/* ─── Tokens ────────────────────────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
html { scroll-behavior: smooth; }

:root {
  --bg:         #fbfbf9;
  --bg-alt:     #f3f3ef;
  --surface:    #ffffff;
  --surface-2:  #f6f6f2;
  --text:       #0f172a;
  --text-soft:  #3f4a5c;
  --text-mute:  #6b7385;
  --border:     #e4e5df;
  --border-strong: #cfd1c8;
  --accent:     #b45309;
  --accent-bg:  #fff4e0;
  --amber:      #f59e0b;
  --ai:         #b45309;
  --de:         #0f766e;
  --ml:         #4338ca;
  --live:       #15803d;
  --live-bg:    #dcfce7;
  --link:       #1d4ed8;
  --shadow:     0 1px 2px rgba(15,23,42,.05), 0 6px 20px rgba(15,23,42,.05);
  --shadow-lg:  0 4px 12px rgba(15,23,42,.08), 0 20px 48px rgba(15,23,42,.10);
  --nav-bg:     rgba(251,251,249,.85);
  --grid-line:  rgba(15,23,42,.06);

  --radius:     10px;
  --radius-lg:  16px;
  --max-w:      1080px;
  --prose-w:    680px;
  --font:       "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --mono:       "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg:         #0a1628;
    --bg-alt:     #0d1b30;
    --surface:    #10203a;
    --surface-2:  #14263f;
    --text:       #f4f6fa;
    --text-soft:  #c3cbd8;
    --text-mute:  #8b96a8;
    --border:     rgba(255,255,255,.09);
    --border-strong: rgba(255,255,255,.18);
    --accent:     #fbbf24;
    --accent-bg:  rgba(251,191,36,.10);
    --ai:         #fbbf24;
    --de:         #2dd4bf;
    --ml:         #a5b4fc;
    --live:       #4ade80;
    --live-bg:    rgba(74,222,128,.14);
    --link:       #7cb0ff;
    --shadow:     0 1px 2px rgba(0,0,0,.4), 0 6px 20px rgba(0,0,0,.35);
    --shadow-lg:  0 4px 12px rgba(0,0,0,.45), 0 20px 48px rgba(0,0,0,.5);
    --nav-bg:     rgba(10,22,40,.85);
    --grid-line:  rgba(255,255,255,.05);
  }
}
:root[data-theme="dark"] {
  --bg:         #0a1628;
  --bg-alt:     #0d1b30;
  --surface:    #10203a;
  --surface-2:  #14263f;
  --text:       #f4f6fa;
  --text-soft:  #c3cbd8;
  --text-mute:  #8b96a8;
  --border:     rgba(255,255,255,.09);
  --border-strong: rgba(255,255,255,.18);
  --accent:     #fbbf24;
  --accent-bg:  rgba(251,191,36,.10);
  --ai:         #fbbf24;
  --de:         #2dd4bf;
  --ml:         #a5b4fc;
  --live:       #4ade80;
  --live-bg:    rgba(74,222,128,.14);
  --link:       #7cb0ff;
  --shadow:     0 1px 2px rgba(0,0,0,.4), 0 6px 20px rgba(0,0,0,.35);
  --shadow-lg:  0 4px 12px rgba(0,0,0,.45), 0 20px 48px rgba(0,0,0,.5);
  --nav-bg:     rgba(10,22,40,.85);
  --grid-line:  rgba(255,255,255,.05);
}

/* ─── Base ──────────────────────────────────────────────────────────────── */
body {
  font-family: var(--font);
  font-size: 16px;
  line-height: 1.65;
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}
a { color: var(--link); text-decoration: none; transition: color .15s; }
a:hover { color: var(--accent); }
a:focus-visible, button:focus-visible { outline: 2px solid var(--amber); outline-offset: 3px; border-radius: 4px; }
h1, h2, h3, h4 { margin: 0; font-weight: 700; letter-spacing: -0.015em; line-height: 1.2; }
p { margin: 0; }
ul { margin: 0; padding: 0; list-style: none; }
dl, dd, dt { margin: 0; }

.skip {
  position: absolute; left: -999px; top: 8px; z-index: 200;
  background: var(--text); color: var(--bg); padding: .5rem .9rem; border-radius: 6px;
}
.skip:focus { left: 8px; }

.eyebrow {
  font-family: var(--mono);
  font-size: .76rem; font-weight: 600;
  letter-spacing: .14em; text-transform: uppercase;
  color: var(--accent);
  margin: 0 0 .9rem;
}

/* ─── Nav ───────────────────────────────────────────────────────────────── */
.nav {
  position: sticky; top: 0; z-index: 100;
  background: var(--nav-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}
.nav-inner {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 1.5rem;
  height: 60px;
  display: flex; align-items: center; justify-content: space-between; gap: 1rem;
}
.brand { display: inline-flex; align-items: center; color: var(--text); }
.brand-mark {
  font-family: var(--mono); font-weight: 600; font-size: .9rem; letter-spacing: .08em;
  padding: .3rem .55rem; border: 1.5px solid var(--text); border-radius: 6px;
}
.brand:hover .brand-mark { border-color: var(--accent); color: var(--accent); }
.nav-links { display: flex; gap: 1.6rem; }
.nav-links a { font-size: .92rem; font-weight: 500; color: var(--text-soft); }
.nav-links a:hover { color: var(--text); }
.nav-actions { display: flex; align-items: center; gap: .4rem; }
.nav-gh, .theme-toggle {
  display: inline-flex; align-items: center; justify-content: center;
  width: 36px; height: 36px; border-radius: 8px;
  color: var(--text-soft); background: transparent; border: 1px solid transparent; cursor: pointer;
  transition: background .15s, color .15s, border-color .15s;
}
.nav-gh:hover, .theme-toggle:hover { background: var(--surface-2); color: var(--text); border-color: var(--border); }
.theme-toggle .icon-moon { display: none; }
:root[data-theme="dark"] .theme-toggle .icon-sun { display: none; }
:root[data-theme="dark"] .theme-toggle .icon-moon { display: inline; }
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) .theme-toggle .icon-sun { display: none; }
  :root:not([data-theme="light"]) .theme-toggle .icon-moon { display: inline; }
}
@media (max-width: 640px) {
  .nav-links { display: none; }
}

/* ─── Hero ──────────────────────────────────────────────────────────────── */
.hero {
  position: relative;
  padding: 5.5rem 1.5rem 4.5rem;
  border-bottom: 1px solid var(--border);
  background-image:
    linear-gradient(var(--grid-line) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid-line) 1px, transparent 1px);
  background-size: 48px 48px;
}
.hero::after {
  content: ""; position: absolute; inset: 0; pointer-events: none;
  background: radial-gradient(ellipse at 20% 10%, transparent 40%, var(--bg) 85%);
}
.hero-inner {
  position: relative; z-index: 1;
  max-width: var(--max-w);
  margin: 0 auto;
  display: grid; grid-template-columns: minmax(0, 1.5fr) minmax(280px, 1fr);
  gap: 3rem; align-items: center;
}
.hero-title {
  font-size: clamp(2.4rem, 5.5vw, 3.9rem);
  font-weight: 800;
  line-height: 1.05;
  letter-spacing: -0.03em;
  margin: 0 0 1.25rem;
}
.hero-lead {
  font-size: 1.15rem; line-height: 1.6;
  color: var(--text-soft);
  max-width: 600px;
  margin: 0 0 1.1rem;
}
.hero-lead strong { color: var(--text); font-weight: 600; }
.hero-meta {
  font-family: var(--mono); font-size: .82rem; line-height: 1.6;
  color: var(--text-mute);
  margin: 0 0 2rem;
}
.hero-cta { display: flex; gap: .75rem; flex-wrap: wrap; }

.btn {
  display: inline-flex; align-items: center;
  padding: .72rem 1.25rem;
  font-size: .95rem; font-weight: 600;
  border-radius: var(--radius);
  border: 1px solid transparent;
  transition: transform .12s, background .15s, color .15s, border-color .15s;
}
.btn-primary { background: var(--text); color: var(--bg); }
.btn-primary:hover { background: var(--amber); color: #0a1628; transform: translateY(-1px); }
.btn-ghost { background: transparent; color: var(--text); border-color: var(--border-strong); }
.btn-ghost:hover { border-color: var(--text); color: var(--text); transform: translateY(-1px); }

.hero-stats {
  display: grid; grid-template-columns: 1fr 1fr; gap: 1px;
  background: var(--border);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow);
}
.stat {
  background: var(--surface);
  padding: 1.35rem 1.25rem;
  display: flex; flex-direction: column-reverse; gap: .3rem;
}
.stat dd {
  font-size: 2.1rem; font-weight: 800; letter-spacing: -0.03em; line-height: 1;
  color: var(--text);
}
.stat dt {
  font-size: .78rem; line-height: 1.4; color: var(--text-mute);
}
@media (max-width: 860px) {
  .hero-inner { grid-template-columns: 1fr; gap: 2.5rem; }
  .hero { padding: 4rem 1.5rem 3.5rem; }
}
@media (max-width: 420px) {
  .hero-stats { grid-template-columns: 1fr; }
}

/* ─── Sections ──────────────────────────────────────────────────────────── */
.section { padding: 5rem 1.5rem; }
.section-alt { background: var(--bg-alt); border-top: 1px solid var(--border); border-bottom: 1px solid var(--border); }
.section-inner { max-width: var(--max-w); margin: 0 auto; }
.section-head { margin-bottom: 3rem; max-width: var(--prose-w); }
.section-title { font-size: clamp(1.7rem, 3vw, 2.3rem); font-weight: 800; letter-spacing: -0.025em; margin: 0 0 .9rem; }
.section-desc { font-size: 1.05rem; color: var(--text-soft); }
@media (max-width: 640px) { .section { padding: 3.5rem 1rem; } }

/* ─── Groups ────────────────────────────────────────────────────────────── */
.group { margin-bottom: 4rem; }
.group:last-child { margin-bottom: 0; }
.group-head {
  display: grid; grid-template-columns: auto 1fr; column-gap: 1rem; row-gap: .25rem;
  align-items: baseline;
  padding-bottom: 1rem; margin-bottom: 1.5rem;
  border-bottom: 1px solid var(--border);
}
.group-index { font-family: var(--mono); font-size: .85rem; color: var(--accent); font-weight: 600; grid-row: 1 / span 2; align-self: start; padding-top: .35rem; }
.group-title { font-size: 1.35rem; font-weight: 700; }
.group-desc { font-size: .95rem; color: var(--text-mute); grid-column: 2; }

/* ─── Cards ─────────────────────────────────────────────────────────────── */
.cards {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(320px, 1fr)); gap: 1.4rem;
}
.card {
  position: relative;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 1.75rem 1.75rem 1.6rem;
  box-shadow: var(--shadow);
  display: flex; flex-direction: column; gap: 1rem;
  transition: transform .18s, box-shadow .18s, border-color .18s;
  overflow: hidden;
}
.card::before {
  content: ""; position: absolute; left: 0; top: 0; bottom: 0; width: 4px;
  background: var(--card-accent, var(--accent));
}
.card-ai { --card-accent: var(--ai); }
.card-de { --card-accent: var(--de); }
.card-ml { --card-accent: var(--ml); }
.card:hover { transform: translateY(-3px); box-shadow: var(--shadow-lg); border-color: var(--border-strong); }

.card-title { font-size: 1.25rem; font-weight: 700; margin-bottom: .2rem; }
.card-tag { font-family: var(--mono); font-size: .78rem; color: var(--text-mute); letter-spacing: .01em; }
.card-body { font-size: .95rem; line-height: 1.62; color: var(--text-soft); }

.finding {
  background: var(--surface-2);
  border-left: 3px solid var(--card-accent, var(--accent));
  border-radius: 0 var(--radius) var(--radius) 0;
  padding: .9rem 1rem .95rem;
}
.finding-label {
  font-family: var(--mono); font-size: .7rem; font-weight: 600;
  letter-spacing: .12em; text-transform: uppercase;
  color: var(--card-accent, var(--accent));
  margin-bottom: .4rem;
}
.finding p:last-child { font-size: .92rem; line-height: 1.6; color: var(--text); }

.metrics {
  display: flex; flex-wrap: wrap; gap: .75rem 1.5rem;
  padding-top: .25rem;
}
.metrics div { display: flex; flex-direction: column-reverse; gap: .15rem; flex: 1 1 auto; min-width: 88px; }
.metrics dd { font-family: var(--mono); font-size: .98rem; font-weight: 600; color: var(--text); letter-spacing: -0.01em; white-space: nowrap; }
.metrics dt { font-size: .72rem; line-height: 1.35; color: var(--text-mute); max-width: 150px; }

.chips { display: flex; flex-wrap: wrap; gap: .35rem; }
.chips li {
  font-family: var(--mono); font-size: .72rem; font-weight: 500;
  padding: .22rem .58rem; border-radius: 6px;
  background: var(--surface-2); color: var(--text-soft);
  border: 1px solid var(--border);
}

.card-links { display: flex; flex-wrap: wrap; gap: .5rem 1.25rem; margin-top: auto; padding-top: .35rem; font-size: .9rem; font-weight: 600; }
.card-links a::after { content: " →"; }
.card-links a.link-live { color: var(--live); }
.live {
  display: inline-block; font-family: var(--font);
  background: var(--live-bg); color: var(--live);
  padding: .1em .5em; border-radius: 99px;
  font-size: .68rem; font-weight: 700; letter-spacing: .05em; text-transform: uppercase;
  vertical-align: middle; margin-left: .2rem;
}

/* ─── Principles ────────────────────────────────────────────────────────── */
.principles { display: grid; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); gap: 1.4rem; }
.principle {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 1.75rem;
  box-shadow: var(--shadow);
}
.principle-num {
  display: inline-flex; align-items: center; justify-content: center;
  width: 34px; height: 34px; border-radius: 50%;
  background: var(--accent-bg); color: var(--accent);
  font-family: var(--mono); font-weight: 600; font-size: .9rem;
  margin-bottom: 1rem;
}
.principle h3 { font-size: 1.1rem; margin-bottom: .6rem; }
.principle p { font-size: .95rem; line-height: 1.62; color: var(--text-soft); }

/* ─── Stack ─────────────────────────────────────────────────────────────── */
.stack-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 2rem 2.5rem; }
.stack-col h3 {
  font-family: var(--mono); font-size: .74rem; font-weight: 600;
  letter-spacing: .12em; text-transform: uppercase;
  color: var(--text-mute); margin-bottom: .8rem;
  padding-bottom: .5rem; border-bottom: 1px solid var(--border);
}

/* ─── About ─────────────────────────────────────────────────────────────── */
.about-grid { display: grid; grid-template-columns: minmax(0, 1.4fr) minmax(280px, 1fr); gap: 3.5rem; align-items: start; }
.about-copy p:not(.eyebrow) { font-size: 1.02rem; line-height: 1.7; color: var(--text-soft); margin-bottom: 1.1rem; max-width: var(--prose-w); }
.about-facts { display: flex; flex-direction: column; gap: 1.4rem; padding-top: 2.6rem; }
.fact-label {
  font-family: var(--mono); font-size: .72rem; font-weight: 600;
  letter-spacing: .12em; text-transform: uppercase; color: var(--accent);
  margin-bottom: .5rem;
}
.fact li { font-size: .93rem; line-height: 1.55; color: var(--text-soft); margin-bottom: .7rem; }
.fact li strong { color: var(--text); font-weight: 600; }
@media (max-width: 800px) {
  .about-grid { grid-template-columns: 1fr; gap: 1.5rem; }
  .about-facts { padding-top: 0; }
}

/* ─── Contact ───────────────────────────────────────────────────────────── */
.contact-inner { text-align: center; }
.contact-inner .section-title { margin-bottom: .75rem; }
.contact-lead { font-size: 1.02rem; color: var(--text-soft); max-width: 560px; margin: 0 auto 2.25rem; }
.contact-links { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 1rem; max-width: 820px; margin: 0 auto; }
.contact-card {
  display: flex; flex-direction: column; gap: .3rem; align-items: center;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 1.35rem 1rem;
  color: var(--text);
  box-shadow: var(--shadow);
  transition: transform .15s, box-shadow .15s, border-color .15s;
}
.contact-card:hover { transform: translateY(-2px); box-shadow: var(--shadow-lg); border-color: var(--border-strong); color: var(--text); }
.contact-label { font-family: var(--mono); font-size: .7rem; letter-spacing: .12em; text-transform: uppercase; color: var(--accent); font-weight: 600; }
.contact-value { font-weight: 600; font-size: .95rem; word-break: break-all; }

/* ─── Footer ────────────────────────────────────────────────────────────── */
.footer { padding: 2rem 1.5rem; border-top: 1px solid var(--border); }
.footer-inner { max-width: var(--max-w); margin: 0 auto; text-align: center; }
.footer p { font-size: .84rem; color: var(--text-mute); }

/* ─── Motion preferences ────────────────────────────────────────────────── */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .card, .principle, .contact-card, .btn { transition: none; }
  .card:hover, .contact-card:hover, .btn:hover { transform: none; }
}