/* Refined Elegant Design System for Metafunctor
 * A timeless, sophisticated design that prioritizes readability,
 * visual harmony, and user experience.
 */

:root {
  /* Typography Scale - Modular Scale (1.250 - Major Third) */
  --font-size-xs: 0.8rem;      /* 12.8px */
  --font-size-sm: 0.875rem;    /* 14px */
  --font-size-base: 1rem;      /* 16px */
  --font-size-md: 1.125rem;    /* 18px */
  --font-size-lg: 1.25rem;     /* 20px */
  --font-size-xl: 1.563rem;    /* 25px */
  --font-size-2xl: 1.953rem;   /* 31.25px */
  --font-size-3xl: 2.441rem;   /* 39px */
  --font-size-4xl: 3.052rem;   /* 48.8px */
  --font-size-5xl: 3.815rem;   /* 61px */

  /* Font Families - Carefully Selected for Readability */
  --font-sans: 'Inter', ui-sans-serif, -apple-system, BlinkMacSystemFont,
               'Segoe UI', Roboto, sans-serif;
  --font-serif: 'Lora', 'Georgia', 'Times New Roman', serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', 'Consolas', monospace;

  /* Font Weights */
  --weight-light: 300;
  --weight-normal: 400;
  --weight-medium: 500;
  --weight-semibold: 600;
  --weight-bold: 700;
  --weight-extrabold: 800;

  /* Line Heights - Optimized for Readability */
  --leading-tight: 1.25;
  --leading-snug: 1.375;
  --leading-normal: 1.5;
  --leading-relaxed: 1.625;
  --leading-loose: 1.75;

  /* Letter Spacing */
  --tracking-tighter: -0.05em;
  --tracking-tight: -0.025em;
  --tracking-normal: 0;
  --tracking-wide: 0.025em;
  --tracking-wider: 0.05em;
  --tracking-widest: 0.1em;

  /* Refined Color Palette - Light Mode */
  --color-text-primary: #1a202c;
  --color-text-secondary: #4a5568;
  --color-text-tertiary: #718096;
  --color-text-inverse: #ffffff;

  --color-bg-primary: #ffffff;
  --color-bg-secondary: #f7fafc;
  --color-bg-tertiary: #edf2f7;
  --color-bg-elevated: #ffffff;

  --color-accent-primary: #2563eb;
  --color-accent-hover: #1d4ed8;
  --color-accent-light: #3b82f6;
  --color-accent-lighter: #dbeafe;

  --color-success: #059669;
  --color-warning: #d97706;
  --color-error: #dc2626;
  --color-info: #0891b2;

  --color-border-subtle: #e2e8f0;
  --color-border-default: #cbd5e0;
  --color-border-strong: #a0aec0;

  /* Shadows - Subtle and Refined */
  --shadow-xs: 0 1px 2px 0 rgb(0 0 0 / 0.05);
  --shadow-sm: 0 1px 3px 0 rgb(0 0 0 / 0.1),
               0 1px 2px -1px rgb(0 0 0 / 0.1);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1),
               0 2px 4px -2px rgb(0 0 0 / 0.1);
  --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1),
               0 4px 6px -4px rgb(0 0 0 / 0.1);
  --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1),
               0 8px 10px -6px rgb(0 0 0 / 0.1);
  --shadow-2xl: 0 25px 50px -12px rgb(0 0 0 / 0.25);
  --shadow-inner: inset 0 2px 4px 0 rgb(0 0 0 / 0.05);

  /* Spacing Scale - Consistent Rhythm */
  --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 */
  --space-32: 8rem;     /* 128px */

  /* Border Radius */
  --radius-none: 0;
  --radius-sm: 0.125rem;
  --radius-default: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  --radius-2xl: 1.5rem;
  --radius-full: 9999px;

  /* Layout */
  --max-width-prose: 65ch;
  --max-width-content: 1280px;
  --max-width-wide: 1536px;

  /* Transitions - Purposeful and Smooth */
  --transition-faster: 100ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-base: 200ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 300ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slower: 500ms cubic-bezier(0.4, 0, 0.2, 1);

  /* Z-index Scale */
  --z-base: 0;
  --z-dropdown: 1000;
  --z-sticky: 1020;
  --z-fixed: 1030;
  --z-modal-backdrop: 1040;
  --z-modal: 1050;
  --z-popover: 1060;
  --z-tooltip: 1070;
}

/* Dark Mode - Carefully Calibrated */
[data-theme="dark"] {
  --color-text-primary: #f7fafc;
  --color-text-secondary: #cbd5e0;
  --color-text-tertiary: #a0aec0;
  --color-text-inverse: #1a202c;

  --color-bg-primary: #0f172a;
  --color-bg-secondary: #1e293b;
  --color-bg-tertiary: #334155;
  --color-bg-elevated: #1e293b;

  --color-accent-primary: #60a5fa;
  --color-accent-hover: #3b82f6;
  --color-accent-light: #93c5fd;
  --color-accent-lighter: #1e3a8a;

  --color-success: #10b981;
  --color-warning: #f59e0b;
  --color-error: #f87171;
  --color-info: #06b6d4;

  --color-border-subtle: #334155;
  --color-border-default: #475569;
  --color-border-strong: #64748b;

  --shadow-sm: 0 1px 3px 0 rgb(0 0 0 / 0.4),
               0 1px 2px -1px rgb(0 0 0 / 0.4);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.4),
               0 2px 4px -2px rgb(0 0 0 / 0.4);
  --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.5),
               0 4px 6px -4px rgb(0 0 0 / 0.5);
  --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.6),
               0 8px 10px -6px rgb(0 0 0 / 0.6);
}

/* ============================================
   BASE STYLES
   ============================================ */

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
  font-feature-settings: "kern" 1, "liga" 1;
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

body {
  font-family: var(--font-sans);
  font-size: var(--font-size-md);
  font-weight: var(--weight-normal);
  line-height: var(--leading-relaxed);
  color: var(--color-text-primary);
  background-color: var(--color-bg-primary);
  transition: color var(--transition-base),
              background-color var(--transition-base);
}

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

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-sans);
  font-weight: var(--weight-bold);
  line-height: var(--leading-tight);
  letter-spacing: var(--tracking-tight);
  color: var(--color-text-primary);
  margin-bottom: var(--space-4);
}

h1 {
  font-size: var(--font-size-4xl);
  font-weight: var(--weight-extrabold);
  letter-spacing: var(--tracking-tighter);
  line-height: 1.1;
}

h2 {
  font-size: var(--font-size-3xl);
  margin-top: var(--space-12);
}

h3 {
  font-size: var(--font-size-2xl);
  margin-top: var(--space-10);
}

h4 {
  font-size: var(--font-size-xl);
  margin-top: var(--space-8);
  font-weight: var(--weight-semibold);
}

h5 {
  font-size: var(--font-size-lg);
  margin-top: var(--space-6);
  font-weight: var(--weight-semibold);
}

h6 {
  font-size: var(--font-size-md);
  margin-top: var(--space-6);
  font-weight: var(--weight-semibold);
  text-transform: uppercase;
  letter-spacing: var(--tracking-wide);
}

p {
  margin-bottom: var(--space-6);
  max-width: var(--max-width-prose);
  color: var(--color-text-secondary);
  line-height: var(--leading-loose);
}

/* Enhanced first paragraph */
.content > p:first-of-type,
article > p:first-of-type {
  font-size: var(--font-size-lg);
  line-height: var(--leading-relaxed);
  color: var(--color-text-primary);
}

/* Subtle drop cap */
.content > p:first-of-type::first-letter,
article > p:first-of-type::first-letter {
  font-size: 3.5em;
  font-weight: var(--weight-bold);
  line-height: 0.85;
  float: left;
  margin: 0.1em 0.15em 0 0;
  color: var(--color-accent-primary);
  font-family: var(--font-serif);
}

/* Links - Refined hover states */
a {
  color: var(--color-accent-primary);
  text-decoration: none;
  transition: color var(--transition-fast);
  position: relative;
}

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

a:focus {
  outline: 2px solid var(--color-accent-primary);
  outline-offset: 2px;
  border-radius: var(--radius-sm);
}

/* Inline links with underline effect */
p a,
li a {
  text-decoration: underline;
  text-decoration-color: var(--color-accent-lighter);
  text-decoration-thickness: 2px;
  text-underline-offset: 2px;
  transition: text-decoration-color var(--transition-fast);
}

p a:hover,
li a:hover {
  text-decoration-color: var(--color-accent-primary);
}

/* Lists */
ul, ol {
  margin-bottom: var(--space-6);
  padding-left: var(--space-6);
}

li {
  margin-bottom: var(--space-3);
  line-height: var(--leading-relaxed);
  color: var(--color-text-secondary);
}

li::marker {
  color: var(--color-accent-primary);
  font-weight: var(--weight-semibold);
}

/* Blockquotes - Elegant styling */
blockquote {
  margin: var(--space-8) 0;
  padding: var(--space-6) var(--space-8);
  border-left: 4px solid var(--color-accent-primary);
  background: var(--color-bg-secondary);
  border-radius: 0 var(--radius-lg) var(--radius-lg) 0;
  font-family: var(--font-serif);
  font-size: var(--font-size-lg);
  font-style: italic;
  color: var(--color-text-secondary);
  position: relative;
}

blockquote::before {
  content: '"';
  font-size: 4rem;
  font-family: var(--font-serif);
  color: var(--color-accent-lighter);
  position: absolute;
  top: -10px;
  left: 10px;
  line-height: 1;
  opacity: 0.3;
}

blockquote p:last-child {
  margin-bottom: 0;
}

/* Code - Beautiful monospace styling */
code {
  font-family: var(--font-mono);
  font-size: 0.9em;
  font-weight: var(--weight-medium);
  background: var(--color-bg-tertiary);
  color: var(--color-accent-primary);
  padding: 0.2em 0.4em;
  border-radius: var(--radius-sm);
  border: 1px solid var(--color-border-subtle);
}

pre {
  margin: var(--space-8) 0;
  padding: var(--space-6);
  background: var(--color-bg-secondary);
  border: 1px solid var(--color-border-subtle);
  border-radius: var(--radius-lg);
  overflow-x: auto;
  box-shadow: var(--shadow-sm);
}

pre code {
  background: none;
  border: none;
  padding: 0;
  font-size: var(--font-size-sm);
  line-height: var(--leading-relaxed);
  color: var(--color-text-primary);
}

/* Tables - Clean and readable */
table {
  width: 100%;
  margin: var(--space-8) 0;
  border-collapse: collapse;
  border: 1px solid var(--color-border-default);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
}

thead {
  background: var(--color-bg-secondary);
}

th {
  padding: var(--space-4) var(--space-6);
  text-align: left;
  font-weight: var(--weight-semibold);
  font-size: var(--font-size-sm);
  text-transform: uppercase;
  letter-spacing: var(--tracking-wide);
  color: var(--color-text-secondary);
  border-bottom: 2px solid var(--color-border-default);
}

td {
  padding: var(--space-4) var(--space-6);
  border-bottom: 1px solid var(--color-border-subtle);
}

tr:last-child td {
  border-bottom: none;
}

tbody tr:hover {
  background: var(--color-bg-secondary);
  transition: background var(--transition-fast);
}

/* Horizontal rule */
hr {
  margin: var(--space-12) 0;
  border: none;
  height: 1px;
  background: linear-gradient(
    to right,
    transparent,
    var(--color-border-default) 50%,
    transparent
  );
}

/* ============================================
   LAYOUT COMPONENTS
   ============================================ */

.container {
  width: 100%;
  max-width: var(--max-width-content);
  margin-left: auto;
  margin-right: auto;
  padding-left: var(--space-6);
  padding-right: var(--space-6);
}

@media (min-width: 640px) {
  .container {
    padding-left: var(--space-8);
    padding-right: var(--space-8);
  }
}

@media (min-width: 1024px) {
  .container {
    padding-left: var(--space-12);
    padding-right: var(--space-12);
  }
}

/* Section spacing */
section {
  padding: var(--space-16) 0;
}

@media (min-width: 768px) {
  section {
    padding: var(--space-24) 0;
  }
}

/* ============================================
   HEADER & NAVIGATION
   ============================================ */

.elegant-header {
  position: sticky;
  top: 0;
  z-index: var(--z-sticky);
  background: rgba(255, 255, 255, 0.8);
  backdrop-filter: blur(12px) saturate(180%);
  -webkit-backdrop-filter: blur(12px) saturate(180%);
  border-bottom: 1px solid var(--color-border-subtle);
  transition: all var(--transition-base);
}

[data-theme="dark"] .elegant-header {
  background: rgba(15, 23, 42, 0.8);
}

.elegant-header.scrolled {
  box-shadow: var(--shadow-md);
}

.header-inner {
  max-width: var(--max-width-content);
  margin: 0 auto;
  padding: var(--space-4) var(--space-8);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.site-logo {
  font-size: var(--font-size-xl);
  font-weight: var(--weight-extrabold);
  letter-spacing: var(--tracking-tighter);
  color: var(--color-text-primary);
  transition: color var(--transition-fast);
}

.site-logo:hover {
  color: var(--color-accent-primary);
}

.nav-primary ul {
  display: flex;
  gap: var(--space-2);
  list-style: none;
  align-items: center;
}

.nav-primary a {
  display: block;
  padding: var(--space-2) var(--space-4);
  font-size: var(--font-size-sm);
  font-weight: var(--weight-medium);
  color: var(--color-text-secondary);
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
  position: relative;
}

.nav-primary a::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: var(--space-4);
  right: var(--space-4);
  height: 2px;
  background: var(--color-accent-primary);
  transform: scaleX(0);
  transition: transform var(--transition-base);
}

.nav-primary a:hover,
.nav-primary a.active {
  color: var(--color-text-primary);
  background: var(--color-bg-secondary);
}

.nav-primary a:hover::after,
.nav-primary a.active::after {
  transform: scaleX(1);
}

/* ============================================
   HERO SECTION
   ============================================ */

.hero-elegant {
  padding: var(--space-24) var(--space-8);
  text-align: center;
  background: linear-gradient(
    180deg,
    var(--color-bg-primary) 0%,
    var(--color-bg-secondary) 100%
  );
}

.hero-title {
  margin-bottom: var(--space-6);
  background: linear-gradient(
    135deg,
    var(--color-text-primary) 0%,
    var(--color-accent-primary) 100%
  );
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-subtitle {
  font-size: var(--font-size-xl);
  color: var(--color-text-secondary);
  max-width: 600px;
  margin: 0 auto var(--space-12);
  line-height: var(--leading-relaxed);
}

.hero-stats {
  display: flex;
  justify-content: center;
  gap: var(--space-12);
  flex-wrap: wrap;
  margin-top: var(--space-12);
}

.stat-item {
  text-align: center;
}

.stat-number {
  display: block;
  font-size: var(--font-size-4xl);
  font-weight: var(--weight-extrabold);
  color: var(--color-accent-primary);
  line-height: 1;
  margin-bottom: var(--space-2);
}

.stat-label {
  font-size: var(--font-size-sm);
  color: var(--color-text-tertiary);
  text-transform: uppercase;
  letter-spacing: var(--tracking-wider);
  font-weight: var(--weight-medium);
}

/* ============================================
   CARDS & CONTENT BLOCKS
   ============================================ */

.card {
  background: var(--color-bg-elevated);
  border: 1px solid var(--color-border-subtle);
  border-radius: var(--radius-xl);
  padding: var(--space-8);
  transition: all var(--transition-base);
  box-shadow: var(--shadow-sm);
}

.card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
  border-color: var(--color-accent-light);
}

.artifact-card,
.content-card,
.project-card {
  background: var(--color-bg-elevated);
  border: 1px solid var(--color-border-subtle);
  border-radius: var(--radius-lg);
  overflow: hidden;
  transition: all var(--transition-base);
  display: flex;
  flex-direction: column;
  box-shadow: var(--shadow-xs);
}

.artifact-card:hover,
.content-card:hover,
.project-card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-xl);
  border-color: var(--color-accent-primary);
}

.artifact-header,
.card-header {
  padding: var(--space-6);
  background: var(--color-bg-secondary);
  border-bottom: 1px solid var(--color-border-subtle);
}

.artifact-title,
.card-title {
  font-size: var(--font-size-xl);
  margin: var(--space-2) 0;
  line-height: var(--leading-snug);
}

.artifact-body,
.card-body {
  padding: var(--space-6);
  flex: 1;
}

.artifact-description,
.card-description {
  color: var(--color-text-secondary);
  line-height: var(--leading-relaxed);
  margin-bottom: var(--space-4);
}

/* Badge styles */
.artifact-type,
.status-badge,
.type-badge {
  display: inline-block;
  padding: var(--space-1) var(--space-3);
  background: var(--color-accent-primary);
  color: var(--color-text-inverse);
  border-radius: var(--radius-full);
  font-size: var(--font-size-xs);
  font-weight: var(--weight-semibold);
  text-transform: uppercase;
  letter-spacing: var(--tracking-wide);
}

/* ============================================
   FOOTER
   ============================================ */

.elegant-footer {
  background: var(--color-text-primary);
  color: var(--color-text-inverse);
  padding: var(--space-16) var(--space-8) var(--space-8);
  margin-top: var(--space-24);
}

.footer-content {
  max-width: var(--max-width-content);
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: var(--space-12);
  margin-bottom: var(--space-12);
}

.footer-section h4 {
  color: var(--color-text-inverse);
  font-size: var(--font-size-sm);
  text-transform: uppercase;
  letter-spacing: var(--tracking-wider);
  margin-bottom: var(--space-4);
  font-weight: var(--weight-semibold);
}

.footer-links {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

.footer-links a {
  color: rgba(255, 255, 255, 0.7);
  transition: color var(--transition-fast);
}

.footer-links a:hover {
  color: rgba(255, 255, 255, 1);
}

.footer-bottom {
  max-width: var(--max-width-content);
  margin: 0 auto;
  padding-top: var(--space-8);
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--space-4);
  font-size: var(--font-size-sm);
  color: rgba(255, 255, 255, 0.6);
}

/* ============================================
   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-width: 0;
}

.skip-to-main {
  position: absolute;
  top: -100px;
  left: 0;
  background: var(--color-accent-primary);
  color: var(--color-text-inverse);
  padding: var(--space-3) var(--space-6);
  text-decoration: none;
  font-weight: var(--weight-semibold);
  z-index: var(--z-tooltip);
  border-radius: 0 0 var(--radius-md) 0;
  transition: top var(--transition-fast);
}

.skip-to-main:focus {
  top: 0;
}

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

@media (max-width: 768px) {
  :root {
    --font-size-4xl: 2.441rem;
    --font-size-3xl: 1.953rem;
  }

  .hero-elegant {
    padding: var(--space-16) var(--space-6);
  }

  .hero-stats {
    flex-direction: column;
    gap: var(--space-8);
  }

  .footer-content {
    grid-template-columns: 1fr;
    text-align: center;
  }

  .footer-bottom {
    flex-direction: column;
    text-align: center;
  }
}

/* ============================================
   PERFORMANCE OPTIMIZATIONS
   ============================================ */

/* GPU acceleration for transforms */
.card:hover,
.artifact-card:hover {
  will-change: transform;
}

/* Prevent layout shift */
img,
video {
  max-width: 100%;
  height: auto;
  display: block;
}

/* Loading state */
.loading {
  opacity: 0.6;
  pointer-events: none;
}

/* Focus visible for better keyboard navigation */
:focus-visible {
  outline: 2px solid var(--color-accent-primary);
  outline-offset: 2px;
}