/**
 * PILLAR Design System
 * Version: 1.0.0
 *
 * A comprehensive design system for consistent UI across all PILLAR pages.
 * Includes dark mode support, component styles, and utility classes.
 */

/* ============================================
   1. CSS CUSTOM PROPERTIES (Design Tokens)
   ============================================ */

:root {
  /* === Brand Colors === */
  --color-primary: #8B00FF;
  --color-primary-dark: #6B00CC;
  --color-primary-darker: #5500AA;
  --color-primary-light: #A855F7;
  --color-primary-glow: rgba(139, 0, 255, 0.15);
  --color-primary-glow-strong: rgba(139, 0, 255, 0.25);

  /* === Semantic Colors === */
  --color-success: #10B981;
  --color-success-light: rgba(16, 185, 129, 0.1);
  --color-warning: #F59E0B;
  --color-warning-light: rgba(245, 158, 11, 0.1);
  --color-error: #EF4444;
  --color-error-light: rgba(239, 68, 68, 0.1);
  --color-info: #3B82F6;
  --color-info-light: rgba(59, 130, 246, 0.1);

  /* === Neutral Colors (Light Mode) === */
  --color-black: #000000;
  --color-black-soft: #1a1a1a;
  --color-gray-900: #111827;
  --color-gray-800: #1F2937;
  --color-gray-700: #374151;
  --color-gray-600: #4B5563;
  --color-gray-500: #6B7280;
  --color-gray-400: #9CA3AF;
  --color-gray-300: #D1D5DB;
  --color-gray-200: #E5E7EB;
  --color-gray-100: #F3F4F6;
  --color-gray-50: #F9FAFB;
  --color-white: #FFFFFF;
  --color-off-white: #FAFAFA;

  /* === Theme Colors (Light Mode Default) === */
  --bg-primary: var(--color-white);
  --bg-secondary: var(--color-off-white);
  --bg-tertiary: var(--color-gray-100);
  --bg-inverse: var(--color-black);

  --text-primary: var(--color-black);
  --text-secondary: var(--color-gray-600);
  --text-tertiary: var(--color-gray-400);
  --text-inverse: var(--color-white);
  --text-link: var(--color-primary);

  --border-color: var(--color-gray-200);
  --border-color-strong: var(--color-gray-300);

  /* === Shadows (Light Mode) === */
  --shadow-sm: 0 1px 2px 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-2xl: 0 25px 50px -12px rgba(0, 0, 0, 0.25);
  --shadow-purple: 0 10px 40px var(--color-primary-glow);
  --shadow-purple-lg: 0 20px 60px var(--color-primary-glow-strong);

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

  --font-size-xs: 0.75rem;     /* 12px */
  --font-size-sm: 0.875rem;    /* 14px */
  --font-size-base: 1rem;      /* 16px */
  --font-size-lg: 1.125rem;    /* 18px */
  --font-size-xl: 1.25rem;     /* 20px */
  --font-size-2xl: 1.5rem;     /* 24px */
  --font-size-3xl: 1.875rem;   /* 30px */
  --font-size-4xl: 2.25rem;    /* 36px */
  --font-size-5xl: 3rem;       /* 48px */
  --font-size-6xl: 3.75rem;    /* 60px */

  --font-weight-normal: 400;
  --font-weight-medium: 500;
  --font-weight-semibold: 600;
  --font-weight-bold: 700;
  --font-weight-extrabold: 800;
  --font-weight-black: 900;

  --line-height-tight: 1.25;
  --line-height-snug: 1.375;
  --line-height-normal: 1.5;
  --line-height-relaxed: 1.625;
  --line-height-loose: 1.7;

  --letter-spacing-tighter: -0.05em;
  --letter-spacing-tight: -0.025em;
  --letter-spacing-normal: 0;
  --letter-spacing-wide: 0.025em;
  --letter-spacing-wider: 0.05em;
  --letter-spacing-widest: 0.1em;

  /* === Spacing === */
  --space-0: 0;
  --space-1: 0.25rem;   /* 4px */
  --space-2: 0.5rem;    /* 8px */
  --space-3: 0.75rem;   /* 12px */
  --space-4: 1rem;      /* 16px */
  --space-5: 1.25rem;   /* 20px */
  --space-6: 1.5rem;    /* 24px */
  --space-8: 2rem;      /* 32px */
  --space-10: 2.5rem;   /* 40px */
  --space-12: 3rem;     /* 48px */
  --space-16: 4rem;     /* 64px */
  --space-20: 5rem;     /* 80px */
  --space-24: 6rem;     /* 96px */

  /* === Border Radius === */
  --radius-none: 0;
  --radius-sm: 0.125rem;   /* 2px */
  --radius-base: 0.25rem;  /* 4px */
  --radius-md: 0.375rem;   /* 6px */
  --radius-lg: 0.5rem;     /* 8px */
  --radius-xl: 0.75rem;    /* 12px */
  --radius-2xl: 1rem;      /* 16px */
  --radius-3xl: 1.5rem;    /* 24px */
  --radius-full: 9999px;

  /* === Transitions === */
  --transition-fast: 150ms ease;
  --transition-base: 200ms ease;
  --transition-slow: 300ms ease;
  --transition-slower: 500ms ease;

  /* === Z-Index Scale === */
  --z-behind: -1;
  --z-base: 0;
  --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;
  --z-nav: 1000;

  /* === Layout === */
  --nav-height: 64px;
  --container-max: 1200px;
  --container-sm: 640px;
  --container-md: 768px;
  --container-lg: 1024px;
  --container-xl: 1280px;
}

/* ============================================
   2. DARK MODE
   ============================================ */

[data-theme="dark"],
.dark-mode {
  --bg-primary: #0a0a0f;
  --bg-secondary: #111118;
  --bg-tertiary: #1a1a24;
  --bg-inverse: var(--color-white);

  --text-primary: var(--color-white);
  --text-secondary: rgba(255, 255, 255, 0.7);
  --text-tertiary: rgba(255, 255, 255, 0.4);
  --text-inverse: var(--color-black);

  --border-color: rgba(255, 255, 255, 0.1);
  --border-color-strong: rgba(255, 255, 255, 0.2);

  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.5);
  --shadow-xl: 0 20px 25px rgba(0, 0, 0, 0.6);
  --shadow-2xl: 0 25px 50px rgba(0, 0, 0, 0.7);
}

/* System preference detection */
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg-primary: #0a0a0f;
    --bg-secondary: #111118;
    --bg-tertiary: #1a1a24;
    --bg-inverse: var(--color-white);

    --text-primary: var(--color-white);
    --text-secondary: rgba(255, 255, 255, 0.7);
    --text-tertiary: rgba(255, 255, 255, 0.4);
    --text-inverse: var(--color-black);

    --border-color: rgba(255, 255, 255, 0.1);
    --border-color-strong: rgba(255, 255, 255, 0.2);
  }
}

/* ============================================
   3. BASE STYLES
   ============================================ */

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

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
  overflow-x: hidden;
}

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

/* ============================================
   4. TYPOGRAPHY COMPONENTS
   ============================================ */

.heading-1 {
  font-size: clamp(2.5rem, 5vw, 4.5rem);
  font-weight: var(--font-weight-black);
  line-height: var(--line-height-tight);
  letter-spacing: var(--letter-spacing-tighter);
}

.heading-2 {
  font-size: clamp(2rem, 4vw, 3rem);
  font-weight: var(--font-weight-extrabold);
  line-height: var(--line-height-tight);
  letter-spacing: var(--letter-spacing-tight);
}

.heading-3 {
  font-size: clamp(1.5rem, 3vw, 2rem);
  font-weight: var(--font-weight-bold);
  line-height: var(--line-height-snug);
}

.heading-4 {
  font-size: var(--font-size-xl);
  font-weight: var(--font-weight-bold);
  line-height: var(--line-height-snug);
}

.heading-5 {
  font-size: var(--font-size-lg);
  font-weight: var(--font-weight-semibold);
  line-height: var(--line-height-normal);
}

.text-gradient {
  background: linear-gradient(135deg, var(--text-primary) 0%, var(--color-primary) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.text-muted {
  color: var(--text-secondary);
}

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

.text-uppercase {
  text-transform: uppercase;
  letter-spacing: var(--letter-spacing-wider);
}

/* ============================================
   5. BUTTON COMPONENTS
   ============================================ */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-6);
  font-family: inherit;
  font-size: var(--font-size-base);
  font-weight: var(--font-weight-semibold);
  line-height: 1;
  text-decoration: none;
  border: 2px solid transparent;
  border-radius: var(--radius-lg);
  cursor: pointer;
  transition: all var(--transition-base);
  min-height: 48px;
}

.btn:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

.btn-primary {
  background: var(--color-primary);
  color: var(--color-white);
  box-shadow: var(--shadow-purple);
}

.btn-primary:hover {
  background: var(--color-primary-dark);
  transform: translateY(-2px);
  box-shadow: var(--shadow-purple-lg);
}

.btn-secondary {
  background: transparent;
  color: var(--color-primary);
  border-color: var(--color-primary);
}

.btn-secondary:hover {
  background: var(--color-primary);
  color: var(--color-white);
}

.btn-ghost {
  background: transparent;
  color: var(--text-primary);
}

.btn-ghost:hover {
  background: var(--bg-tertiary);
}

.btn-lg {
  padding: var(--space-4) var(--space-8);
  font-size: var(--font-size-lg);
  min-height: 56px;
}

.btn-sm {
  padding: var(--space-2) var(--space-4);
  font-size: var(--font-size-sm);
  min-height: 36px;
}

/* ============================================
   6. CARD COMPONENTS
   ============================================ */

.card {
  background: var(--bg-primary);
  border: 2px solid var(--border-color);
  border-radius: var(--radius-2xl);
  padding: var(--space-6);
  transition: all var(--transition-slow);
}

.card:hover {
  border-color: var(--color-primary);
  transform: translateY(-4px);
  box-shadow: var(--shadow-purple-lg);
}

.card-header {
  margin-bottom: var(--space-4);
}

.card-title {
  font-size: var(--font-size-xl);
  font-weight: var(--font-weight-bold);
  color: var(--text-primary);
}

.card-description {
  font-size: var(--font-size-sm);
  color: var(--text-secondary);
  margin-top: var(--space-2);
}

.card-content {
  color: var(--text-secondary);
}

.card-footer {
  margin-top: var(--space-6);
  padding-top: var(--space-4);
  border-top: 1px solid var(--border-color);
}

/* ============================================
   7. FORM COMPONENTS
   ============================================ */

.form-group {
  margin-bottom: var(--space-4);
}

.form-label {
  display: block;
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
  color: var(--text-primary);
  margin-bottom: var(--space-2);
}

.form-input {
  width: 100%;
  padding: var(--space-3) var(--space-4);
  font-family: inherit;
  font-size: var(--font-size-base);
  color: var(--text-primary);
  background: var(--bg-primary);
  border: 2px solid var(--border-color);
  border-radius: var(--radius-lg);
  transition: border-color var(--transition-fast);
}

.form-input:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px var(--color-primary-glow);
}

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

.form-textarea {
  min-height: 120px;
  resize: vertical;
}

.form-select {
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='24' height='24' viewBox='0 0 24 24' fill='none' stroke='%236B7280' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpolyline points='6,9 12,15 18,9'%3E%3C/polyline%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right var(--space-3) center;
  background-size: 20px;
  padding-right: var(--space-10);
}

/* ============================================
   8. BADGE COMPONENTS
   ============================================ */

.badge {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  padding: var(--space-1) var(--space-3);
  font-size: var(--font-size-xs);
  font-weight: var(--font-weight-semibold);
  border-radius: var(--radius-full);
}

.badge-primary {
  background: var(--color-primary-glow);
  color: var(--color-primary);
}

.badge-success {
  background: var(--color-success-light);
  color: var(--color-success);
}

.badge-warning {
  background: var(--color-warning-light);
  color: var(--color-warning);
}

.badge-error {
  background: var(--color-error-light);
  color: var(--color-error);
}

/* ============================================
   9. PROGRESS COMPONENTS
   ============================================ */

.progress {
  height: 8px;
  background: var(--bg-tertiary);
  border-radius: var(--radius-full);
  overflow: hidden;
}

.progress-bar {
  height: 100%;
  background: linear-gradient(90deg, var(--color-primary) 0%, var(--color-primary-light) 100%);
  border-radius: var(--radius-full);
  transition: width var(--transition-slow);
}

.progress-animated .progress-bar {
  position: relative;
}

.progress-animated .progress-bar::after {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.3), transparent);
  animation: shimmer 2s infinite;
}

@keyframes shimmer {
  0% { transform: translateX(-100%); }
  100% { transform: translateX(100%); }
}

/* ============================================
   10. NAVIGATION COMPONENTS
   ============================================ */

.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--nav-height);
  background: var(--bg-primary);
  backdrop-filter: blur(10px);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 var(--space-8);
  z-index: var(--z-nav);
  border-bottom: 1px solid var(--border-color);
}

.nav-logo {
  font-size: var(--font-size-2xl);
  font-weight: var(--font-weight-bold);
  color: var(--color-primary);
  text-decoration: none;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: var(--space-8);
}

.nav-link {
  color: var(--text-secondary);
  text-decoration: none;
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
  transition: color var(--transition-fast);
}

.nav-link:hover,
.nav-link.active {
  color: var(--color-primary);
}

/* ============================================
   11. UTILITY CLASSES
   ============================================ */

/* Flexbox */
.flex { display: flex; }
.flex-col { flex-direction: column; }
.flex-wrap { flex-wrap: wrap; }
.items-center { align-items: center; }
.items-start { align-items: flex-start; }
.items-end { align-items: flex-end; }
.justify-center { justify-content: center; }
.justify-between { justify-content: space-between; }
.justify-end { justify-content: flex-end; }
.gap-2 { gap: var(--space-2); }
.gap-4 { gap: var(--space-4); }
.gap-6 { gap: var(--space-6); }
.gap-8 { gap: var(--space-8); }

/* Grid */
.grid { display: grid; }
.grid-cols-2 { grid-template-columns: repeat(2, 1fr); }
.grid-cols-3 { grid-template-columns: repeat(3, 1fr); }
.grid-cols-4 { grid-template-columns: repeat(4, 1fr); }

/* Spacing */
.m-0 { margin: 0; }
.m-auto { margin: auto; }
.mx-auto { margin-left: auto; margin-right: auto; }
.mt-4 { margin-top: var(--space-4); }
.mt-8 { margin-top: var(--space-8); }
.mb-4 { margin-bottom: var(--space-4); }
.mb-8 { margin-bottom: var(--space-8); }
.p-4 { padding: var(--space-4); }
.p-6 { padding: var(--space-6); }
.p-8 { padding: var(--space-8); }
.px-4 { padding-left: var(--space-4); padding-right: var(--space-4); }
.py-4 { padding-top: var(--space-4); padding-bottom: var(--space-4); }

/* Text alignment */
.text-left { text-align: left; }
.text-center { text-align: center; }
.text-right { text-align: right; }

/* Visibility */
.hidden { display: none; }
.visible { visibility: visible; }
.invisible { visibility: hidden; }
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border-width: 0;
}

/* Container */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--space-6);
}

/* ============================================
   12. ANIMATIONS
   ============================================ */

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

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

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

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

.animate-fade-in { animation: fadeIn 0.3s ease; }
.animate-fade-in-up { animation: fadeInUp 0.5s ease; }
.animate-pulse { animation: pulse 2s infinite; }
.animate-spin { animation: spin 1s linear infinite; }

/* ============================================
   13. RESPONSIVE BREAKPOINTS
   ============================================ */

@media (max-width: 768px) {
  .nav-links {
    display: none;
  }

  .grid-cols-2,
  .grid-cols-3,
  .grid-cols-4 {
    grid-template-columns: 1fr;
  }

  .container {
    padding: 0 var(--space-4);
  }
}

@media (max-width: 480px) {
  :root {
    --space-6: 1.25rem;
    --space-8: 1.5rem;
    --space-12: 2rem;
  }
}

/* ============================================
   14. THEME TOGGLE COMPONENT
   ============================================ */

.theme-toggle {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-2);
  background: var(--bg-tertiary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-full);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.theme-toggle:hover {
  border-color: var(--color-primary);
}

.theme-toggle-icon {
  width: 20px;
  height: 20px;
  transition: transform var(--transition-base);
}

.theme-toggle[data-theme="dark"] .theme-toggle-icon.sun {
  opacity: 0;
  transform: scale(0);
}

.theme-toggle[data-theme="dark"] .theme-toggle-icon.moon {
  opacity: 1;
  transform: scale(1);
}

.theme-toggle[data-theme="light"] .theme-toggle-icon.sun {
  opacity: 1;
  transform: scale(1);
}

.theme-toggle[data-theme="light"] .theme-toggle-icon.moon {
  opacity: 0;
  transform: scale(0);
}

/* ============================================
   15. REDUCED MOTION
   ============================================ */

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