/* -------------------------------------------
   CUSTOM PROPERTIES - CONCEPT 2 BLUE PALETTE
   ------------------------------------------- */
:root {
  --c-bg: #FBFCFE;
  --c-bg-elevated: #FFFFFF;
  --c-bg-glass: rgba(251, 252, 254, 0.75);
  --c-surface: #F2F5F9;
  --c-border: rgba(24, 95, 165, 0.10);
  --c-border-hover: rgba(24, 95, 165, 0.22);
  --c-text: #0A1628;
  --c-text-muted: #6B7D92;
  --c-text-dim: #9BAFC4;
  --c-accent: #185FA5;
  --c-accent-light: #378ADD;
  --c-accent-dim: #185FA5;
  --c-accent-glow: rgba(24, 95, 165, 0.06);
  --c-accent-pale: #E6F1FB;
  --c-deep: #0C447C;
  --c-white: #FFFFFF;

  --font-display: 'Instrument Serif', Georgia, serif;
  --font-body: 'Plus Jakarta Sans', system-ui, sans-serif;
  --font-mono: 'Geist Mono', 'SF Mono', monospace;

  --ease-out-expo: cubic-bezier(0.16, 1, 0.3, 1);

  --space-xs: clamp(0.25rem, 0.5vw, 0.5rem);
  --space-sm: clamp(0.5rem, 1vw, 1rem);
  --space-md: clamp(1rem, 2vw, 2rem);
  --space-lg: clamp(2rem, 4vw, 4rem);
  --space-xl: clamp(3rem, 6vw, 6rem);
  --space-2xl: clamp(4rem, 10vw, 10rem);
}

/* -------------------------------------------
   RESET & BASE
   ------------------------------------------- */
*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; scrollbar-color: var(--c-accent) var(--c-surface); }
body {
  font-family: var(--font-body);
  background: var(--c-bg);
  color: var(--c-text);
  line-height: 1.6;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}
a { color: inherit; text-decoration: none; }
button { font: inherit; cursor: pointer; border: none; background: none; color: inherit; }

/* Grain overlay */
body::before {
  content: '';
  position: fixed;
  inset: 0;
  z-index: 9999;
  pointer-events: none;
  opacity: 0.018;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
  background-repeat: repeat;
  background-size: 200px;
}

/* -------------------------------------------
   ANIMATIONS
   ------------------------------------------- */
@keyframes fade-up {
  from { opacity: 0; transform: translateY(30px); }
  to { opacity: 1; transform: translateY(0); }
}
.animate-in { animation: fade-up 0.8s var(--ease-out-expo) both; }
.animate-delay-1 { animation-delay: 0.1s; }
.animate-delay-2 { animation-delay: 0.2s; }

/* -------------------------------------------
   LAYOUT
   ------------------------------------------- */
.container {
  width: min(90%, 1200px);
  margin-inline: auto;
}

/* -------------------------------------------
   NAVIGATION
   ------------------------------------------- */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  padding: var(--space-sm) 0;
  background: var(--c-bg-glass);
  backdrop-filter: blur(20px) saturate(1.4);
  -webkit-backdrop-filter: blur(20px) saturate(1.4);
  border-bottom: 1px solid var(--c-border);
}
.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-xs) 0;
}
.nav-logo {
  display: flex;
  align-items: center;
  gap: 12px;
}
.nav-logo svg, .logo-mark { width: 36px; height: 36px; flex-shrink: 0; }
.nav-wordmark {
  font-family: var(--font-body);
  font-weight: 600;
  font-size: 1.1rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}
.nav-links {
  display: flex;
  align-items: center;
  gap: clamp(1.5rem, 3vw, 3rem);
  list-style: none;
}
.nav-links a {
  font-size: 0.82rem;
  font-weight: 400;
  letter-spacing: 0.06em;
  color: var(--c-text-muted);
  transition: color 0.3s;
  text-transform: uppercase;
}
.nav-links a:hover { color: var(--c-accent); }
.nav-cta {
  font-size: 0.82rem !important;
  font-weight: 500 !important;
  letter-spacing: 0.06em;
  color: var(--c-white) !important;
  background: var(--c-accent);
  padding: 0.55em 1.4em;
  border-radius: 6px;
  transition: background 0.3s, transform 0.3s;
}
.nav-cta:hover {
  background: var(--c-accent-light) !important;
  color: var(--c-white) !important;
  transform: translateY(-1px);
}
.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  padding: 4px;
}
.nav-toggle span {
  display: block;
  width: 22px;
  height: 1.5px;
  background: var(--c-text);
  transition: transform 0.3s, opacity 0.3s;
}
@media (max-width: 768px) {
  .nav-toggle { display: flex; }
  .nav-links {
    position: fixed;
    inset: 0;
    flex-direction: column;
    justify-content: center;
    background: var(--c-bg);
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.4s;
  }
  .nav-links.open { opacity: 1; pointer-events: all; }
  .nav-links a { font-size: 1.2rem; }
}

/* -------------------------------------------
   PAGE HEADER
   ------------------------------------------- */
.page-header {
  padding-top: calc(80px + var(--space-2xl));
  padding-bottom: var(--space-xl);
  position: relative;
  border-bottom: 1px solid var(--c-border);
}
.page-header::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 100%;
  background: radial-gradient(ellipse 60% 80% at 50% 0%, rgba(24, 95, 165, 0.04), transparent);
  pointer-events: none;
}
.page-header-content { position: relative; }
.page-breadcrumb {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  font-weight: 400;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--c-text-dim);
  margin-bottom: var(--space-sm);
}
.page-breadcrumb a {
  color: var(--c-accent);
  transition: color 0.3s;
}
.page-breadcrumb a:hover { color: var(--c-accent); }
.page-breadcrumb span { margin-inline: 0.5em; color: var(--c-text-dim); }

.page-header h1 {
  font-family: var(--font-display);
  font-size: clamp(2.2rem, 5vw, 4rem);
  font-weight: 400;
  line-height: 1.05;
}
.page-header h1 em { font-style: italic; color: var(--c-accent); }
.page-meta {
  margin-top: var(--space-sm);
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--c-text-dim);
  letter-spacing: 0.06em;
}

/* -------------------------------------------
   PAGE CONTENT - PROSE
   ------------------------------------------- */
.page-body { padding-block: var(--space-xl); }
.page-content { max-width: 720px; }

.prose h2 {
  font-family: var(--font-display);
  font-size: clamp(1.5rem, 3vw, 2rem);
  font-weight: 400;
  margin-top: var(--space-lg);
  margin-bottom: var(--space-sm);
  color: var(--c-text);
}
.prose h3 {
  font-family: var(--font-body);
  font-size: 1.1rem;
  font-weight: 600;
  margin-top: var(--space-md);
  margin-bottom: var(--space-xs);
  color: var(--c-text);
}
.prose p {
  font-size: 0.95rem;
  color: var(--c-text-muted);
  line-height: 1.8;
  margin-bottom: 1.2rem;
}
.prose a {
  color: var(--c-accent);
  text-decoration: underline;
  text-decoration-color: var(--c-accent-dim);
  text-underline-offset: 3px;
  transition: text-decoration-color 0.3s;
}
.prose a:hover { text-decoration-color: var(--c-accent); }
.prose ul, .prose ol {
  padding-left: 1.2rem;
  margin-bottom: 1.2rem;
}
.prose li {
  font-size: 0.95rem;
  color: var(--c-text-muted);
  line-height: 1.8;
  margin-bottom: 0.4rem;
}
.prose li::marker { color: var(--c-accent-dim); }
.prose blockquote {
  border-left: 2px solid var(--c-accent-dim);
  padding-left: var(--space-md);
  margin-block: var(--space-md);
  font-style: italic;
  color: var(--c-text-dim);
}
.prose code {
  font-family: var(--font-mono);
  font-size: 0.85em;
  background: var(--c-surface);
  border: 1px solid var(--c-border);
  padding: 0.15em 0.4em;
  border-radius: 4px;
  color: var(--c-accent);
}
.prose pre {
  background: var(--c-surface);
  border: 1px solid var(--c-border);
  border-radius: 10px;
  padding: 1.5rem;
  overflow-x: auto;
  margin-block: var(--space-md);
  font-family: var(--font-mono);
  font-size: 0.82rem;
  line-height: 1.7;
  color: var(--c-text-muted);
}
.prose pre code { background: none; border: none; padding: 0; }
.prose hr {
  border: none;
  height: 1px;
  background: var(--c-border);
  margin-block: var(--space-lg);
}
.prose table {
  width: 100%;
  border-collapse: collapse;
  margin-block: var(--space-md);
  font-size: 0.88rem;
}
.prose th {
  text-align: left;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  font-weight: 500;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--c-text-muted);
  padding: 0.8rem 1rem;
  border-bottom: 1px solid var(--c-border);
}
.prose td {
  padding: 0.8rem 1rem;
  border-bottom: 1px solid var(--c-border);
  color: var(--c-text-muted);
}
.prose tr:last-child td { border-bottom: none; }

/* -------------------------------------------
   SIDEBAR LAYOUT
   ------------------------------------------- */
.page-layout-sidebar {
  display: grid;
  grid-template-columns: 1fr 240px;
  gap: var(--space-xl);
}
@media (max-width: 900px) {
  .page-layout-sidebar { grid-template-columns: 1fr; }
  .page-sidebar { display: none; }
}
.page-sidebar {
  position: sticky;
  top: 100px;
  align-self: start;
}
.toc-title {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  font-weight: 500;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--c-text-muted);
  margin-bottom: 1rem;
}
.toc-list { list-style: none; }
.toc-list li { margin-bottom: 0.5rem; }
.toc-list a {
  font-size: 0.82rem;
  color: var(--c-text-dim);
  transition: color 0.3s;
  display: block;
  padding: 0.2em 0;
  border-left: 1px solid transparent;
  padding-left: 1rem;
}
.toc-list a:hover,
.toc-list a.active {
  color: var(--c-accent);
  border-left-color: var(--c-accent);
}

/* -------------------------------------------
   FOOTER
   ------------------------------------------- */
.footer {
  border-top: 1px solid var(--c-border);
  background: var(--c-surface);
  padding-block: var(--space-xl) var(--space-lg);
}
.footer-grid {
  display: grid;
  grid-template-columns: 2fr repeat(3, 1fr);
  gap: var(--space-lg);
}
@media (max-width: 768px) {
  .footer-grid { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 480px) {
  .footer-grid { grid-template-columns: 1fr; }
}
.footer-brand p {
  color: var(--c-text-dim);
  font-size: 0.82rem;
  line-height: 1.7;
  margin-top: 1rem;
  max-width: 280px;
}
.footer-col h4 {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  font-weight: 500;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--c-text-muted);
  margin-bottom: 1rem;
}
.footer-col ul { list-style: none; }
.footer-col li { margin-bottom: 0.6rem; }
.footer-col a {
  font-size: 0.85rem;
  color: var(--c-text-dim);
  transition: color 0.3s;
}
.footer-col a:hover { color: var(--c-accent); }
.footer-bottom {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-top: var(--space-xl);
  padding-top: var(--space-md);
  border-top: 1px solid var(--c-border);
  font-size: 0.75rem;
  color: var(--c-text-dim);
  flex-wrap: wrap;
  gap: 1rem;
}
.footer-bottom-links {
  display: flex;
  gap: 1.5rem;
  list-style: none;
}
.footer-bottom-links a {
  color: var(--c-text-dim);
  transition: color 0.3s;
}
.footer-bottom-links a:hover { color: var(--c-text-muted); }