/* QueryCraft Design System */

/* ===== Design Tokens ===== */
:root {
  /* Colors - Dark Theme */
  --color-bg-primary: #0d1117;
  --color-bg-secondary: #161b22;
  --color-bg-tertiary: #21262d;
  --color-bg-elevated: #1c2128;
  --color-bg-hover: #30363d;
  --color-bg-active: #484f58;
  
  /* Accent Colors */
  --color-accent-primary: #58a6ff;
  --color-accent-secondary: #388bfd;
  --color-accent-success: #3fb950;
  --color-accent-warning: #d29922;
  --color-accent-error: #f85149;
  --color-accent-purple: #a371f7;
  
  /* Text Colors */
  --color-text-primary: #e6edf3;
  --color-text-secondary: #8b949e;
  --color-text-tertiary: #6e7681;
  --color-text-placeholder: #484f58;
  --color-text-link: #58a6ff;
  
  /* Border Colors */
  --color-border-default: #30363d;
  --color-border-muted: #21262d;
  --color-border-focus: #58a6ff;
  
  /* Syntax Highlighting */
  --syntax-keyword: #ff7b72;
  --syntax-string: #a5d6ff;
  --syntax-number: #79c0ff;
  --syntax-function: #d2a8ff;
  --syntax-comment: #8b949e;
  --syntax-operator: #79c0ff;
  
  /* Typography */
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', 'SF Mono', Consolas, monospace;
  
  /* Font Sizes */
  --text-xs: 0.75rem;
  --text-sm: 0.875rem;
  --text-base: 1rem;
  --text-lg: 1.125rem;
  --text-xl: 1.25rem;
  --text-2xl: 1.5rem;
  
  /* Line Heights */
  --leading-tight: 1.25;
  --leading-normal: 1.5;
  --leading-relaxed: 1.75;
  
  /* Spacing Scale */
  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-5: 1.25rem;
  --space-6: 1.5rem;
  --space-8: 2rem;
  --space-10: 2.5rem;
  --space-12: 3rem;
  
  /* Border Radius */
  --radius-sm: 4px;
  --radius-md: 6px;
  --radius-lg: 8px;
  --radius-xl: 12px;
  
  /* Shadows */
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.3);
  --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.4);
  --shadow-glow: 0 0 20px rgba(88, 166, 255, 0.15);
  
  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-normal: 200ms ease;
  --transition-slow: 300ms ease;
  
  /* Layout */
  --sidebar-width: 280px;
  --ai-panel-width: 360px;
  --header-height: 48px;
  --tabs-height: 40px;
}

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

html {
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-sans);
  font-size: var(--text-sm);
  line-height: var(--leading-normal);
  color: var(--color-text-primary);
  background: var(--color-bg-primary);
  overflow: hidden;
  height: 100vh;
}

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

.app-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: var(--header-height);
  padding: 0 var(--space-4);
  background: var(--color-bg-secondary);
  border-bottom: 1px solid var(--color-border-default);
  -webkit-app-region: drag;
}

.app-header__left {
  display: flex;
  align-items: center;
  gap: var(--space-4);
  -webkit-app-region: no-drag;
}

.app-logo {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-weight: 600;
  color: var(--color-text-primary);
}

.app-logo__icon {
  width: 24px;
  height: 24px;
  background: linear-gradient(135deg, var(--color-accent-primary), var(--color-accent-purple));
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 14px;
}

.app-main {
  display: flex;
  flex: 1;
  overflow: hidden;
}

/* ===== Sidebar ===== */
.sidebar {
  width: var(--sidebar-width);
  background: var(--color-bg-secondary);
  border-right: 1px solid var(--color-border-default);
  display: flex;
  flex-direction: column;
}

.sidebar__header {
  padding: var(--space-3) var(--space-4);
  border-bottom: 1px solid var(--color-border-muted);
}

.sidebar__search {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-2) var(--space-3);
  background: var(--color-bg-tertiary);
  border: 1px solid var(--color-border-default);
  border-radius: var(--radius-md);
  color: var(--color-text-secondary);
  font-size: var(--text-sm);
}

.sidebar__search input {
  flex: 1;
  background: transparent;
  border: none;
  outline: none;
  color: var(--color-text-primary);
  font-size: var(--text-sm);
}

.sidebar__search input::placeholder {
  color: var(--color-text-placeholder);
}

.sidebar__content {
  flex: 1;
  overflow-y: auto;
  padding: var(--space-2) 0;
}

.sidebar__section {
  margin-bottom: var(--space-2);
}

.sidebar__section-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-2) var(--space-4);
  font-size: var(--text-xs);
  font-weight: 600;
  color: var(--color-text-tertiary);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.tree-item {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-1) var(--space-4);
  cursor: pointer;
  transition: background var(--transition-fast);
}

.tree-item:hover {
  background: var(--color-bg-hover);
}

.tree-item--active {
  background: var(--color-bg-tertiary);
  color: var(--color-accent-primary);
}

.tree-item__icon {
  width: 16px;
  height: 16px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-text-tertiary);
}

.tree-item__label {
  flex: 1;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.tree-item__badge {
  font-size: var(--text-xs);
  color: var(--color-text-tertiary);
}

/* ===== Main Content Area ===== */
.content {
  flex: 1;
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

/* Tabs */
.tabs {
  display: flex;
  align-items: center;
  height: var(--tabs-height);
  background: var(--color-bg-secondary);
  border-bottom: 1px solid var(--color-border-default);
  padding: 0 var(--space-2);
  gap: var(--space-1);
}

.tab {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-2) var(--space-3);
  background: transparent;
  border: none;
  border-radius: var(--radius-sm) var(--radius-sm) 0 0;
  color: var(--color-text-secondary);
  cursor: pointer;
  transition: all var(--transition-fast);
  font-size: var(--text-sm);
  position: relative;
}

.tab:hover {
  color: var(--color-text-primary);
  background: var(--color-bg-hover);
}

.tab--active {
  color: var(--color-text-primary);
  background: var(--color-bg-primary);
}

.tab--active::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: var(--color-accent-primary);
}

.tab__close {
  width: 16px;
  height: 16px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-sm);
  opacity: 0;
  transition: opacity var(--transition-fast);
}

.tab:hover .tab__close {
  opacity: 0.7;
}

.tab__close:hover {
  background: var(--color-bg-active);
  opacity: 1;
}

/* Editor Area */
.editor-container {
  flex: 1;
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

.editor-toolbar {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-2) var(--space-4);
  background: var(--color-bg-secondary);
  border-bottom: 1px solid var(--color-border-muted);
}

.toolbar-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  padding: var(--space-2) var(--space-3);
  background: var(--color-bg-tertiary);
  border: 1px solid var(--color-border-default);
  border-radius: var(--radius-md);
  color: var(--color-text-secondary);
  font-size: var(--text-sm);
  cursor: pointer;
  transition: all var(--transition-fast);
}

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

.toolbar-btn--primary {
  background: var(--color-accent-primary);
  border-color: var(--color-accent-primary);
  color: var(--color-bg-primary);
}

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

.toolbar-separator {
  width: 1px;
  height: 24px;
  background: var(--color-border-default);
  margin: 0 var(--space-2);
}

/* Code Editor */
.editor {
  flex: 1;
  position: relative;
  overflow: hidden;
  display: flex;
}

.editor__gutter {
  width: 48px;
  padding: var(--space-4) var(--space-2);
  background: var(--color-bg-secondary);
  border-right: 1px solid var(--color-border-muted);
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  line-height: 1.6;
  color: var(--color-text-tertiary);
  text-align: right;
  user-select: none;
}

.editor__code {
  flex: 1;
  padding: var(--space-4);
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  line-height: 1.6;
  overflow: auto;
  background: var(--color-bg-primary);
}

.editor__code:focus {
  outline: none;
}

/* Syntax Highlighting */
.sql-keyword { color: var(--syntax-keyword); font-weight: 500; }
.sql-string { color: var(--syntax-string); }
.sql-number { color: var(--syntax-number); }
.sql-function { color: var(--syntax-function); }
.sql-comment { color: var(--syntax-comment); font-style: italic; }
.sql-operator { color: var(--syntax-operator); }

/* Results Panel */
.results-panel {
  height: 240px;
  background: var(--color-bg-secondary);
  border-top: 1px solid var(--color-border-default);
  display: flex;
  flex-direction: column;
}

.results-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-2) var(--space-4);
  border-bottom: 1px solid var(--color-border-muted);
}

.results-tabs {
  display: flex;
  gap: var(--space-4);
}

.results-tab {
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
  background: none;
  border: none;
  cursor: pointer;
  padding: var(--space-1) 0;
  position: relative;
}

.results-tab--active {
  color: var(--color-accent-primary);
}

.results-tab--active::after {
  content: '';
  position: absolute;
  bottom: -9px;
  left: 0;
  right: 0;
  height: 2px;
  background: var(--color-accent-primary);
}

.results-info {
  font-size: var(--text-xs);
  color: var(--color-text-tertiary);
}

.results-content {
  flex: 1;
  overflow: auto;
}

/* Data Table */
.data-table {
  width: 100%;
  border-collapse: collapse;
  font-size: var(--text-sm);
  font-family: var(--font-mono);
}

.data-table th {
  position: sticky;
  top: 0;
  background: var(--color-bg-tertiary);
  padding: var(--space-2) var(--space-3);
  text-align: left;
  font-weight: 500;
  color: var(--color-text-secondary);
  border-bottom: 1px solid var(--color-border-default);
  white-space: nowrap;
}

.data-table td {
  padding: var(--space-2) var(--space-3);
  border-bottom: 1px solid var(--color-border-muted);
  white-space: nowrap;
}

.data-table tr:hover td {
  background: var(--color-bg-hover);
}

.data-null {
  color: var(--color-text-tertiary);
  font-style: italic;
}

/* ===== AI Panel ===== */
.ai-panel {
  width: var(--ai-panel-width);
  background: var(--color-bg-secondary);
  border-left: 1px solid var(--color-border-default);
  display: flex;
  flex-direction: column;
}

.ai-panel__header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-3) var(--space-4);
  border-bottom: 1px solid var(--color-border-default);
}

.ai-panel__title {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-weight: 600;
}

.ai-panel__title-icon {
  width: 20px;
  height: 20px;
  background: linear-gradient(135deg, var(--color-accent-purple), var(--color-accent-primary));
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 12px;
}

.ai-panel__content {
  flex: 1;
  overflow-y: auto;
  padding: var(--space-4);
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
}

/* AI Input */
.ai-input-container {
  padding: var(--space-4);
  border-top: 1px solid var(--color-border-default);
}

.ai-input {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.ai-input__field {
  display: flex;
  gap: var(--space-2);
}

.ai-input__textarea {
  flex: 1;
  min-height: 80px;
  padding: var(--space-3);
  background: var(--color-bg-tertiary);
  border: 1px solid var(--color-border-default);
  border-radius: var(--radius-md);
  color: var(--color-text-primary);
  font-family: var(--font-sans);
  font-size: var(--text-sm);
  resize: none;
  transition: border-color var(--transition-fast);
}

.ai-input__textarea:focus {
  outline: none;
  border-color: var(--color-accent-primary);
  box-shadow: var(--shadow-glow);
}

.ai-input__textarea::placeholder {
  color: var(--color-text-placeholder);
}

.ai-input__actions {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.ai-input__hints {
  display: flex;
  gap: var(--space-2);
}

.ai-hint-chip {
  padding: var(--space-1) var(--space-2);
  background: var(--color-bg-tertiary);
  border: 1px solid var(--color-border-default);
  border-radius: var(--radius-sm);
  font-size: var(--text-xs);
  color: var(--color-text-secondary);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.ai-hint-chip:hover {
  background: var(--color-bg-hover);
  border-color: var(--color-accent-primary);
  color: var(--color-accent-primary);
}

/* AI Messages */
.ai-message {
  padding: var(--space-3);
  border-radius: var(--radius-lg);
  font-size: var(--text-sm);
}

.ai-message--user {
  background: var(--color-bg-tertiary);
  margin-left: var(--space-8);
}

.ai-message--assistant {
  background: linear-gradient(135deg, rgba(88, 166, 255, 0.1), rgba(163, 113, 247, 0.1));
  border: 1px solid rgba(88, 166, 255, 0.2);
}

.ai-message__label {
  font-size: var(--text-xs);
  font-weight: 600;
  color: var(--color-text-tertiary);
  margin-bottom: var(--space-2);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.ai-message__content {
  line-height: var(--leading-relaxed);
}

.ai-message__code {
  margin-top: var(--space-3);
  background: var(--color-bg-primary);
  border-radius: var(--radius-md);
  overflow: hidden;
}

.ai-message__code-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-2) var(--space-3);
  background: var(--color-bg-tertiary);
  font-size: var(--text-xs);
  color: var(--color-text-secondary);
}

.ai-message__code-content {
  padding: var(--space-3);
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  line-height: 1.6;
  overflow-x: auto;
}

.ai-message__actions {
  display: flex;
  gap: var(--space-2);
  margin-top: var(--space-3);
}

.ai-action-btn {
  display: flex;
  align-items: center;
  gap: var(--space-1);
  padding: var(--space-1) var(--space-2);
  background: var(--color-bg-tertiary);
  border: 1px solid var(--color-border-default);
  border-radius: var(--radius-sm);
  color: var(--color-text-secondary);
  font-size: var(--text-xs);
  cursor: pointer;
  transition: all var(--transition-fast);
}

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

.ai-action-btn--primary {
  background: var(--color-accent-primary);
  border-color: var(--color-accent-primary);
  color: var(--color-bg-primary);
}

.ai-action-btn--primary:hover {
  background: var(--color-accent-secondary);
}

/* Optimization Card */
.optimization-card {
  padding: var(--space-3);
  background: rgba(63, 185, 80, 0.1);
  border: 1px solid rgba(63, 185, 80, 0.3);
  border-radius: var(--radius-lg);
}

.optimization-card__header {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-weight: 600;
  color: var(--color-accent-success);
  margin-bottom: var(--space-2);
}

.optimization-card__content {
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
  margin-bottom: var(--space-3);
}

.optimization-card__metric {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-2);
  background: var(--color-bg-primary);
  border-radius: var(--radius-md);
  margin-bottom: var(--space-2);
}

.metric-label {
  flex: 1;
  font-size: var(--text-xs);
  color: var(--color-text-tertiary);
}

.metric-before {
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  color: var(--color-accent-error);
  text-decoration: line-through;
}

.metric-arrow {
  color: var(--color-text-tertiary);
}

.metric-after {
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  color: var(--color-accent-success);
  font-weight: 600;
}

/* ===== Status Bar ===== */
.status-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 24px;
  padding: 0 var(--space-4);
  background: var(--color-bg-tertiary);
  border-top: 1px solid var(--color-border-default);
  font-size: var(--text-xs);
  color: var(--color-text-tertiary);
}

.status-bar__left,
.status-bar__right {
  display: flex;
  align-items: center;
  gap: var(--space-4);
}

.status-item {
  display: flex;
  align-items: center;
  gap: var(--space-1);
}

.status-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--color-accent-success);
}

.status-dot--warning {
  background: var(--color-accent-warning);
}

.status-dot--error {
  background: var(--color-accent-error);
}

/* ===== Loading States ===== */
.loading-dots {
  display: flex;
  gap: var(--space-1);
}

.loading-dots span {
  width: 6px;
  height: 6px;
  background: var(--color-accent-primary);
  border-radius: 50%;
  animation: loadingDot 1.4s infinite ease-in-out both;
}

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

@keyframes loadingDot {
  0%, 80%, 100% { transform: scale(0); opacity: 0.5; }
  40% { transform: scale(1); opacity: 1; }
}

/* ===== Empty States ===== */
.empty-state {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: var(--space-12);
  color: var(--color-text-tertiary);
  text-align: center;
}

.empty-state__icon {
  width: 48px;
  height: 48px;
  margin-bottom: var(--space-4);
  opacity: 0.5;
}

.empty-state__title {
  font-size: var(--text-lg);
  font-weight: 500;
  color: var(--color-text-secondary);
  margin-bottom: var(--space-2);
}

.empty-state__description {
  max-width: 280px;
  margin-bottom: var(--space-4);
}

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

::-webkit-scrollbar-track {
  background: transparent;
}

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

::-webkit-scrollbar-thumb:hover {
  background: var(--color-bg-active);
}

/* ===== Focus States ===== */
:focus-visible {
  outline: 2px solid var(--color-accent-primary);
  outline-offset: 2px;
}

/* ===== Selection ===== */
::selection {
  background: rgba(88, 166, 255, 0.3);
  color: var(--color-text-primary);
}

/* ===== Utility Classes ===== */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.truncate {
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}