/* rlm.md — Design System
   Dark editorial. Warm accents on cold dark. Geometric not generic. */

@import url('https://fonts.googleapis.com/css2?family=Space+Grotesk:wght@400;500;600;700&family=DM+Sans:ital,wght@0,400;0,500;0,700;1,400&family=JetBrains+Mono:wght@400;500&display=swap');

:root {
  --bg: #08080c;
  --bg-raised: #101018;
  --bg-subtle: #16161f;
  --text: #e0dcd4;
  --text-muted: #8a8698;
  --text-dim: #5a5668;
  --accent: #c9a84c;
  --accent-dim: rgba(201,168,76,0.15);
  --teal: #4a9ead;
  --teal-dim: rgba(74,158,173,0.12);
  --rose: #b05a6a;
  --font-display: 'Space Grotesk', system-ui, sans-serif;
  --font-body: 'DM Sans', system-ui, sans-serif;
  --font-mono: 'JetBrains Mono', monospace;
  --max-w: 72rem;
  --gutter: clamp(1.5rem, 5vw, 4rem);
}

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
}

body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-body);
  line-height: 1.7;
  min-height: 100vh;
  overflow-x: hidden;
}

::selection {
  background: var(--accent);
  color: var(--bg);
}

/* --- Noise overlay --- */
body::before {
  content: '';
  position: fixed;
  inset: 0;
  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)' opacity='0.03'/%3E%3C/svg%3E");
  pointer-events: none;
  z-index: 9999;
}

/* --- Typography --- */
h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: 600;
  line-height: 1.15;
  letter-spacing: -0.02em;
  color: var(--text);
}

h1 { font-size: clamp(2.4rem, 5vw, 4rem); }
h2 { font-size: clamp(1.6rem, 3vw, 2.4rem); margin-bottom: 1rem; }
h3 { font-size: clamp(1.1rem, 2vw, 1.5rem); margin-bottom: 0.75rem; }

p { max-width: 65ch; margin-bottom: 1.2em; }
p:last-child { margin-bottom: 0; }

a {
  color: var(--accent);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: border-color 0.2s;
}
a:hover { border-bottom-color: var(--accent); }

strong { color: var(--text); font-weight: 600; }
em { color: var(--text-muted); }

/* --- Navigation --- */
.site-nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  padding: 1.25rem var(--gutter);
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: #08080c;
  border-bottom: 1px solid rgba(255,255,255,0.06);
}

.site-logo {
  font-family: var(--font-mono);
  font-size: 1.1rem;
  font-weight: 500;
  color: var(--text);
  border: none;
  letter-spacing: -0.03em;
}
.site-logo .dot { color: var(--accent); }
.site-logo:hover { border: none; }

.nav-links {
  display: flex;
  gap: 0.25rem;
  list-style: none;
}

.nav-links a {
  font-family: var(--font-display);
  font-size: 0.82rem;
  font-weight: 500;
  color: var(--text-muted);
  padding: 0.4rem 0.85rem;
  border-radius: 4px;
  border: none;
  transition: color 0.2s, background 0.2s;
  letter-spacing: 0.01em;
}
.nav-links a:hover { color: var(--text); background: var(--bg-raised); }
.nav-links a.active { color: var(--accent); background: var(--accent-dim); }

.nav-toggle {
  display: none;
  background: none;
  border: 1px solid var(--text-dim);
  color: var(--text);
  font-size: 1.2rem;
  padding: 0.3rem 0.6rem;
  border-radius: 4px;
  cursor: pointer;
  font-family: var(--font-mono);
}

/* --- Layout --- */
.page-body {
  padding-top: 5rem;
  padding-bottom: 6rem;
}

.container {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 var(--gutter);
}

.section {
  margin-bottom: 5rem;
}

/* --- Hero (index) --- */
.hero {
  padding: 8rem 0 5rem;
  position: relative;
}

.hero-label {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--accent);
  letter-spacing: 0.15em;
  text-transform: uppercase;
  margin-bottom: 1.5rem;
  display: block;
}

.hero h1 {
  font-size: clamp(2.8rem, 6vw, 5rem);
  font-weight: 700;
  margin-bottom: 1.5rem;
  max-width: 18ch;
}

.hero h1 .accent { color: var(--accent); }

.hero-sub {
  font-size: clamp(1.05rem, 1.8vw, 1.25rem);
  color: var(--text-muted);
  max-width: 52ch;
  line-height: 1.75;
  margin-bottom: 2.5rem;
}

/* Geometric accent — diagonal line */
.hero::after {
  content: '';
  position: absolute;
  top: 6rem;
  right: var(--gutter);
  width: 30vw;
  max-width: 20rem;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--accent) 40%, var(--teal));
  transform: rotate(-35deg);
  transform-origin: right center;
  opacity: 0.4;
}

/* --- Cards --- */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(min(20rem, 100%), 1fr));
  gap: 1.5rem;
  max-width: 100%;
}

.card {
  background: var(--bg-raised);
  border: 1px solid rgba(255,255,255,0.05);
  border-radius: 8px;
  padding: 2rem;
  transition: border-color 0.3s, transform 0.2s;
  position: relative;
}
.card:hover {
  border-color: rgba(201,168,76,0.2);
  transform: translateY(-2px);
}

.card-number {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--text-dim);
  letter-spacing: 0.1em;
  margin-bottom: 1rem;
}

.card h3 { color: var(--text); }
.card p { color: var(--text-muted); font-size: 0.92rem; }

/* --- LLM vs RLM architecture comparison --- */
.arch-compare {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.5rem;
}

.arch-col {
  background: var(--bg-raised);
  border: 1px solid rgba(255,255,255,0.05);
  border-radius: 8px;
  padding: 1.5rem;
  text-align: center;
}

.arch-col--accent {
  border-color: rgba(201,168,76,0.2);
}

.arch-label {
  font-family: var(--font-display);
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 1rem;
}

.arch-diagram {
  display: flex;
  justify-content: center;
}

.arch-svg {
  width: 100%;
  max-width: 280px;
  height: auto;
}

@media (max-width: 768px) {
  .arch-compare { grid-template-columns: 1fr; gap: 1rem; }
  .arch-col { padding: 1.25rem 0.75rem; }
  .arch-label { font-size: 0.88rem; }
  .arch-svg { max-width: 100%; width: 100%; }
}

/* --- Asymmetric two-col --- */
.split {
  display: grid;
  grid-template-columns: 1fr 1.4fr;
  max-width: 100%;
  gap: 4rem;
  align-items: start;
}

.split-label {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--accent);
  letter-spacing: 0.15em;
  text-transform: uppercase;
  margin-bottom: 0.5rem;
}

/* --- Code blocks --- */
pre {
  background: #0c0c14;
  border: 1px solid rgba(255,255,255,0.06);
  border-radius: 6px;
  padding: 1.5rem;
  overflow-x: auto;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  line-height: 1.65;
  margin: 1.5rem 0;
  position: relative;
  max-width: 100%;
  word-wrap: break-word;
  white-space: pre-wrap;
}

pre .comment { color: #5a5668; }
pre .keyword { color: var(--teal); }
pre .string { color: var(--accent); }
pre .function { color: #b4a0e5; }
pre .number { color: var(--rose); }
pre .type { color: #7ec4a0; }

code {
  font-family: var(--font-mono);
  font-size: 0.88em;
  background: var(--bg-raised);
  padding: 0.15em 0.4em;
  border-radius: 3px;
  color: var(--teal);
}
pre code {
  background: none;
  padding: 0;
  color: var(--text);
}

/* --- Blockquote --- */
blockquote {
  border-left: 2px solid var(--accent);
  padding: 1rem 0 1rem 1.5rem;
  margin: 2rem 0;
  color: var(--text-muted);
  font-style: italic;
}

/* --- Divider --- */
.divider {
  border: none;
  height: 1px;
  background: linear-gradient(90deg, var(--accent) 0%, transparent 60%);
  margin: 4rem 0;
  opacity: 0.3;
}

/* --- Tag --- */
.tag {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--teal);
  background: var(--teal-dim);
  padding: 0.25rem 0.65rem;
  border-radius: 3px;
  letter-spacing: 0.04em;
  margin-right: 0.4rem;
  margin-bottom: 0.4rem;
}

/* --- Table --- */
table {
  width: 100%;
  border-collapse: collapse;
  margin: 2rem 0;
  font-size: 0.9rem;
}
th, td {
  text-align: left;
  padding: 0.75rem 1rem;
  border-bottom: 1px solid rgba(255,255,255,0.06);
}
th {
  font-family: var(--font-display);
  font-weight: 600;
  color: var(--text);
  font-size: 0.8rem;
  letter-spacing: 0.05em;
  text-transform: uppercase;
}
td { color: var(--text-muted); }
tr:hover td { color: var(--text); }

/* --- Footer --- */
.site-footer {
  border-top: 1px solid rgba(255,255,255,0.04);
  padding: 3rem var(--gutter);
  text-align: center;
  font-size: 0.8rem;
  color: var(--text-dim);
}

/* --- Page header (inner pages) --- */
.page-header {
  padding: 5rem 0 3rem;
  border-bottom: 1px solid rgba(255,255,255,0.04);
  margin-bottom: 4rem;
}

.page-header h1 {
  font-size: clamp(2rem, 4vw, 3.2rem);
  margin-bottom: 1rem;
}

.page-header .lead {
  font-size: 1.1rem;
  color: var(--text-muted);
  max-width: 55ch;
}

/* --- Aside/callout --- */
.callout {
  background: var(--accent-dim);
  border-left: 3px solid var(--accent);
  padding: 1.5rem;
  border-radius: 0 6px 6px 0;
  margin: 2rem 0;
}
.callout p { color: var(--text); margin: 0; }

.callout-teal {
  background: var(--teal-dim);
  border-left-color: var(--teal);
}

/* --- Timeline --- */
.timeline-item {
  display: grid;
  grid-template-columns: 6rem 1fr;
  gap: 2rem;
  padding: 2rem 0;
  border-bottom: 1px solid rgba(255,255,255,0.04);
}

.timeline-year {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--accent);
  padding-top: 0.3rem;
}

/* --- Geometric decorations --- */
.geo-corner {
  position: absolute;
  width: 120px;
  height: 120px;
  border: 1px solid rgba(201,168,76,0.1);
  pointer-events: none;
}
.geo-corner--tr { top: -1px; right: -1px; border-left: none; border-bottom: none; }
.geo-corner--bl { bottom: -1px; left: -1px; border-right: none; border-top: none; }

/* --- Animations --- */
.fade-in {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}
.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}

/* Staggered children */
.stagger > * { transition-delay: calc(var(--i, 0) * 80ms); }

/* --- Responsive --- */
@media (max-width: 768px) {
  .split {
    grid-template-columns: 1fr;
    gap: 2rem;
  }
  .card-grid {
    grid-template-columns: 1fr;
  }
  .hero::after { display: none; }
  .nav-links {
    display: none;
    position: fixed;
    inset: 0;
    background: rgba(8,8,12,0.97);
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 1rem;
    z-index: 999;
  }
  .nav-links.open { display: flex; }
  .nav-links a { font-size: 1.1rem; padding: 0.8rem 1.5rem; }
  .nav-toggle { display: block; }
  .timeline-item {
    grid-template-columns: 1fr;
    gap: 0.5rem;
  }
  .hero { padding: 5rem 0 3rem; }
  .page-header { padding: 3rem 0 2rem; margin-bottom: 3rem; }
}

@media (max-width: 480px) {
  h1 { font-size: 1.8rem; }
  h2 { font-size: 1.3rem; }
  pre { font-size: 0.78rem; padding: 1rem; }
}