
  --border-light: #f1f5f9;
  --text-primary: #1e293b;
  --text-secondary: #64748b;
  --text-muted: #94a3b8;
  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
  --shadow: 0 1px 3px 0 rgb(0 0 0 / 0.1), 0 1px 2px -1px rgb(0 0 0 / 0.1);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
  --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
  --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);
  --radius: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
}

/* Dark mode variables */
@media (prefers-color-scheme: dark) {
  :root {
    --background: #0f172a;
    --surface: #1e293b;
    --surface-hover: #334155;
    --border: #334155;
    --border-light: #475569;
    --text-primary: #f8fafc;
    --text-secondary: #cbd5e1;
    --text-muted: #94a3b8;
  }
}

/* Reset and base styles */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 50%, #f093fb 100%);
  min-height: 100vh;
  overflow: hidden;
  touch-action: none;
  color: var(--text-primary);
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

.app-container {
  display: flex;
  height: 100vh;
  background: var(--surface);
  border-radius: var(--radius-xl);
  margin: 8px;
  box-shadow: var(--shadow-xl);
  overflow: hidden;
  backdrop-filter: blur(20px);
}

/* Sidebar Styles */
.sidebar {
  width: 320px;
  background: var(--background);
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  overflow-y: auto;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.sidebar-header {
  padding: 24px 20px 16px;
  border-bottom: 1px solid var(--border-light);
  background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
}

.app-title {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 20px;
  font-weight: 700;
  color: white;
  margin: 0;
}

.title-icon {
  font-size: 24px;
  filter: drop-shadow(0 2px 4px rgba(0, 0, 0, 0.2));
}

.tool-group {
  margin: 16px;
  background: var(--surface);
  border-radius: var(--radius-lg);
  padding: 20px;
  box-shadow: var(--shadow);
  border: 1px solid var(--border-light);
  transition: all 0.2s ease;
}

.tool-group:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-1px);
}

.tool-group h3 {
  font-size: 14px;
  font-weight: 600;
  color: var(--text-secondary);
  margin-bottom: 16px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.tool-buttons {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 8px;
}

.tool-btn {
  background: var(--surface);
  border: 2px solid var(--border);
  border-radius: var(--radius);
  padding: 12px;
  cursor: pointer;
  transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 4px;
  min-height: 60px;
  position: relative;
  overflow: hidden;
}

.tool-btn::before {
  content: "";
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.2), transparent);
  transition: left 0.5s;
}

.tool-btn:hover::before {
  left: 100%;
}

.tool-btn:hover {
  border-color: var(--primary-color);
  background: var(--surface-hover);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.tool-btn.active {
  background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
  border-color: var(--primary-color);
  color: white;
  box-shadow: var(--shadow-lg);
}

.tool-icon {
  font-size: 20px;
  filter: drop-shadow(0 1px 2px rgba(0, 0, 0, 0.1));
}

.tool-label {
  font-size: 11px;
  font-weight: 500;
  opacity: 0.9;
}

/* Color Section */
.color-section {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.color-picker-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
}

.color-picker-item {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.color-picker-item label {
  font-size: 12px;
  font-weight: 500;
  color: var(--text-secondary);
}

.color-input-wrapper {
  position: relative;
  display: flex;
  align-items: center;
  gap: 8px;
}

.color-input {
  width: 100%;
  height: 40px;
  border: 2px solid var(--border);
  border-radius: var(--radius);
  cursor: pointer;
  background: none;
  transition: all 0.2s ease;
}

.color-input:hover {
  border-color: var(--primary-color);
  box-shadow: var(--shadow);
}

.color-preview {
  width: 24px;
  height: 24px;
  border-radius: 50%;
  border: 2px solid var(--border);
  box-shadow: var(--shadow-sm);
}

.fill-options {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.fill-mode-selector {
  display: flex;
  gap: 4px;
  background: var(--border-light);
  padding: 4px;
  border-radius: var(--radius);
}

.fill-mode-btn {
  flex: 1;
  background: transparent;
  border: none;
  padding: 8px;
  border-radius: calc(var(--radius) - 2px);
  cursor: pointer;
  transition: all 0.2s ease;
  font-size: 16px;
}

.fill-mode-btn:hover {
  background: var(--surface-hover);
}

.fill-mode-btn.active {
  background: var(--primary-color);
  color: white;
  box-shadow: var(--shadow);
}

.opacity-control {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.opacity-control label {
  font-size: 12px;
  font-weight: 500;
  color: var(--text-secondary);
}

.color-palette {
  margin-top: 8px;
}

.palette-colors {
  display: grid;
  grid-template-columns: repeat(6, 1fr);
  gap: 6px;
}

.palette-color {
  width: 32px;
  height: 32px;
  border-radius: var(--radius);
  cursor: pointer;
  transition: all 0.2s ease;
  border: 2px solid transparent;
  box-shadow: var(--shadow-sm);
}

.palette-color:hover {
  transform: scale(1.1);
  box-shadow: var(--shadow-md);
  border-color: var(--primary-color);
}

/* Brush Controls */
.brush-controls {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.slider-container {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.slider-container label {
  font-size: 12px;
  font-weight: 500;
  color: var(--text-secondary);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.slider {
  width: 100%;
  height: 6px;
  border-radius: 3px;
  background: var(--border-light);
  outline: none;
  cursor: pointer;
  -webkit-appearance: none;
  appearance: none;
  transition: all 0.2s ease;
}

.slider:hover {
  background: var(--border);
}

.slider::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
  cursor: pointer;
  border: 3px solid white;
  box-shadow: var(--shadow-md);
  transition: all 0.2s ease;
}

.slider::-webkit-slider-thumb:hover {
  transform: scale(1.2);
  box-shadow: var(--shadow-lg);
}

.slider::-moz-range-thumb {
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
  cursor: pointer;
  border: 3px solid white;
  box-shadow: var(--shadow-md);
  border: none;
}

.brush-preview {
  display: flex;
  justify-content: center;
  align-items: center;
  height: 60px;
  background: var(--border-light);
  border-radius: var(--radius);
  margin-top: 8px;
}

#brushPreviewCircle {
  background: var(--text-primary);
  border-radius: 50%;
  transition: all 0.2s ease;
  box-shadow: var(--shadow);
}

/* Action Grid */
.action-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px;
}

.action-btn {
  background: var(--surface);
  color: var(--text-primary);
  border: 2px solid var(--border);
  padding: 12px;
  border-radius: var(--radius);
  cursor: pointer;
  font-weight: 500;
  transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
  min-height: 60px;
  position: relative;
  overflow: hidden;
}

.action-btn::before {
  content: "";
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.2), transparent);
  transition: left 0.5s;
}

.action-btn:hover::before {
  left: 100%;
}

.action-btn:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
  border-color: var(--primary-color);
}

.action-btn.danger {
  border-color: var(--danger-color);
  color: var(--danger-color);
}

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

.action-icon {
  font-size: 18px;
}

.action-label {
  font-size: 11px;
  opacity: 0.9;
}

/* File Actions */
.file-actions {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.file-input {
  display: none;
}

.file-btn {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
  padding: 16px;
  border-radius: var(--radius);
  cursor: pointer;
  font-weight: 500;
  transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  text-decoration: none;
  border: 2px solid transparent;
  min-height: 70px;
  justify-content: center;
  position: relative;
  overflow: hidden;
}

.file-btn::before {
  content: "";
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.2), transparent);
  transition: left 0.5s;
}

.file-btn:hover::before {
  left: 100%;
}

.import-btn {
  background: linear-gradient(135deg, var(--success-color), #059669);
  color: white;
}

.export-btn {
  background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
  color: white;
}

.file-btn:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

.file-icon {
  font-size: 20px;
}

.file-label {
  font-size: 12px;
  opacity: 0.95;
}

/* Mobile Toolbar */
.mobile-toolbar {
  display: none;
  background: var(--background);
  border-bottom: 1px solid var(--border);
  padding: 12px;
  gap: 8px;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: center;
  backdrop-filter: blur(20px);
}

.mobile-toolbar-section {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
}

.mobile-tool-btn {
  background: var(--surface);
  border: 2px solid var(--border);
  border-radius: var(--radius);
  padding: 10px;
  cursor: pointer;
  transition: all 0.2s ease;
  font-size: 16px;
  min-width: 44px;
  min-height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.mobile-tool-btn:hover {
  border-color: var(--primary-color);
  background: var(--surface-hover);
}

.mobile-tool-btn.active {
  background: var(--primary-color);
  border-color: var(--primary-color);
  color: white;
}

.mobile-color-group {
  display: flex;
  gap: 4px;
}

.mobile-color-input {
  width: 44px;
  height: 44px;
  border: 2px solid var(--border);
  border-radius: var(--radius);
  cursor: pointer;
  background: none;
}

.mobile-slider {
  width: 80px;
  height: 4px;
  border-radius: 2px;
  background: var(--border-light);
  outline: none;
  cursor: pointer;
  -webkit-appearance: none;
  appearance: none;
}

.mobile-slider::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--primary-color);
  cursor: pointer;
  border: 2px solid white;
  box-shadow: var(--shadow);
}

.mobile-action-btn {
  background: var(--surface);
  border: 2px solid var(--border);
  border-radius: var(--radius);
  padding: 10px;
  cursor: pointer;
  transition: all 0.2s ease;
  font-size: 14px;
  min-width: 44px;
  min-height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-primary);
}

.mobile-action-btn:hover {
  border-color: var(--primary-color);
  background: var(--surface-hover);
}

.mobile-action-btn.danger {
  border-color: var(--danger-color);
  color: var(--danger-color);
}

.mobile-action-btn.success {
  border-color: var(--success-color);
  color: var(--success-color);
}

/* Canvas Container */
.canvas-container {
  flex: 1;
  display: flex;
  flex-direction: column;
  background: var(--surface);
  position: relative;
  overflow: hidden;
}

.canvas-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 16px 20px;
  background: var(--background);
  border-bottom: 1px solid var(--border);
}

.canvas-info {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.canvas-title {
  font-size: 16px;
  font-weight: 600;
  color: var(--text-primary);
}

.canvas-status {
  font-size: 12px;
  color: var(--text-secondary);
}

.canvas-controls {
  display: flex;
  gap: 8px;
}

.control-btn {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 8px;
  cursor: pointer;
  transition: all 0.2s ease;
  color: var(--text-secondary);
}

.control-btn:hover {
  background: var(--surface-hover);
  border-color: var(--primary-color);
  color: var(--primary-color);
}

.canvas-wrapper {
  flex: 1;
  position: relative;
  overflow: hidden;
  background: white;
}

#canvas {
  display: block;
  cursor: crosshair;
  background: white;
  touch-action: none;
  width: 100%;
  height: 100%;
}

.grid-canvas {
  position: absolute;
  top: 0;
  left: 0;
  pointer-events: none;
  opacity: 0.1;
  transition: opacity 0.3s ease;
}

.grid-canvas.visible {
  opacity: 0.3;
}

/* Zoom Controls */
.zoom-controls {
  position: absolute;
  bottom: 20px;
  right: 20px;
  display: flex;
  align-items: center;
  gap: 4px;
  background: rgba(255, 255, 255, 0.95);
  padding: 8px 12px;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
  backdrop-filter: blur(20px);
  border: 1px solid var(--border-light);
}

.zoom-btn {
  background: var(--surface);
  color: var(--text-primary);
  border: 1px solid var(--border);
  width: 32px;
  height: 32px;
  border-radius: var(--radius);
  cursor: pointer;
  font-size: 16px;
  font-weight: 600;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.2s ease;
}

.zoom-btn:hover {
  background: var(--primary-color);
  color: white;
  border-color: var(--primary-color);
  transform: scale(1.05);
}

.zoom-btn.reset {
  background: var(--success-color);
  color: white;
  border-color: var(--success-color);
}

.zoom-level {
  font-size: 12px;
  font-weight: 500;
  color: var(--text-secondary);
  min-width: 40px;
  text-align: center;
  padding: 0 8px;
}

/* Loading Overlay */
.loading-overlay {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(255, 255, 255, 0.9);
  display: none;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 16px;
  backdrop-filter: blur(10px);
  z-index: 1000;
}

.loading-overlay.visible {
  display: flex;
}

.loading-spinner {
  width: 40px;
  height: 40px;
  border: 4px solid var(--border-light);
  border-top: 4px solid var(--primary-color);
  border-radius: 50%;
  animation: spin 1s linear infinite;
}

@keyframes spin {
  0% {
    transform: rotate(0deg);
  }
  100% {
    transform: rotate(360deg);
  }
}

.loading-text {
  font-size: 14px;
  color: var(--text-secondary);
  font-weight: 500;
}

/* Modal Styles */
.modal-overlay {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(0, 0, 0, 0.5);
  display: none;
  align-items: center;
  justify-content: center;
  z-index: 2000;
  backdrop-filter: blur(10px);
}

.modal-overlay.visible {
  display: flex;
}

.modal-content {
  background: var(--surface);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-xl);
  max-width: 500px;
  width: 90%;
  max-height: 80vh;
  overflow: hidden;
}

.modal-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 20px;
  border-bottom: 1px solid var(--border);
}

.modal-header h3 {
  font-size: 18px;
  font-weight: 600;
  color: var(--text-primary);
}

.modal-close {
  background: none;
  border: none;
  font-size: 24px;
  cursor: pointer;
  color: var(--text-secondary);
  padding: 4px;
  border-radius: var(--radius);
  transition: all 0.2s ease;
}

.modal-close:hover {
  background: var(--surface-hover);
  color: var(--text-primary);
}

.modal-body {
  padding: 20px;
}

/* Responsive Design */
@media (max-width: 1024px) {
  .sidebar {
    width: 280px;
  }

  .tool-group {
    margin: 12px;
    padding: 16px;
  }
}

@media (max-width: 768px) {
  .app-container {
    flex-direction: column;
    margin: 4px;
    border-radius: var(--radius-lg);
  }

  .sidebar {
    display: none;
  }

  .mobile-toolbar {
    display: flex;
    padding: 8px;
    min-height: 70px;
  }

  .canvas-header {
    padding: 12px 16px;
  }

  .canvas-title {
    font-size: 14px;
  }

  .zoom-controls {
    bottom: 10px;
    right: 10px;
    padding: 6px 8px;
  }

  .zoom-btn {
    width: 28px;
    height: 28px;
    font-size: 14px;
  }

  .zoom-level {
    font-size: 11px;
    min-width: 35px;
    padding: 0 6px;
  }
}

@media (max-width: 480px) {
  .mobile-toolbar {
    padding: 6px;
    gap: 6px;
  }

  .mobile-toolbar-section {
    gap: 6px;
  }

  .mobile-tool-btn,
  .mobile-color-input,
  .mobile-action-btn {
    min-width: 40px;
    min-height: 40px;
    font-size: 14px;
  }

  .mobile-slider {
    width: 60px;
  }

  .canvas-header {
    padding: 8px 12px;
  }

  .zoom-controls {
    bottom: 8px;
    right: 8px;
    padding: 4px 6px;
    gap: 2px;
  }

  .zoom-btn {
    width: 24px;
    height: 24px;
    font-size: 12px;
  }

  .zoom-level {
    font-size: 10px;
    min-width: 30px;
    padding: 0 4px;
  }
}

/* Accessibility */
.tool-btn:focus,
.action-btn:focus,
.file-btn:focus,
.zoom-btn:focus,
.slider:focus,
.color-input:focus,
.mobile-tool-btn:focus,
.mobile-action-btn:focus {
  outline: 2px solid var(--primary-color);
  outline-offset: 2px;
}

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

@keyframes slideIn {
  from {
    transform: translateX(-100%);
  }
  to {
    transform: translateX(0);
  }
}

.tool-group {
  animation: fadeIn 0.3s ease-out;
}

.sidebar {
  animation: slideIn 0.3s ease-out;
}

/* Custom Scrollbar */
.sidebar::-webkit-scrollbar {
  width: 6px;
}

.sidebar::-webkit-scrollbar-track {
  background: var(--border-light);
  border-radius: 3px;
}

.sidebar::-webkit-scrollbar-thumb {
  background: var(--border);
  border-radius: 3px;
  transition: background 0.2s ease;
}

.sidebar::-webkit-scrollbar-thumb:hover {
  background: var(--text-muted);
}

/* Prevent text selection on UI elements */
.tool-btn,
.action-btn,
.file-btn,
.zoom-btn,
.mobile-tool-btn,
.mobile-action-btn,
.tool-group h3,
.app-title {
  user-select: none;
  -webkit-user-select: none;
  -moz-user-select: none;
  -ms-user-select: none;
}

/* High contrast mode support */
@media (prefers-contrast: high) {
  :root {
    --border: #000000;
    --border-light: #333333;
    --shadow: 0 2px 4px rgba(0, 0, 0, 0.3);
  }
}

/* Reduced motion support */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}