/* ============================================
   RAGpy Design System
   Modern SaaS-grade UI Foundation
   ============================================ */

/* ----------------------------------------
   CSS Custom Properties (Design Tokens)
   ---------------------------------------- */
:root {
  /* Color Palette - Light Mode */
  --color-bg-primary: #F5F5F7;
  --color-bg-secondary: #FFFFFF;
  --color-bg-tertiary: #FAFAFA;
  --color-surface: #FFFFFF;
  --color-surface-elevated: #FFFFFF;

  --color-text-primary: #1A1A1C;
  --color-text-secondary: #6B7280;
  --color-text-tertiary: #9CA3AF;
  --color-text-inverse: #FFFFFF;

  --color-border: #E5E7EB;
  --color-border-light: #F3F4F6;
  --color-border-focus: #3B82F6;

  /* Brand Colors */
  --color-brand-primary: #3B82F6;
  --color-brand-primary-hover: #2563EB;
  --color-brand-primary-light: #EFF6FF;
  --color-brand-secondary: #8B5CF6;

  /* Semantic Colors */
  --color-success: #10B981;
  --color-success-light: #D1FAE5;
  --color-success-dark: #059669;

  --color-warning: #F59E0B;
  --color-warning-light: #FEF3C7;
  --color-warning-dark: #D97706;

  --color-error: #EF4444;
  --color-error-light: #FEE2E2;
  --color-error-dark: #DC2626;

  --color-info: #3B82F6;
  --color-info-light: #DBEAFE;

  /* Spacing Scale (4px base) */
  --space-0: 0;
  --space-1: 4px;
  --space-2: 8px;
  --space-3: 12px;
  --space-4: 16px;
  --space-5: 20px;
  --space-6: 24px;
  --space-8: 32px;
  --space-10: 40px;
  --space-12: 48px;
  --space-16: 64px;
  --space-20: 80px;

  /* Typography */
  --font-family-base: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  --font-family-mono: 'SF Mono', 'Fira Code', 'Fira Mono', 'Roboto Mono', monospace;

  /* Font Sizes */
  --text-xs: 0.75rem;      /* 12px */
  --text-sm: 0.875rem;     /* 14px */
  --text-base: 1rem;       /* 16px */
  --text-lg: 1.125rem;     /* 18px */
  --text-xl: 1.25rem;      /* 20px */
  --text-2xl: 1.75rem;     /* 28px */
  --text-3xl: 2rem;        /* 32px */

  /* Font Weights */
  --font-normal: 400;
  --font-medium: 500;
  --font-semibold: 600;
  --font-bold: 700;

  /* Line Heights */
  --leading-tight: 1.25;
  --leading-normal: 1.5;
  --leading-relaxed: 1.625;

  /* Letter Spacing */
  --tracking-tight: -0.025em;
  --tracking-normal: 0;
  --tracking-wide: 0.025em;

  /* Border Radius */
  --radius-sm: 6px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --radius-xl: 16px;
  --radius-full: 9999px;

  /* Shadows */
  --shadow-xs: 0 1px 2px rgba(0, 0, 0, 0.04);
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.06), 0 1px 2px rgba(0, 0, 0, 0.04);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.07), 0 2px 4px -1px rgba(0, 0, 0, 0.04);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.08), 0 4px 6px -2px rgba(0, 0, 0, 0.04);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.08), 0 10px 10px -5px rgba(0, 0, 0, 0.03);

  /* Focus Ring */
  --ring-color: rgba(59, 130, 246, 0.5);
  --ring-offset: 2px;

  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-base: 200ms ease;
  --transition-slow: 300ms ease;
  --transition-bounce: 300ms cubic-bezier(0.34, 1.56, 0.64, 1);

  /* 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: 240px;
  --sidebar-collapsed-width: 64px;
  --topbar-height: 56px;
  --content-max-width: 1280px;
}

/* ----------------------------------------
   Dark Mode
   ---------------------------------------- */
[data-theme="dark"],
.dark {
  --color-bg-primary: #050816;
  --color-bg-secondary: #0A0F1E;
  --color-bg-tertiary: #0F172A;
  --color-surface: #0F172A;
  --color-surface-elevated: #1E293B;

  --color-text-primary: #E5E7EB;
  --color-text-secondary: #9CA3AF;
  --color-text-tertiary: #6B7280;
  --color-text-inverse: #1A1A1C;

  --color-border: #1E293B;
  --color-border-light: #334155;
  --color-border-focus: #3B82F6;

  --color-brand-primary-light: rgba(59, 130, 246, 0.15);

  --color-success-light: rgba(16, 185, 129, 0.15);
  --color-warning-light: rgba(245, 158, 11, 0.15);
  --color-error-light: rgba(239, 68, 68, 0.15);
  --color-info-light: rgba(59, 130, 246, 0.15);

  --shadow-xs: 0 1px 2px rgba(0, 0, 0, 0.2);
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.3), 0 1px 2px rgba(0, 0, 0, 0.2);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.3), 0 2px 4px -1px rgba(0, 0, 0, 0.2);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.3), 0 4px 6px -2px rgba(0, 0, 0, 0.2);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.4), 0 10px 10px -5px rgba(0, 0, 0, 0.2);
}

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

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

body {
  font-family: var(--font-family-base);
  font-size: var(--text-base);
  font-weight: var(--font-normal);
  line-height: var(--leading-normal);
  color: var(--color-text-primary);
  background-color: var(--color-bg-primary);
  min-height: 100vh;
}

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

h1 {
  font-size: var(--text-3xl);
  font-weight: var(--font-bold);
}

h2 {
  font-size: var(--text-2xl);
}

h3 {
  font-size: var(--text-xl);
}

h4 {
  font-size: var(--text-lg);
  font-weight: var(--font-medium);
}

h5 {
  font-size: var(--text-base);
  font-weight: var(--font-medium);
}

h6 {
  font-size: var(--text-sm);
  font-weight: var(--font-medium);
  text-transform: uppercase;
  letter-spacing: var(--tracking-wide);
  color: var(--color-text-secondary);
}

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

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

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

small {
  font-size: var(--text-sm);
  color: var(--color-text-tertiary);
}

code {
  font-family: var(--font-family-mono);
  font-size: 0.9em;
  padding: 2px 6px;
  background: var(--color-bg-tertiary);
  border-radius: var(--radius-sm);
  color: var(--color-text-primary);
}

/* ----------------------------------------
   Utility Classes - Typography
   ---------------------------------------- */
.text-xs { font-size: var(--text-xs); }
.text-sm { font-size: var(--text-sm); }
.text-base { font-size: var(--text-base); }
.text-lg { font-size: var(--text-lg); }
.text-xl { font-size: var(--text-xl); }
.text-2xl { font-size: var(--text-2xl); }
.text-3xl { font-size: var(--text-3xl); }

.font-normal { font-weight: var(--font-normal); }
.font-medium { font-weight: var(--font-medium); }
.font-semibold { font-weight: var(--font-semibold); }
.font-bold { font-weight: var(--font-bold); }

.text-primary { color: var(--color-text-primary); }
.text-secondary { color: var(--color-text-secondary); }
.text-tertiary { color: var(--color-text-tertiary); }
.text-brand { color: var(--color-brand-primary); }
.text-success { color: var(--color-success); }
.text-warning { color: var(--color-warning); }
.text-error { color: var(--color-error); }

.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

/* ----------------------------------------
   Utility Classes - Spacing
   ---------------------------------------- */
.m-0 { margin: var(--space-0); }
.m-1 { margin: var(--space-1); }
.m-2 { margin: var(--space-2); }
.m-3 { margin: var(--space-3); }
.m-4 { margin: var(--space-4); }
.m-6 { margin: var(--space-6); }
.m-8 { margin: var(--space-8); }

.mt-0 { margin-top: var(--space-0); }
.mt-1 { margin-top: var(--space-1); }
.mt-2 { margin-top: var(--space-2); }
.mt-3 { margin-top: var(--space-3); }
.mt-4 { margin-top: var(--space-4); }
.mt-6 { margin-top: var(--space-6); }
.mt-8 { margin-top: var(--space-8); }

.mb-0 { margin-bottom: var(--space-0); }
.mb-1 { margin-bottom: var(--space-1); }
.mb-2 { margin-bottom: var(--space-2); }
.mb-3 { margin-bottom: var(--space-3); }
.mb-4 { margin-bottom: var(--space-4); }
.mb-6 { margin-bottom: var(--space-6); }
.mb-8 { margin-bottom: var(--space-8); }

.ml-0 { margin-left: var(--space-0); }
.ml-1 { margin-left: var(--space-1); }
.ml-2 { margin-left: var(--space-2); }
.ml-3 { margin-left: var(--space-3); }
.ml-4 { margin-left: var(--space-4); }

.mr-0 { margin-right: var(--space-0); }
.mr-1 { margin-right: var(--space-1); }
.mr-2 { margin-right: var(--space-2); }
.mr-3 { margin-right: var(--space-3); }
.mr-4 { margin-right: var(--space-4); }

.mx-auto { margin-left: auto; margin-right: auto; }

.p-0 { padding: var(--space-0); }
.p-1 { padding: var(--space-1); }
.p-2 { padding: var(--space-2); }
.p-3 { padding: var(--space-3); }
.p-4 { padding: var(--space-4); }
.p-6 { padding: var(--space-6); }
.p-8 { padding: var(--space-8); }

.px-0 { padding-left: var(--space-0); padding-right: var(--space-0); }
.px-2 { padding-left: var(--space-2); padding-right: var(--space-2); }
.px-3 { padding-left: var(--space-3); padding-right: var(--space-3); }
.px-4 { padding-left: var(--space-4); padding-right: var(--space-4); }
.px-6 { padding-left: var(--space-6); padding-right: var(--space-6); }
.px-8 { padding-left: var(--space-8); padding-right: var(--space-8); }

.py-0 { padding-top: var(--space-0); padding-bottom: var(--space-0); }
.py-2 { padding-top: var(--space-2); padding-bottom: var(--space-2); }
.py-3 { padding-top: var(--space-3); padding-bottom: var(--space-3); }
.py-4 { padding-top: var(--space-4); padding-bottom: var(--space-4); }
.py-6 { padding-top: var(--space-6); padding-bottom: var(--space-6); }
.py-8 { padding-top: var(--space-8); padding-bottom: var(--space-8); }

/* ----------------------------------------
   Utility Classes - Layout
   ---------------------------------------- */
.flex { display: flex; }
.inline-flex { display: inline-flex; }
.grid { display: grid; }
.block { display: block; }
.inline-block { display: inline-block; }
.hidden { display: none; }

.flex-row { flex-direction: row; }
.flex-col { flex-direction: column; }
.flex-wrap { flex-wrap: wrap; }
.flex-nowrap { flex-wrap: nowrap; }

.items-start { align-items: flex-start; }
.items-center { align-items: center; }
.items-end { align-items: flex-end; }
.items-stretch { align-items: stretch; }

.justify-start { justify-content: flex-start; }
.justify-center { justify-content: center; }
.justify-end { justify-content: flex-end; }
.justify-between { justify-content: space-between; }
.justify-around { justify-content: space-around; }

.gap-1 { gap: var(--space-1); }
.gap-2 { gap: var(--space-2); }
.gap-3 { gap: var(--space-3); }
.gap-4 { gap: var(--space-4); }
.gap-6 { gap: var(--space-6); }
.gap-8 { gap: var(--space-8); }

.flex-1 { flex: 1 1 0%; }
.flex-auto { flex: 1 1 auto; }
.flex-none { flex: none; }
.flex-shrink-0 { flex-shrink: 0; }
.flex-grow { flex-grow: 1; }

.w-full { width: 100%; }
.h-full { height: 100%; }
.min-h-screen { min-height: 100vh; }

.relative { position: relative; }
.absolute { position: absolute; }
.fixed { position: fixed; }
.sticky { position: sticky; }

.top-0 { top: 0; }
.right-0 { right: 0; }
.bottom-0 { bottom: 0; }
.left-0 { left: 0; }
.inset-0 { top: 0; right: 0; bottom: 0; left: 0; }

.overflow-hidden { overflow: hidden; }
.overflow-auto { overflow: auto; }
.overflow-y-auto { overflow-y: auto; }

/* ----------------------------------------
   Utility Classes - Visual
   ---------------------------------------- */
.bg-primary { background-color: var(--color-bg-primary); }
.bg-secondary { background-color: var(--color-bg-secondary); }
.bg-surface { background-color: var(--color-surface); }
.bg-brand { background-color: var(--color-brand-primary); }
.bg-success { background-color: var(--color-success); }
.bg-warning { background-color: var(--color-warning); }
.bg-error { background-color: var(--color-error); }

.border { border: 1px solid var(--color-border); }
.border-t { border-top: 1px solid var(--color-border); }
.border-b { border-bottom: 1px solid var(--color-border); }
.border-l { border-left: 1px solid var(--color-border); }
.border-r { border-right: 1px solid var(--color-border); }
.border-0 { border: none; }

.rounded-sm { border-radius: var(--radius-sm); }
.rounded { border-radius: var(--radius-md); }
.rounded-lg { border-radius: var(--radius-lg); }
.rounded-xl { border-radius: var(--radius-xl); }
.rounded-full { border-radius: var(--radius-full); }

.shadow-xs { box-shadow: var(--shadow-xs); }
.shadow-sm { box-shadow: var(--shadow-sm); }
.shadow { box-shadow: var(--shadow-md); }
.shadow-lg { box-shadow: var(--shadow-lg); }
.shadow-xl { box-shadow: var(--shadow-xl); }
.shadow-none { box-shadow: none; }

.opacity-0 { opacity: 0; }
.opacity-50 { opacity: 0.5; }
.opacity-75 { opacity: 0.75; }
.opacity-100 { opacity: 1; }

/* ----------------------------------------
   Animations & Transitions
   ---------------------------------------- */
.transition {
  transition-property: color, background-color, border-color, box-shadow, transform, opacity;
  transition-timing-function: ease;
  transition-duration: 200ms;
}

.transition-fast { transition-duration: 150ms; }
.transition-slow { transition-duration: 300ms; }

.hover\:scale:hover {
  transform: scale(1.02);
}

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

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

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

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

@keyframes slideInRight {
  from {
    opacity: 0;
    transform: translateX(20px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

@keyframes slideInLeft {
  from {
    opacity: 0;
    transform: translateX(-20px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

@keyframes scaleIn {
  from {
    opacity: 0;
    transform: scale(0.95);
  }
  to {
    opacity: 1;
    transform: scale(1);
  }
}

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

@keyframes shimmer {
  0% { background-position: -200% 0; }
  100% { background-position: 200% 0; }
}

@keyframes spin {
  from { transform: rotate(0deg); }
  to { transform: rotate(360deg); }
}

.animate-fade-in { animation: fadeIn var(--transition-base) ease-out; }
.animate-fade-in-up { animation: fadeInUp var(--transition-slow) ease-out; }
.animate-fade-in-down { animation: fadeInDown var(--transition-slow) ease-out; }
.animate-slide-in-right { animation: slideInRight var(--transition-slow) ease-out; }
.animate-slide-in-left { animation: slideInLeft var(--transition-slow) ease-out; }
.animate-scale-in { animation: scaleIn var(--transition-base) ease-out; }
.animate-pulse { animation: pulse 2s ease-in-out infinite; }
.animate-spin { animation: spin 1s linear infinite; }

/* Skeleton Loader */
.skeleton {
  background: linear-gradient(
    90deg,
    var(--color-bg-tertiary) 25%,
    var(--color-border-light) 50%,
    var(--color-bg-tertiary) 75%
  );
  background-size: 200% 100%;
  animation: shimmer 1.5s infinite;
  border-radius: var(--radius-sm);
}

.skeleton-text {
  height: 1em;
  margin-bottom: 0.5em;
}

.skeleton-text:last-child {
  width: 60%;
}

.skeleton-circle {
  border-radius: 50%;
}

.skeleton-avatar {
  width: 40px;
  height: 40px;
  border-radius: 50%;
}

.skeleton-card {
  height: 120px;
  border-radius: var(--radius-lg);
}

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

.focus-ring:focus-visible {
  outline: none;
  box-shadow: 0 0 0 var(--ring-offset) var(--color-bg-primary),
              0 0 0 calc(var(--ring-offset) + 2px) var(--ring-color);
}

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

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

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

::-webkit-scrollbar-thumb:hover {
  background: var(--color-text-tertiary);
}

/* Firefox */
* {
  scrollbar-width: thin;
  scrollbar-color: var(--color-border) transparent;
}

/* ----------------------------------------
   Selection
   ---------------------------------------- */
::selection {
  background: var(--color-brand-primary);
  color: white;
}

/* ----------------------------------------
   Screen Reader Only
   ---------------------------------------- */
.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;
}