:root {
  --bg-primary: #0d1117;
  --bg-secondary: #161b22;
  --bg-tertiary: #21262d;
  --border-color: #30363d;
  --border-hover: #484f58;
  --text-primary: #e6edf3;
  --text-secondary: #7d8590;
  --text-muted: #656d76;
  --accent-primary: #58a6ff;
  --accent-hover: #4493f8;
  --success-color: #238636;
  --danger-color: #da3633;
  --warning-color: #f0883e;
  --shadow: 0 8px 32px rgba(0, 0, 0, 0.32);
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.24);
  --radius: 8px;
  --radius-sm: 6px;
  --transition: all 0.2s ease;
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.5;
  overflow: hidden;
}

.app-container {
  display: grid;
  grid-template-columns: 400px 1fr;
  height: 100vh;
}

.chat-panel {
  background: var(--bg-secondary);
  border-right: 1px solid var(--border-color);
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

.chat-header {
  padding: 24px 24px 16px;
  border-bottom: 1px solid var(--border-color);
  background: var(--bg-secondary);
}

.chat-header h1 {
  font-size: 20px;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 4px;
}

.chat-header p {
  color: var(--text-secondary);
  font-size: 14px;
}

.chat-messages {
  flex: 1;
  overflow-y: auto;
  padding: 16px;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.chat-messages::-webkit-scrollbar {
  width: 6px;
}

.chat-messages::-webkit-scrollbar-track {
  background: transparent;
}

.chat-messages::-webkit-scrollbar-thumb {
  background: var(--border-color);
  border-radius: 3px;
}

.chat-messages::-webkit-scrollbar-thumb:hover {
  background: var(--border-hover);
}

.message {
  display: flex;
  gap: 12px;
  animation: slideIn 0.3s ease-out;
}

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

.message.user {
  flex-direction: row-reverse;
}

.message-avatar {
  width: 32px;
  height: 32px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 12px;
  font-weight: 600;
  flex-shrink: 0;
}

.message.system .message-avatar {
  background: linear-gradient(135deg, var(--accent-primary), #8b5cf6);
  color: white;
}

.message.user .message-avatar {
  background: var(--bg-tertiary);
  color: var(--text-secondary);
}

.message-content {
  flex: 1;
  background: var(--bg-tertiary);
  padding: 12px 16px;
  border-radius: var(--radius);
  border: 1px solid var(--border-color);
}

.message.user .message-content {
  background: var(--accent-primary);
  color: white;
  border-color: var(--accent-primary);
}

.message-content p {
  margin: 0;
  font-size: 14px;
  line-height: 1.4;
}

.suggestions {
  margin-top: 16px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.suggestion-btn {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  color: var(--text-secondary);
  padding: 8px 12px;
  border-radius: var(--radius-sm);
  font-size: 13px;
  cursor: pointer;
  transition: var(--transition);
  text-align: left;
}

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

.chat-input-area {
  padding: 16px;
  border-top: 1px solid var(--border-color);
  background: var(--bg-secondary);
}

.input-container {
  position: relative;
  background: var(--bg-tertiary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  transition: var(--transition);
}

.input-container:focus-within {
  border-color: var(--accent-primary);
  box-shadow: 0 0 0 3px rgba(88, 166, 255, 0.1);
}

.chat-form textarea {
  width: 100%;
  background: transparent;
  border: none;
  padding: 12px 48px 12px 16px;
  color: var(--text-primary);
  font-size: 14px;
  resize: none;
  font-family: inherit;
  outline: none;
}

.chat-form textarea::placeholder {
  color: var(--text-muted);
}

.send-btn {
  position: absolute;
  right: 8px;
  bottom: 8px;
  background: var(--accent-primary);
  border: none;
  color: white;
  width: 32px;
  height: 32px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: var(--transition);
}

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

.send-btn:disabled {
  background: var(--bg-tertiary);
  color: var(--text-muted);
  cursor: not-allowed;
}

.preview-panel {
  display: flex;
  flex-direction: column;
  background: var(--bg-primary);
}

.preview-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px 24px;
  border-bottom: 1px solid var(--border-color);
  background: var(--bg-secondary);
}

.preview-title {
  display: flex;
  align-items: center;
  gap: 12px;
}

.preview-title h2 {
  font-size: 16px;
  font-weight: 600;
  color: var(--text-primary);
}

.preview-status {
  padding: 4px 8px;
  background: var(--success-color);
  color: white;
  font-size: 12px;
  border-radius: 12px;
  font-weight: 500;
}

.preview-status.generating {
  background: var(--warning-color);
}

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

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

.control-btn {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 6px 12px;
  background: var(--bg-tertiary);
  border: 1px solid var(--border-color);
  color: var(--text-secondary);
  border-radius: var(--radius-sm);
  font-size: 13px;
  cursor: pointer;
  transition: var(--transition);
}

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

.control-btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

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

.preview-content {
  flex: 1;
  position: relative;
  overflow: hidden;
}

.preview-iframe-container {
  width: 100%;
  height: 100%;
  position: relative;
}

#previewFrame {
  width: 100%;
  height: 100%;
  border: none;
  background: white;
}

.preview-placeholder {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--bg-primary);
}

.placeholder-content {
  text-align: center;
  color: var(--text-muted);
}

.placeholder-content svg {
  margin-bottom: 16px;
  opacity: 0.5;
}

.placeholder-content h3 {
  font-size: 16px;
  margin-bottom: 8px;
  color: var(--text-secondary);
}

.placeholder-content p {
  font-size: 14px;
}


.loading-overlay {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(13, 17, 23, 0.8);
  backdrop-filter: blur(4px);
  display: none;
  align-items: center;
  justify-content: center;
  z-index: 1000;
}

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

.loading-spinner {
  text-align: center;
  color: var(--text-primary);
}

.spinner {
  width: 32px;
  height: 32px;
  border: 3px solid var(--border-color);
  border-top: 3px solid var(--accent-primary);
  border-radius: 50%;
  animation: spin 1s linear infinite;
  margin: 0 auto 16px;
}

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

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

/* Typing indicator */
.typing-indicator {
  opacity: 0.8;
}

.typing-dots {
  display: flex;
  gap: 4px;
  align-items: center;
  padding: 8px 0;
}

.typing-dots span {
  width: 8px;
  height: 8px;
  background: var(--text-secondary);
  border-radius: 50%;
  animation: typing 1.4s infinite ease-in-out;
}

.typing-dots span:nth-child(1) { animation-delay: -0.32s; }
.typing-dots span:nth-child(2) { animation-delay: -0.16s; }
.typing-dots span:nth-child(3) { animation-delay: 0s; }

@keyframes typing {
  0%, 80%, 100% {
    opacity: 0.3;
    transform: scale(0.8);
  }
  40% {
    opacity: 1;
    transform: scale(1);
  }
}

/* Enhanced message animations */
.message {
  transition: all 0.3s ease;
}

.message:hover {
  transform: translateX(2px);
}

/* Enhanced suggestion buttons */
.suggestion-btn {
  position: relative;
  overflow: hidden;
}

.suggestion-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 ease;
}

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

/* Status indicator enhancements */
.preview-status {
  position: relative;
}

.preview-status::before {
  content: '';
  position: absolute;
  left: -12px;
  top: 50%;
  transform: translateY(-50%);
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: currentColor;
}

.preview-status.generating::before {
  animation: pulse 1.5s infinite;
}

@keyframes pulse {
  0%, 100% { opacity: 0.5; transform: translateY(-50%) scale(0.8); }
  50% { opacity: 1; transform: translateY(-50%) scale(1.2); }
}

/* Desktop Layout (1200px and above) - Default grid layout */
@media (min-width: 1200px) {
  .app-container {
    grid-template-columns: 420px 1fr;
  }
  
  .chat-header h1 {
    font-size: 22px;
  }
  
  .suggestions {
    flex-direction: row;
    flex-wrap: wrap;
  }
  
  .suggestion-btn {
    flex: 1;
    min-width: 180px;
  }
  
  .preview-controls {
    gap: 12px;
  }
  
  .control-btn {
    padding: 8px 16px;
    font-size: 14px;
  }
}

/* Large Desktop Layout (1440px and above) */
@media (min-width: 1440px) {
  .app-container {
    grid-template-columns: 480px 1fr;
  }
  
  .chat-header {
    padding: 32px 32px 20px;
  }
  
  .chat-messages {
    padding: 24px;
    gap: 20px;
  }
  
  .chat-input-area {
    padding: 24px;
  }
  
  .preview-header {
    padding: 20px 32px;
  }
}

/* Tablet Layout (768px to 1199px) - Adjusted sidebar width */
@media (min-width: 768px) and (max-width: 1199px) {
  .app-container {
    grid-template-columns: 360px 1fr;
  }
  
  .chat-header {
    padding: 20px 20px 14px;
  }
  
  .chat-header h1 {
    font-size: 18px;
  }
  
  .chat-messages {
    padding: 14px;
  }
  
  .message-content {
    padding: 10px 14px;
  }
  
  .suggestions {
    margin-top: 12px;
    gap: 6px;
  }
  
  .suggestion-btn {
    padding: 6px 10px;
    font-size: 12px;
  }
  
  .chat-input-area {
    padding: 14px;
  }
  
  .chat-form textarea {
    padding: 10px 42px 10px 14px;
    font-size: 13px;
  }
  
  .preview-header {
    padding: 14px 20px;
  }
  
  .preview-title h2 {
    font-size: 15px;
  }
  
  .control-btn {
    padding: 5px 10px;
    font-size: 12px;
    gap: 4px;
  }
  
  .control-btn svg {
    width: 14px;
    height: 14px;
  }
}

/* Small Tablet Layout (600px to 767px) - Collapsible sidebar */
@media (min-width: 600px) and (max-width: 767px) {
  .app-container {
    position: relative;
    grid-template-columns: 1fr;
  }
  
  .chat-panel {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    z-index: 200;
    transform: translateX(-100%);
    transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    box-shadow: var(--shadow);
  }
  
  .chat-panel.active {
    transform: translateX(0);
  }
  
  .preview-panel {
    width: 100%;
  }
  
  .preview-header {
    padding-left: 60px;
    position: relative;
  }
  
  .preview-header::before {
    content: '☰';
    position: absolute;
    left: 20px;
    top: 50%;
    transform: translateY(-50%);
    width: 24px;
    height: 24px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    color: var(--text-secondary);
    cursor: pointer;
    font-size: 16px;
    transition: var(--transition);
  }
  
  .preview-header::before:hover {
    background: var(--bg-primary);
    color: var(--text-primary);
    border-color: var(--border-hover);
  }
  
  .suggestions {
    flex-direction: column;
    gap: 8px;
  }
  
  .suggestion-btn {
    width: 100%;
  }
}

/* Safe Area Support for Mobile */
@supports (padding: max(0px)) {
  body {
    padding-left: env(safe-area-inset-left);
    padding-right: env(safe-area-inset-right);
  }
}

/* Hide mobile-specific elements on desktop */
.mobile-reset-btn {
  display: none;
}

/* Mobile Layout (320px to 599px) - Bottom modal chat interface */
@media (max-width: 599px) {
  .app-container {
    grid-template-columns: 1fr;
    grid-template-rows: 1fr;
    height: 100vh;
    overflow: hidden;
    position: relative;
  }
  
  /* Full-screen preview on mobile */
  .preview-panel {
    width: 100%;
    height: 100vh;
    grid-column: 1;
    grid-row: 1;
  }
  
  .preview-header {
    padding: 12px 16px;
    position: relative;
  }
  
  .preview-title h2 {
    font-size: 16px;
  }
  
  .preview-status {
    font-size: 11px;
    padding: 3px 6px;
  }
  
  .preview-controls {
    gap: 6px;
  }
  
  .control-btn {
    padding: 6px 8px;
    font-size: 11px;
    gap: 3px;
    min-width: auto;
  }
  
  .control-btn svg {
    width: 12px;
    height: 12px;
  }
  
  /* Bottom modal chat panel */
  .chat-panel {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    height: 60vh;
    max-height: 500px;
    background: var(--bg-secondary);
    border-top: 1px solid var(--border-color);
    border-radius: 16px 16px 0 0;
    box-shadow: 0 -8px 32px rgba(0, 0, 0, 0.4);
    transform: translateY(calc(100% - 80px));
    transition: transform 0.4s cubic-bezier(0.25, 0.46, 0.45, 0.94);
    z-index: 1000;
    display: flex;
    flex-direction: column;
  }
  
  .chat-panel.active {
    transform: translateY(0);
  }
  
  .chat-panel.collapsed {
    transform: translateY(calc(100% - 80px));
  }
  
  /* Chat panel drag handle */
  .chat-panel::before {
    content: '';
    position: absolute;
    top: 8px;
    left: 50%;
    transform: translateX(-50%);
    width: 40px;
    height: 4px;
    background: var(--text-muted);
    border-radius: 2px;
    opacity: 0.6;
  }
  
  .chat-header {
    padding: max(20px, env(safe-area-inset-top) + 20px) 16px 12px;
    text-align: center;
    cursor: pointer;
    user-select: none;
    border-bottom: 1px solid var(--border-color);
    flex-shrink: 0;
  }
  
  .chat-header-content {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
  }
  
  .chat-title {
    flex: 1;
    text-align: center;
  }
  
  .mobile-reset-btn {
    display: flex !important;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    color: var(--text-secondary);
    cursor: pointer;
    transition: var(--transition);
    flex-shrink: 0;
  }
  
  .mobile-reset-btn:hover,
  .mobile-reset-btn:active {
    background: var(--danger-color);
    color: white;
    border-color: var(--danger-color);
    transform: scale(0.95);
  }
  
  .chat-header h1 {
    font-size: 16px;
    margin-bottom: 2px;
    color: var(--text-primary);
  }
  
  .chat-header p {
    font-size: 12px;
    color: var(--text-secondary);
  }
  
  .chat-messages {
    flex: 1;
    padding: 12px;
    gap: 12px;
    overflow-y: auto;
    max-height: calc(60vh - 160px);
  }
  
  .message {
    gap: 8px;
  }
  
  .message-avatar {
    width: 28px;
    height: 28px;
    font-size: 11px;
  }
  
  .message-content {
    padding: 8px 12px;
    border-radius: var(--radius-sm);
  }
  
  .message-content p {
    font-size: 13px;
    line-height: 1.4;
  }
  
  .suggestions {
    margin-top: 12px;
    gap: 8px;
  }
  
  .suggestion-btn {
    padding: 8px 12px;
    font-size: 12px;
    text-align: center;
    min-height: 44px;
    display: flex;
    align-items: center;
    justify-content: center;
  }
  
  .chat-input-area {
    padding: 12px;
    padding-bottom: max(12px, env(safe-area-inset-bottom) + 12px);
    background: var(--bg-secondary);
    border-top: 1px solid var(--border-color);
    flex-shrink: 0;
  }
  
  .chat-form textarea {
    padding: 12px 48px 12px 12px;
    font-size: 16px; /* Prevents zoom on iOS */
    min-height: 44px;
    border-radius: var(--radius);
  }
  
  .send-btn {
    width: 40px;
    height: 40px;
    right: 8px;
    bottom: 8px;
    border-radius: var(--radius);
  }
  
  /* Floating chat button when collapsed */
  .chat-toggle-btn {
    position: fixed;
    bottom: max(20px, env(safe-area-inset-bottom) + 20px);
    right: max(20px, env(safe-area-inset-right) + 20px);
    width: 56px;
    height: 56px;
    background: var(--accent-primary);
    border: none;
    border-radius: 50%;
    color: white;
    box-shadow: 0 4px 16px rgba(88, 166, 255, 0.3);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 24px;
    transition: all 0.3s ease;
    z-index: 999;
    touch-action: manipulation;
  }
  
  .chat-toggle-btn:hover,
  .chat-toggle-btn:active {
    background: var(--accent-hover);
    transform: scale(1.1);
    box-shadow: 0 6px 20px rgba(88, 166, 255, 0.4);
  }
  
  .chat-toggle-btn.hidden {
    transform: scale(0);
    opacity: 0;
  }
  
  /* Hide button text on very small screens */
  @media (max-width: 400px) {
    .control-btn span {
      display: none;
    }
    
    .control-btn {
      width: 32px;
      height: 32px;
      padding: 0;
      display: flex;
      align-items: center;
      justify-content: center;
    }
    
    .chat-panel {
      height: 65vh;
      transform: translateY(calc(100% - 70px));
    }
    
    .chat-panel.collapsed {
      transform: translateY(calc(100% - 70px));
    }
    
    .chat-header {
      padding: 16px 12px 10px;
    }
    
    .chat-messages {
      max-height: calc(65vh - 140px);
    }
  }
  
  /* Backdrop for modal */
  .chat-backdrop {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.2);
    backdrop-filter: blur(2px);
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
    z-index: 999;
  }
  
  .chat-backdrop.active {
    opacity: 1;
    visibility: visible;
  }
}

/* Large Mobile Layout (480px to 599px) - Improved spacing */
@media (min-width: 480px) and (max-width: 599px) {
  .chat-header {
    padding: 20px 20px 16px;
  }
  
  .chat-header h1 {
    font-size: 20px;
  }
  
  .chat-messages {
    padding: 16px;
    gap: 16px;
  }
  
  .message-avatar {
    width: 32px;
    height: 32px;
    font-size: 12px;
  }
  
  .message-content {
    padding: 10px 14px;
  }
  
  .message-content p {
    font-size: 14px;
  }
  
  .chat-input-area {
    padding: 16px;
  }
  
  .preview-header {
    padding: 16px 20px;
    padding-left: 64px;
  }
}

/* Touch device optimizations */
@media (hover: none) and (pointer: coarse) {
  .suggestion-btn,
  .control-btn,
  .send-btn {
    min-height: 44px;
    touch-action: manipulation;
  }
  
  .chat-form textarea {
    font-size: 16px; /* Prevents zoom on iOS */
  }
  
  /* Larger touch targets */
  .message:hover {
    transform: none;
  }
  
  .suggestion-btn:hover::before {
    display: none;
  }
}