:root {
  --bg-primary: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  --bg-secondary: rgba(255, 255, 255, 0.95);
  --bg-glass: rgba(255, 255, 255, 0.25);
  --bg-glass-hover: rgba(255, 255, 255, 0.35);
  --text-primary: #1a1a1a;
  --text-secondary: #666;
  --border-color: rgba(255, 255, 255, 0.3);
  --shadow-sm: 0 2px 10px rgba(0, 0, 0, 0.1);
  --shadow-md: 0 4px 20px rgba(0, 0, 0, 0.15);
  --shadow-lg: 0 8px 30px rgba(0, 0, 0, 0.2);
  --canvas-bg: #ffffff;
  --grid-color: rgba(0, 0, 0, 0.05);
}

[data-theme="dark"] {
  --bg-primary: linear-gradient(135deg, #1a1a2e 0%, #16213e 100%);
  --bg-secondary: rgba(30, 30, 46, 0.95);
  --bg-glass: rgba(255, 255, 255, 0.1);
  --bg-glass-hover: rgba(255, 255, 255, 0.15);
  --text-primary: #e0e0e0;
  --text-secondary: #b0b0b0;
  --border-color: rgba(255, 255, 255, 0.2);
  --shadow-sm: 0 2px 10px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 20px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 8px 30px rgba(0, 0, 0, 0.5);
  --canvas-bg: #1e1e2e;
  --grid-color: rgba(255, 255, 255, 0.1);
}
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  background: var(--bg-primary);
  color: var(--text-primary);
  min-height: 100vh;
  overflow: hidden;
  transition: background 0.3s ease;
}

.hidden {
  display: none !important;
}

/* Welcome Screen */
.welcome-screen {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: var(--bg-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1000;
  animation: fadeIn 0.9s ease;
}

.welcome-content {
  background: var(--bg-glass);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border: 1px solid var(--border-color);
  border-radius: 30px;
  padding: 60px 40px;
  text-align: center;
  box-shadow: var(--shadow-lg);
  max-width: 500px;
  width: 90%;
  animation: slideUp 0.6s ease;
}

.welcome-icon {
  font-size: 80px;
  margin-bottom: 20px;
  animation: bounce 2s infinite;
}

.welcome-content h1 {
  font-size: 2.5rem;
  margin-bottom: 10px;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.welcome-content p {
  font-size: 1.1rem;
  color: var(--text-secondary);
  margin-bottom: 30px;
}

.welcome-features {
  display: flex;
  flex-direction: column;
  gap: 15px;
  margin-bottom: 30px;
}

.feature-item {
  padding: 12px 20px;
  background: var(--bg-glass-hover);
  border-radius: 15px;
  font-size: 1rem;
  backdrop-filter: blur(10px);
  border: 1px solid var(--border-color);
  animation: fadeIn 0.8s ease backwards;
}

.feature-item:nth-child(1) { animation-delay: 0.1s; }
.feature-item:nth-child(2) { animation-delay: 0.2s; }
.feature-item:nth-child(3) { animation-delay: 0.3s; }
.feature-item:nth-child(4) { animation-delay: 0.4s; }

.start-btn {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: white;
  border: none;
  padding: 15px 40px;
  font-size: 1.1rem;
  border-radius: 25px;
  cursor: pointer;
  transition: all 0.3s ease;
  box-shadow: var(--shadow-md);
  font-weight: 600;
}

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

.start-btn:active {
  transform: translateY(0);
}

.shortcuts-hint {
  margin-top: 20px;
  font-size: 0.9rem;
  color: var(--text-secondary);
}

/* Main Application */
.app {
  display: flex;
  flex-direction: column;
  height: 100vh;
  animation: fadeIn 0.5s ease;
}

/* Header */
.header {
  background: var(--bg-glass);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border-color);
  padding: 15px 25px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  box-shadow: var(--shadow-sm);
  z-index: 100;
}

.header-left {
  display: flex;
  align-items: center;
  gap: 20px;
}

.logo {
  font-size: 1.8rem;
  font-weight: 700;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.theme-toggle-container {
  position: relative;
}

.theme-toggle {
  background: var(--bg-glass-hover);
  border: 1px solid var(--border-color);
  border-radius: 50%;
  width: 45px;
  height: 45px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all 0.3s ease;
  backdrop-filter: blur(10px);
  font-size: 1.3rem;
}

.theme-toggle:hover {
  transform: rotate(15deg) scale(1.1);
  background: var(--bg-glass);
}

.header-right {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
}

.header-btn {
  background: var(--bg-glass-hover);
  border: 1px solid var(--border-color);
  color: var(--text-primary);
  padding: 10px 20px;
  border-radius: 15px;
  cursor: pointer;
  transition: all 0.3s ease;
  backdrop-filter: blur(10px);
  font-size: 0.95rem;
  font-weight: 500;
  display: flex;
  align-items: center;
  gap: 8px;
}

.header-btn:hover {
  transform: translateY(-2px);
  background: var(--bg-glass);
  box-shadow: var(--shadow-md);
}

.header-btn.active {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: white;
  border-color: transparent;
}

.download-btn {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: white;
  border: none;
}

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

/* Toolbar */
.toolbar {
  background: var(--bg-glass);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border-color);
  padding: 15px 25px;
  display: flex;
  flex-wrap: wrap;
  gap: 20px;
  align-items: center;
  justify-content: space-between;
  box-shadow: var(--shadow-sm);
  z-index: 99;
  overflow-x: auto;
}

.toolbar-section {
  display: flex;
  gap: 15px;
  align-items: center;
  flex-wrap: wrap;
}

.tool-group {
  display: flex;
  gap: 8px;
  background: var(--bg-glass-hover);
  padding: 8px;
  border-radius: 15px;
  border: 1px solid var(--border-color);
  backdrop-filter: blur(10px);
}

.tool-btn {
  background: transparent;
  border: none;
  padding: 12px 18px;
  border-radius: 12px;
  cursor: pointer;
  transition: all 0.3s ease;
  color: var(--text-primary);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 5px;
  font-size: 1.2rem;
  min-width: 70px;
  position: relative;
}

.tool-btn:hover {
  background: var(--bg-glass);
  transform: translateY(-2px);
}

.tool-btn.active {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: white;
  box-shadow: var(--shadow-md);
}

.tool-label {
  font-size: 0.75rem;
  font-weight: 500;
}

.action-btn {
  min-width: 80px;
}

.clear-btn {
  background: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
  color: white;
}

.clear-btn:hover {
  background: linear-gradient(135deg, #f5576c 0%, #f093fb 100%);
}

/* Control Groups */
.control-group {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.control-label {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.color-picker-container {
  display: flex;
  gap: 10px;
  align-items: center;
}

#colorPicker {
  width: 50px;
  height: 50px;
  border: 2px solid var(--border-color);
  border-radius: 12px;
  cursor: pointer;
  background: transparent;
  padding: 0;
}

#colorInput {
  background: var(--bg-glass-hover);
  border: 1px solid var(--border-color);
  border-radius: 10px;
  padding: 10px 15px;
  color: var(--text-primary);
  font-size: 0.9rem;
  width: 120px;
  backdrop-filter: blur(10px);
}

#colorInput:focus {
  outline: none;
  border-color: #667eea;
  box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.2);
}

.brush-size-container {
  display: flex;
  align-items: center;
  gap: 15px;
  background: var(--bg-glass-hover);
  padding: 10px 15px;
  border-radius: 12px;
  border: 1px solid var(--border-color);
  backdrop-filter: blur(10px);
}

#brushSize {
  flex: 1;
  height: 6px;
  border-radius: 3px;
  background: var(--bg-glass);
  outline: none;
  cursor: pointer;
}

#brushSize::-webkit-slider-thumb {
  appearance: none;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  cursor: pointer;
  box-shadow: var(--shadow-sm);
}

#brushSize::-moz-range-thumb {
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  cursor: pointer;
  border: none;
  box-shadow: var(--shadow-sm);
}

#brushSizeValue {
  font-size: 0.9rem;
  font-weight: 600;
  min-width: 45px;
  text-align: right;
}

/* Canvas Container */
.canvas-container {
  flex: 1;
  position: relative;
  overflow: hidden;
  background: var(--canvas-bg);
  display: flex;
  align-items: center;
  justify-content: center;
}

.canvas-container > * {
  position: relative;
}

#canvas {
  cursor: crosshair;
  touch-action: none;
  background: var(--canvas-bg);
  display: block;
}

.grid-overlay {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  background-image: 
    linear-gradient(var(--grid-color) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid-color) 1px, transparent 1px);
  background-size: 20px 20px;
  opacity: 0.5;
}

/* Text Input Container */
.text-input-container {
  position: absolute;
  background: var(--bg-glass);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border: 1px solid var(--border-color);
  border-radius: 20px;
  padding: 25px;
  box-shadow: var(--shadow-lg);
  z-index: 200;
  min-width: 300px;
  animation: slideUp 0.3s ease;
  transform: translate(-50%, -50%);
}

#textInput {
  width: 100%;
  padding: 15px;
  border: 2px solid var(--border-color);
  border-radius: 12px;
  background: var(--bg-glass-hover);
  color: var(--text-primary);
  font-size: 1.1rem;
  margin-bottom: 15px;
  backdrop-filter: blur(10px);
}

#textInput:focus {
  outline: none;
  border-color: #667eea;
  box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.2);
}

.text-input-actions {
  display: flex;
  gap: 10px;
  justify-content: flex-end;
}

.text-btn {
  padding: 10px 20px;
  border: none;
  border-radius: 10px;
  cursor: pointer;
  font-size: 0.95rem;
  font-weight: 600;
  transition: all 0.3s ease;
}

#textConfirmBtn {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: white;
}

#textConfirmBtn:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

#textCancelBtn {
  background: var(--bg-glass-hover);
  color: var(--text-primary);
  border: 1px solid var(--border-color);
}

#textCancelBtn:hover {
  background: var(--bg-glass);
}
.footer {
  background: var(--bg-glass);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-top: 1px solid var(--border-color);
  padding: 15px 25px;
  text-align: center;
  font-size: 0.9rem;
  color: var(--text-secondary);
  box-shadow: var(--shadow-sm);
  z-index: 98;
}

.footer-shortcuts {
  margin-top: 5px;
  font-size: 0.85rem;
}

kbd {
  background: var(--bg-glass-hover);
  border: 1px solid var(--border-color);
  border-radius: 4px;
  padding: 3px 8px;
  font-family: monospace;
  font-size: 0.85rem;
  box-shadow: var(--shadow-sm);
}

/* Modal */
.modal {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.5);
  backdrop-filter: blur(5px);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1000;
  animation: fadeIn 0.3s ease;
}

.modal-content {
  background: var(--bg-glass);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border: 1px solid var(--border-color);
  border-radius: 25px;
  padding: 30px;
  max-width: 500px;
  width: 90%;
  max-height: 80vh;
  overflow-y: auto;
  box-shadow: var(--shadow-lg);
  animation: slideUp 0.4s ease;
}

.modal-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 25px;
}

.modal-header h2 {
  font-size: 1.8rem;
}

.close-btn {
  background: transparent;
  border: none;
  font-size: 2rem;
  cursor: pointer;
  color: var(--text-primary);
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  transition: all 0.3s ease;
}

.close-btn:hover {
  background: var(--bg-glass-hover);
  transform: rotate(90deg);
}

.modal-body {
  display: flex;
  flex-direction: column;
  gap: 15px;
}

.shortcut-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 12px 15px;
  background: var(--bg-glass-hover);
  border-radius: 12px;
  border: 1px solid var(--border-color);
}

.shortcut-item kbd {
  display: inline-flex;
  gap: 5px;
}

/* Animations */
@keyframes fadeIn {
  from {
    opacity: 0;
  }
  to {
    opacity: 1;
  }
}

@keyframes slideUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

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

/* Responsive Design */
@media (max-width: 768px) {
  .header {
    flex-direction: column;
    gap: 15px;
    padding: 15px;
  }

  .header-left,
  .header-right {
    width: 100%;
    justify-content: center;
  }

  .toolbar {
    flex-direction: column;
    align-items: stretch;
    padding: 15px;
  }

  .toolbar-section {
    justify-content: center;
  }

  .tool-group {
    flex-wrap: wrap;
    justify-content: center;
  }

  .tool-btn {
    min-width: 60px;
    padding: 10px 12px;
    font-size: 1rem;
  }

  .tool-label {
    font-size: 0.7rem;
  }

  .welcome-content {
    padding: 40px 25px;
  }

  .welcome-content h1 {
    font-size: 2rem;
  }

  .logo {
    font-size: 1.5rem;
  }

  .color-picker-container {
    flex-direction: column;
  }

  #colorInput {
    width: 100%;
  }
}

@media (max-width: 480px) {
  .tool-btn {
    min-width: 50px;
    padding: 8px 10px;
  }

  .header-btn {
    padding: 8px 15px;
    font-size: 0.85rem;
  }

  .welcome-content {
    padding: 30px 20px;
  }

  .welcome-icon {
    font-size: 60px;
  }
}

/* Tooltip Styles */
.tool-btn[title]:hover::after,
.header-btn[title]:hover::after {
  content: attr(title);
  position: absolute;
  bottom: 100%;
  left: 50%;
  transform: translateX(-50%);
  background: rgba(0, 0, 0, 0.9);
  color: white;
  padding: 6px 12px;
  border-radius: 6px;
  font-size: 0.8rem;
  white-space: nowrap;
  margin-bottom: 5px;
  z-index: 1000;
  pointer-events: none;
  animation: fadeIn 0.2s ease;
}

.tool-btn[title]:hover::before {
  content: '';
  position: absolute;
  bottom: 100%;
  left: 50%;
  transform: translateX(-50%);
  border: 5px solid transparent;
  border-top-color: rgba(0, 0, 0, 0.9);
  margin-bottom: -5px;
  z-index: 1000;
  pointer-events: none;
}