/**
 * Bridge AI OS - Main Stylesheet
 * Production-ready CSS with dark theme, accessibility, and responsive design
 */

/* ============================================
   CSS CUSTOM PROPERTIES (VARIABLES)
   ============================================ */

:root {
  /* Colors - Primary */
  --color-primary-50: #eef2ff;
  --color-primary-100: #e0e7ff;
  --color-primary-200: #c7d2fe;
  --color-primary-300: #a5b4fc;
  --color-primary-400: #818cf8;
  --color-primary-500: #6366f1;
  --color-primary-600: #4f46e5;
  --color-primary-700: #4338ca;
  --color-primary-800: #3730a3;
  --color-primary-900: #312e81;
  
  /* Colors - Secondary */
  --color-secondary-50: #f5f3ff;
  --color-secondary-100: #ede9fe;
  --color-secondary-200: #ddd6fe;
  --color-secondary-300: #c4b5fd;
  --color-secondary-400: #a78bfa;
  --color-secondary-500: #8b5cf6;
  --color-secondary-600: #7c3aed;
  --color-secondary-700: #6d28d9;
  --color-secondary-800: #5b21b6;
  --color-secondary-900: #4c1d95;
  
  /* Colors - Semantic */
  --color-success-50: #ecfdf5;
  --color-success-100: #d1fae5;
  --color-success-500: #10b981;
  --color-success-600: #059669;
  --color-success-700: #047857;
  
  --color-warning-50: #fffbeb;
  --color-warning-100: #fef3c7;
  --color-warning-500: #f59e0b;
  --color-warning-600: #d97706;
  --color-warning-700: #b45309;
  
  --color-error-50: #fef2f2;
  --color-error-100: #fee2e2;
  --color-error-500: #ef4444;
  --color-error-600: #dc2626;
  --color-error-700: #b91c1c;
  
  --color-info-50: #eff6ff;
  --color-info-100: #dbeafe;
  --color-info-500: #3b82f6;
  --color-info-600: #2563eb;
  --color-info-700: #1d4ed8;
  
  /* Dark Theme Colors */
  --bg-primary: #0f0f23;
  --bg-secondary: #1a1a2e;
  --bg-tertiary: #16213e;
  --bg-elevated: #1e1e3f;
  --bg-hover: #252550;
  --bg-active: #2d2d5a;
  
  --text-primary: #f8fafc;
  --text-secondary: #94a3b8;
  --text-tertiary: #64748b;
  --text-muted: #475569;
  
  --border-color: #2d2d5a;
  --border-color-light: #3d3d6a;
  
  /* Spacing */
  --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;
  --space-16: 4rem;
  
  /* Typography */
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', Consolas, monospace;
  
  --text-xs: 0.75rem;
  --text-sm: 0.875rem;
  --text-base: 1rem;
  --text-lg: 1.125rem;
  --text-xl: 1.25rem;
  --text-2xl: 1.5rem;
  --text-3xl: 1.875rem;
  --text-4xl: 2.25rem;
  
  --font-light: 300;
  --font-normal: 400;
  --font-medium: 500;
  --font-semibold: 600;
  --font-bold: 700;
  
  --leading-tight: 1.25;
  --leading-normal: 1.5;
  --leading-relaxed: 1.625;
  
  /* Border Radius */
  --radius-sm: 0.25rem;
  --radius-md: 0.375rem;
  --radius-lg: 0.5rem;
  --radius-xl: 0.75rem;
  --radius-2xl: 1rem;
  --radius-full: 9999px;
  
  /* Shadows */
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
  --shadow-glow: 0 0 20px rgba(99, 102, 241, 0.3);
  
  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-normal: 200ms ease;
  --transition-slow: 300ms ease;
  
  /* Z-Index Scale */
  --z-dropdown: 100;
  --z-sticky: 200;
  --z-fixed: 300;
  --z-modal-backdrop: 400;
  --z-modal: 500;
  --z-popover: 600;
  --z-tooltip: 700;
  --z-toast: 800;
  
  /* Layout */
  --sidebar-width: 260px;
  --sidebar-collapsed-width: 72px;
  --top-bar-height: 64px;
}

/* Light Theme */
.light-theme {
  --bg-primary: #ffffff;
  --bg-secondary: #f8fafc;
  --bg-tertiary: #f1f5f9;
  --bg-elevated: #ffffff;
  --bg-hover: #f1f5f9;
  --bg-active: #e2e8f0;
  
  --text-primary: #0f172a;
  --text-secondary: #475569;
  --text-tertiary: #64748b;
  --text-muted: #94a3b8;
  
  --border-color: #e2e8f0;
  --border-color-light: #cbd5e1;
}

/* ============================================
   RESET & BASE STYLES
   ============================================ */

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-sans);
  font-size: var(--text-base);
  font-weight: var(--font-normal);
  line-height: var(--leading-normal);
  color: var(--text-primary);
  background-color: var(--bg-primary);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

/* Focus Styles for Accessibility */
:focus-visible {
  outline: 2px solid var(--color-primary-500);
  outline-offset: 2px;
}

:focus:not(:focus-visible) {
  outline: none;
}

/* Skip Link */
.skip-link {
  position: absolute;
  top: -40px;
  left: 0;
  background: var(--color-primary-600);
  color: white;
  padding: var(--space-2) var(--space-4);
  z-index: var(--z-toast);
  transition: top var(--transition-fast);
}

.skip-link:focus {
  top: 0;
}

/* ============================================
   TYPOGRAPHY
   ============================================ */

h1, h2, h3, h4, h5, h6 {
  font-weight: var(--font-semibold);
  line-height: var(--leading-tight);
  color: var(--text-primary);
}

h1 { font-size: var(--text-4xl); }
h2 { font-size: var(--text-3xl); }
h3 { font-size: var(--text-2xl); }
h4 { font-size: var(--text-xl); }
h5 { font-size: var(--text-lg); }
h6 { font-size: var(--text-base); }

p {
  margin-bottom: var(--space-4);
  color: var(--text-secondary);
}

a {
  color: var(--color-primary-400);
  text-decoration: none;
  transition: color var(--transition-fast);
}

a:hover {
  color: var(--color-primary-300);
}

code, pre {
  font-family: var(--font-mono);
  font-size: var(--text-sm);
}

code {
  background: var(--bg-tertiary);
  padding: var(--space-1) var(--space-2);
  border-radius: var(--radius-sm);
}

pre {
  background: var(--bg-tertiary);
  padding: var(--space-4);
  border-radius: var(--radius-lg);
  overflow-x: auto;
}

pre code {
  background: none;
  padding: 0;
}

/* ============================================
   LOADING SCREEN
   ============================================ */

.loading-screen {
  position: fixed;
  inset: 0;
  background: var(--bg-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: var(--z-toast);
  transition: opacity var(--transition-slow), visibility var(--transition-slow);
}

.loading-screen.hidden {
  opacity: 0;
  visibility: hidden;
}

.loading-content {
  text-align: center;
}

.loading-logo {
  width: 80px;
  height: 80px;
  margin: 0 auto var(--space-6);
  animation: pulse 2s ease-in-out infinite;
}

.loading-logo .logo-svg {
  width: 100%;
  height: 100%;
}

.loading-text {
  font-size: var(--text-xl);
  font-weight: var(--font-semibold);
  color: var(--text-primary);
  margin-bottom: var(--space-6);
}

.loading-spinner {
  width: 40px;
  height: 40px;
  border: 3px solid var(--border-color);
  border-top-color: var(--color-primary-500);
  border-radius: 50%;
  margin: 0 auto;
  animation: spin 1s linear infinite;
}

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

@keyframes pulse {
  0%, 100% { transform: scale(1); opacity: 1; }
  50% { transform: scale(1.05); opacity: 0.8; }
}

/* ============================================
   APP CONTAINER
   ============================================ */

.app-container {
  display: flex;
  min-height: 100vh;
}

/* ============================================
   SIDEBAR
   ============================================ */

.sidebar {
  width: var(--sidebar-width);
  background: var(--bg-secondary);
  border-right: 1px solid var(--border-color);
  display: flex;
  flex-direction: column;
  position: fixed;
  top: 0;
  left: 0;
  bottom: 0;
  z-index: var(--z-fixed);
  transition: width var(--transition-normal), transform var(--transition-normal);
}

.sidebar.collapsed {
  width: var(--sidebar-collapsed-width);
}

.sidebar.collapsed .logo-text,
.sidebar.collapsed .nav-link span,
.sidebar.collapsed .user-info,
.sidebar.collapsed .nav-badge {
  opacity: 0;
  visibility: hidden;
}

.sidebar-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-4) var(--space-4);
  border-bottom: 1px solid var(--border-color);
  min-height: var(--top-bar-height);
}

.logo {
  display: flex;
  align-items: center;
  gap: var(--space-3);
}

.logo .logo-svg {
  width: 36px;
  height: 36px;
  flex-shrink: 0;
}

.logo-text {
  font-size: var(--text-lg);
  font-weight: var(--font-semibold);
  color: var(--text-primary);
  white-space: nowrap;
  transition: opacity var(--transition-fast), visibility var(--transition-fast);
}

.sidebar-toggle {
  background: none;
  border: none;
  color: var(--text-secondary);
  cursor: pointer;
  padding: var(--space-2);
  border-radius: var(--radius-md);
  transition: background-color var(--transition-fast), color var(--transition-fast);
}

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

.sidebar-toggle svg {
  width: 20px;
  height: 20px;
}

/* Navigation */
.sidebar-nav {
  flex: 1;
  overflow-y: auto;
  padding: var(--space-4) 0;
}

.nav-list {
  list-style: none;
  padding: 0 var(--space-3);
}

.nav-item {
  margin-bottom: var(--space-1);
}

.nav-link {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-3) var(--space-3);
  color: var(--text-secondary);
  border-radius: var(--radius-lg);
  transition: background-color var(--transition-fast), color var(--transition-fast);
  position: relative;
}

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

.nav-link.active {
  background: var(--color-primary-600);
  color: white;
}

.nav-link.active::before {
  content: '';
  position: absolute;
  left: -12px;
  top: 50%;
  transform: translateY(-50%);
  width: 4px;
  height: 24px;
  background: var(--color-primary-400);
  border-radius: var(--radius-full);
}

.nav-link svg {
  width: 20px;
  height: 20px;
  flex-shrink: 0;
}

.nav-link span {
  white-space: nowrap;
  transition: opacity var(--transition-fast), visibility var(--transition-fast);
}

.nav-badge {
  margin-left: auto;
  background: var(--color-primary-600);
  color: white;
  font-size: var(--text-xs);
  font-weight: var(--font-medium);
  padding: var(--space-1) var(--space-2);
  border-radius: var(--radius-full);
  min-width: 20px;
  text-align: center;
  transition: opacity var(--transition-fast), visibility var(--transition-fast);
}

.nav-divider {
  height: 1px;
  background: var(--border-color);
  margin: var(--space-4) var(--space-4);
}

/* Sidebar Footer */
.sidebar-footer {
  padding: var(--space-4);
  border-top: 1px solid var(--border-color);
}

.user-profile {
  display: flex;
  align-items: center;
  gap: var(--space-3);
}

.user-avatar {
  width: 40px;
  height: 40px;
  background: linear-gradient(135deg, var(--color-primary-500), var(--color-secondary-500));
  border-radius: var(--radius-full);
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-weight: var(--font-semibold);
  flex-shrink: 0;
}

.user-info {
  flex: 1;
  min-width: 0;
  transition: opacity var(--transition-fast), visibility var(--transition-fast);
}

.user-name {
  display: block;
  font-weight: var(--font-medium);
  color: var(--text-primary);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.user-tier {
  display: block;
  font-size: var(--text-xs);
  color: var(--text-tertiary);
}

.user-menu-btn {
  background: none;
  border: none;
  color: var(--text-secondary);
  cursor: pointer;
  padding: var(--space-1);
  border-radius: var(--radius-md);
  transition: background-color var(--transition-fast), color var(--transition-fast);
}

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

.user-menu-btn svg {
  width: 16px;
  height: 16px;
}

/* ============================================
   MAIN CONTENT
   ============================================ */

.main-content {
  flex: 1;
  margin-left: var(--sidebar-width);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  transition: margin-left var(--transition-normal);
}

.sidebar.collapsed ~ .main-content {
  margin-left: var(--sidebar-collapsed-width);
}

/* ============================================
   TOP BAR
   ============================================ */

.top-bar {
  height: var(--top-bar-height);
  background: var(--bg-secondary);
  border-bottom: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 var(--space-6);
  position: sticky;
  top: 0;
  z-index: var(--z-sticky);
}

.top-bar-left {
  display: flex;
  align-items: center;
  gap: var(--space-4);
}

.mobile-menu-btn {
  display: none;
  background: none;
  border: none;
  color: var(--text-secondary);
  cursor: pointer;
  padding: var(--space-2);
  border-radius: var(--radius-md);
}

.mobile-menu-btn svg {
  width: 24px;
  height: 24px;
}

.breadcrumb {
  font-size: var(--text-sm);
  color: var(--text-secondary);
}

.breadcrumb span {
  color: var(--text-primary);
  font-weight: var(--font-medium);
}

.top-bar-center {
  flex: 1;
  max-width: 480px;
  margin: 0 var(--space-8);
}

.search-container {
  position: relative;
  width: 100%;
}

.search-icon {
  position: absolute;
  left: var(--space-3);
  top: 50%;
  transform: translateY(-50%);
  width: 18px;
  height: 18px;
  color: var(--text-tertiary);
  pointer-events: none;
}

.search-input {
  width: 100%;
  background: var(--bg-tertiary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: var(--space-2) var(--space-4) var(--space-2) var(--space-10);
  font-size: var(--text-sm);
  color: var(--text-primary);
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

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

.search-input:focus {
  border-color: var(--color-primary-500);
  box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

.search-shortcut {
  position: absolute;
  right: var(--space-3);
  top: 50%;
  transform: translateY(-50%);
  background: var(--bg-elevated);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  padding: var(--space-1) var(--space-2);
  font-size: var(--text-xs);
  color: var(--text-tertiary);
  font-family: var(--font-mono);
}

.top-bar-right {
  display: flex;
  align-items: center;
  gap: var(--space-3);
}

.top-bar-btn {
  position: relative;
  background: none;
  border: none;
  color: var(--text-secondary);
  cursor: pointer;
  padding: var(--space-2);
  border-radius: var(--radius-lg);
  transition: background-color var(--transition-fast), color var(--transition-fast);
}

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

.top-bar-btn svg {
  width: 20px;
  height: 20px;
}

.icon-moon {
  display: none;
}

.light-theme .icon-sun {
  display: none;
}

.light-theme .icon-moon {
  display: block;
}

.notification-badge {
  position: absolute;
  top: 2px;
  right: 2px;
  background: var(--color-error-500);
  color: white;
  font-size: 10px;
  font-weight: var(--font-bold);
  min-width: 16px;
  height: 16px;
  border-radius: var(--radius-full);
  display: flex;
  align-items: center;
  justify-content: center;
}

.status-indicator {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-2) var(--space-3);
  background: var(--bg-tertiary);
  border-radius: var(--radius-full);
}

.status-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  animation: pulse-dot 2s ease-in-out infinite;
}

.status-dot.status-healthy {
  background: var(--color-success-500);
}

.status-dot.status-degraded {
  background: var(--color-warning-500);
}

.status-dot.status-unhealthy {
  background: var(--color-error-500);
}

@keyframes pulse-dot {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.5; }
}

.status-text {
  font-size: var(--text-xs);
  color: var(--text-secondary);
}

/* ============================================
   PAGE CONTENT
   ============================================ */

.page-content {
  flex: 1;
  padding: var(--space-6);
  overflow-y: auto;
}

.page {
  display: none;
  animation: fadeIn var(--transition-normal);
}

.page.active {
  display: block;
}

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

.page-header {
  margin-bottom: var(--space-8);
  display: flex;
  flex-wrap: wrap;
  align-items: flex-start;
  justify-content: space-between;
  gap: var(--space-4);
}

.page-title {
  font-size: var(--text-3xl);
  font-weight: var(--font-bold);
  color: var(--text-primary);
  margin-bottom: var(--space-1);
}

.page-subtitle {
  font-size: var(--text-base);
  color: var(--text-secondary);
  margin: 0;
}

/* ============================================
   RESPONSIVE DESIGN
   ============================================ */

@media (max-width: 1024px) {
  .sidebar {
    transform: translateX(-100%);
  }
  
  .sidebar.open {
    transform: translateX(0);
  }
  
  .main-content {
    margin-left: 0;
  }
  
  .sidebar.collapsed ~ .main-content {
    margin-left: 0;
  }
  
  .mobile-menu-btn {
    display: block;
  }
  
  .top-bar-center {
    display: none;
  }
}

@media (max-width: 768px) {
  .top-bar {
    padding: 0 var(--space-4);
  }
  
  .page-content {
    padding: var(--space-4);
  }
  
  .page-title {
    font-size: var(--text-2xl);
  }
  
  .status-indicator .status-text {
    display: none;
  }
}

@media (max-width: 480px) {
  .page-header {
    flex-direction: column;
    align-items: stretch;
  }
  
  .top-bar-right {
    gap: var(--space-2);
  }
}

/* ============================================
   PRINT STYLES
   ============================================ */

@media print {
  .sidebar,
  .top-bar,
  .skip-link {
    display: none !important;
  }
  
  .main-content {
    margin-left: 0 !important;
  }
  
  .page-content {
    padding: 0;
  }
}

/* ============================================
   REDUCED MOTION
   ============================================ */

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

/* ============================================
   HIGH CONTRAST MODE
   ============================================ */

@media (prefers-contrast: high) {
  :root {
    --border-color: var(--text-primary);
    --border-color-light: var(--text-primary);
  }
  
  .nav-link.active {
    outline: 2px solid white;
  }
}

/* ============================================
   SVG / DIAGRAM SIZING (prevent too-big SVGs)
   ============================================ */

img[src*=".svg"],
.svg-constrained,
.diagram-svg,
.flow-diagram svg,
figure img[src*=".svg"] {
  max-width: 100%;
  height: auto;
}

/* Flow/diagram SVGs (viewBox 600x200 or similar) — cap height so they don't dominate */
.diagram-svg,
.flow-diagram svg,
svg[viewBox*="600"][viewBox*="200"] {
  max-height: 220px;
  width: auto;
}