/* CSS Variables */
:root {
  /* Dark theme (default) */
  --bg-primary: #1a1b26;
  --bg-secondary: #24283b;
  --bg-tertiary: #1f2335;
  --fg-primary: #a9b1d6;
  --fg-secondary: #7aa2f7;
  --fg-muted: #565f89;
  --border-color: #3d59a1;
  --accent: #7aa2f7;
  --success: #9ece6a;
  --error: #f7768e;
  --radius: 8px;
  --transition: 0.2s ease;
}

/* Light theme */
[data-theme="light"] {
  --bg-primary: #f5f5f5;
  --bg-secondary: #ffffff;
  --bg-tertiary: #e8e8e8;
  --fg-primary: #1a1b26;
  --fg-secondary: #2e5cb8;
  --fg-muted: #6b7280;
  --border-color: #d1d5db;
  --accent: #2563eb;
  --success: #059669;
  --error: #dc2626;
}

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

/* Base */
html, body {
  height: 100%;
  font-family: 'Inter', system-ui, -apple-system, sans-serif;
  background: var(--bg-primary);
  color: var(--fg-primary);
  line-height: 1.5;
}

/* Layout */
.app {
  display: flex;
  flex-direction: column;
  height: 100vh;
  overflow: hidden;
}

/* Header */
.header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 20px;
  background: var(--bg-secondary);
  border-bottom: 1px solid var(--border-color);
  flex-shrink: 0;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 18px;
  font-weight: 600;
  color: var(--fg-secondary);
}

.logo-icon {
  font-size: 24px;
}

/* Site Theme Toggle */
.theme-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  background: var(--bg-tertiary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  cursor: pointer;
  transition: all var(--transition);
  font-size: 18px;
}

.theme-toggle:hover {
  border-color: var(--accent);
  background: var(--bg-secondary);
}

.theme-toggle:focus {
  outline: none;
  border-color: var(--accent);
}

/* Show/hide icons based on theme */
.theme-icon-light {
  display: none;
}

.theme-icon-dark {
  display: block;
}

[data-theme="light"] .theme-icon-light {
  display: block;
}

[data-theme="light"] .theme-icon-dark {
  display: none;
}

/* Diagram Theme Select */
.diagram-theme-select {
  padding: 6px 10px;
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  color: var(--fg-primary);
  font-size: 13px;
  cursor: pointer;
  transition: border-color var(--transition);
}

.diagram-theme-select:hover {
  border-color: var(--accent);
}

.diagram-theme-select:focus {
  outline: none;
  border-color: var(--accent);
}

/* Navigation */
.nav {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 12px 20px;
  background: var(--bg-tertiary);
  border-bottom: 1px solid var(--border-color);
  flex-shrink: 0;
}

.category-tabs {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

.category-tab {
  padding: 8px 16px;
  background: transparent;
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  color: var(--fg-muted);
  font-size: 14px;
  font-weight: 500;
  cursor: pointer;
  transition: all var(--transition);
}

.category-tab:hover {
  border-color: var(--accent);
  color: var(--fg-primary);
}

.category-tab.active {
  background: var(--accent);
  border-color: var(--accent);
  color: var(--bg-primary);
}

.example-pills {
  display: flex;
  gap: 6px;
  flex-wrap: wrap;
}

.example-pill {
  padding: 4px 12px;
  background: var(--bg-secondary);
  border: 1px solid transparent;
  border-radius: 20px;
  color: var(--fg-muted);
  font-size: 13px;
  cursor: pointer;
  transition: all var(--transition);
}

.example-pill:hover {
  border-color: var(--border-color);
  color: var(--fg-primary);
}

.example-pill.active {
  background: var(--bg-secondary);
  border-color: var(--accent);
  color: var(--fg-secondary);
}

/* Main Content */
.main {
  display: flex;
  flex: 1;
  overflow: hidden;
}

/* Panels */
.panel {
  flex: 1;
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

.panel-left {
  border-right: 1px solid var(--border-color);
}

.panel-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 10px 16px;
  background: var(--bg-tertiary);
  border-bottom: 1px solid var(--border-color);
  flex-shrink: 0;
}

.panel-title {
  font-size: 13px;
  font-weight: 600;
  color: var(--fg-muted);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.panel-actions {
  display: flex;
  gap: 8px;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 12px;
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  color: var(--fg-primary);
  font-size: 13px;
  font-weight: 500;
  cursor: pointer;
  transition: all var(--transition);
}

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

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

.btn-icon {
  font-size: 14px;
}

/* Editor */
.editor-container {
  flex: 1;
  overflow: hidden;
  position: relative;
}

.editor {
  width: 100%;
  height: 100%;
  padding: 16px;
  background: var(--bg-primary);
  border: none;
  color: var(--fg-primary);
  font-family: 'JetBrains Mono', 'Fira Code', 'Consolas', monospace;
  font-size: 14px;
  line-height: 1.6;
  resize: none;
  outline: none;
}

.editor::placeholder {
  color: var(--fg-muted);
}

/* Output */
.output-container {
  flex: 1;
  overflow: auto;
  background: var(--bg-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 20px;
}

.output {
  max-width: 100%;
  max-height: 100%;
}

.output svg {
  max-width: 100%;
  height: auto;
  display: block;
}

/* Error Display */
.error-container {
  display: none;
  padding: 16px;
  margin: 20px;
  background: rgba(247, 118, 142, 0.1);
  border: 1px solid var(--error);
  border-radius: var(--radius);
  color: var(--error);
  font-family: monospace;
  font-size: 13px;
  white-space: pre-wrap;
  word-break: break-word;
}

.error-container.visible {
  display: block;
}

/* Loading Indicator */
.loading {
  display: none;
  align-items: center;
  justify-content: center;
  padding: 40px;
  color: var(--fg-muted);
}

.loading.visible {
  display: flex;
}

.loading-spinner {
  width: 24px;
  height: 24px;
  border: 2px solid var(--border-color);
  border-top-color: var(--accent);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
  margin-right: 12px;
}

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

/* Empty State */
.empty-state {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 40px;
  color: var(--fg-muted);
  text-align: center;
}

.empty-state-icon {
  font-size: 48px;
  margin-bottom: 16px;
  opacity: 0.5;
}

/* Footer */
.footer {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 20px;
  padding: 12px 20px;
  background: var(--bg-secondary);
  border-top: 1px solid var(--border-color);
  font-size: 13px;
  color: var(--fg-muted);
  flex-shrink: 0;
}

.footer a {
  color: var(--fg-secondary);
  text-decoration: none;
  transition: color var(--transition);
}

.footer a:hover {
  color: var(--accent);
}

/* Toast Notifications */
.toast {
  position: fixed;
  bottom: 80px;
  left: 50%;
  transform: translateX(-50%) translateY(100px);
  padding: 12px 20px;
  background: var(--bg-secondary);
  border: 1px solid var(--success);
  border-radius: var(--radius);
  color: var(--success);
  font-size: 14px;
  opacity: 0;
  transition: all 0.3s ease;
  z-index: 1000;
}

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

/* Responsive */
@media (max-width: 768px) {
  .main {
    flex-direction: column;
  }

  .panel-left {
    border-right: none;
    border-bottom: 1px solid var(--border-color);
    max-height: 40vh;
  }

  .header {
    flex-direction: column;
    gap: 10px;
    align-items: stretch;
  }

  .logo {
    justify-content: center;
  }

  .category-tabs {
    justify-content: center;
  }

  .example-pills {
    justify-content: center;
  }

  .footer {
    flex-wrap: wrap;
    gap: 10px;
    text-align: center;
  }
}

/* Scrollbar Styling */
::-webkit-scrollbar {
  width: 8px;
  height: 8px;
}

::-webkit-scrollbar-track {
  background: var(--bg-primary);
}

::-webkit-scrollbar-thumb {
  background: var(--border-color);
  border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--fg-muted);
}

/* Focus Visible */
:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

/* Selection */
::selection {
  background: var(--accent);
  color: var(--bg-primary);
}

/* Font Awesome Icon Colors */
.logo-icon i {
  color: var(--fg-secondary);
}

.btn-icon i,
.theme-toggle i {
  color: var(--fg-primary);
}

.empty-state-icon i {
  color: var(--fg-muted);
}