:root {
  --bg: #0b0d10;
  --bg-elev: #14171c;
  --fg: #e8e6e1;
  --fg-dim: #9aa0a8;
  --fg-faint: #5b6168;
  --accent: #d4b483;
  --rule: #1f242b;
  --link: #c9b88f;
  --link-hover: #efdfb6;
  --max: 68ch;
  --max-wide: 84ch;
  --pad: clamp(1rem, 4vw, 2rem);
}

@media (prefers-color-scheme: light) {
  :root {
    --bg: #fbfaf6;
    --bg-elev: #f3f1ea;
    --fg: #1a1d22;
    --fg-dim: #4a5159;
    --fg-faint: #8a8f97;
    --accent: #8a6a2e;
    --rule: #e3dfd3;
    --link: #6a5018;
    --link-hover: #3a2c0a;
  }
}

* { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; }

body {
  background: var(--bg);
  color: var(--fg);
  font-family: ui-serif, Charter, "Iowan Old Style", "Source Serif Pro", Georgia, serif;
  font-size: 18px;
  line-height: 1.6;
  margin: 0;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
}

main {
  max-width: var(--max-wide);
  margin: 0 auto;
  padding: 0 var(--pad);
}

section {
  padding: 3rem 0;
  border-bottom: 1px solid var(--rule);
}

section:last-of-type { border-bottom: none; }

h1, h2, h3 {
  font-family: ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  font-weight: 600;
  letter-spacing: -0.01em;
  line-height: 1.2;
  margin: 0 0 0.5em;
}

h1 { font-size: clamp(2rem, 5vw, 3rem); letter-spacing: -0.02em; }
h2 { font-size: clamp(1.4rem, 3vw, 1.85rem); margin-top: 0; }
h3 { font-size: 1.1rem; margin-top: 1.5em; }

p { margin: 0 0 1em; max-width: var(--max); }

a {
  color: var(--link);
  text-decoration: underline;
  text-underline-offset: 3px;
  text-decoration-thickness: 1px;
}
a:hover { color: var(--link-hover); }
a:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
  border-radius: 2px;
}

code, pre {
  font-family: ui-monospace, "JetBrains Mono", "SF Mono", Menlo, Consolas, monospace;
  font-size: 0.92em;
}

pre {
  background: var(--bg-elev);
  border: 1px solid var(--rule);
  border-radius: 6px;
  padding: 1rem 1.25rem;
  overflow-x: auto;
  font-size: 0.85em;
  line-height: 1.5;
  max-width: var(--max);
}

abbr { text-decoration: underline dotted; cursor: help; }

cite { font-style: italic; }

/* header */
header {
  border-bottom: 1px solid var(--rule);
  background: var(--bg);
  position: sticky;
  top: 0;
  z-index: 10;
  backdrop-filter: blur(8px);
}

nav {
  max-width: var(--max-wide);
  margin: 0 auto;
  padding: 0.75rem var(--pad);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
}

.brand {
  font-family: ui-sans-serif, system-ui, sans-serif;
  font-weight: 600;
  color: var(--fg);
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 1.05rem;
  letter-spacing: -0.01em;
}
.brand svg { color: var(--accent); }

nav ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  gap: 1.25rem;
  flex-wrap: wrap;
  font-family: ui-sans-serif, system-ui, sans-serif;
  font-size: 0.95rem;
}
nav a { color: var(--fg-dim); text-decoration: none; }
nav a:hover { color: var(--fg); }

/* hero */
.hero { padding-top: 4rem; padding-bottom: 4rem; }
.hero h1 { margin-bottom: 0.6em; }
.lede { font-size: 1.15rem; color: var(--fg-dim); max-width: var(--max); }
.status {
  font-family: ui-monospace, monospace;
  font-size: 0.8rem;
  color: var(--fg-faint);
  margin-top: 1.5rem;
  letter-spacing: 0.02em;
}

.cta-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin: 1.5rem 0 0;
}

.cta {
  display: inline-block;
  font-family: ui-sans-serif, system-ui, sans-serif;
  font-size: 0.95rem;
  font-weight: 500;
  padding: 0.6rem 1.2rem;
  border: 1px solid var(--rule);
  border-radius: 6px;
  background: var(--bg-elev);
  color: var(--fg);
  text-decoration: none;
  transition: border-color 120ms ease;
}
.cta:hover { border-color: var(--accent); color: var(--fg); }
.cta.primary {
  background: var(--accent);
  color: var(--bg);
  border-color: var(--accent);
}
.cta.primary:hover { background: var(--link-hover); border-color: var(--link-hover); }

/* how-it-works numbered list */
ol.how {
  list-style: none;
  padding: 0;
  margin: 1.5rem 0;
  counter-reset: step;
  display: grid;
  gap: 1.25rem;
}
ol.how li {
  counter-increment: step;
  padding-left: 3rem;
  position: relative;
}
ol.how li::before {
  content: counter(step);
  position: absolute;
  left: 0;
  top: 0.1rem;
  width: 2rem;
  height: 2rem;
  border: 1px solid var(--rule);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: ui-monospace, monospace;
  font-size: 0.85rem;
  color: var(--accent);
  background: var(--bg-elev);
}
ol.how h3 { margin: 0 0 0.2em; font-size: 1rem; }
ol.how p { margin: 0; color: var(--fg-dim); }

.algo-h { margin-top: 2.5rem; }

/* not-this list */
ul.not {
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  gap: 0.85rem;
  max-width: var(--max);
}
ul.not li {
  padding-left: 1.5rem;
  position: relative;
  color: var(--fg-dim);
}
ul.not li::before {
  content: "×";
  position: absolute;
  left: 0;
  top: -0.1rem;
  color: var(--accent);
  font-weight: 600;
}
ul.not strong { color: var(--fg); font-weight: 600; }

/* download grid */
.downloads {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 1rem;
  margin: 1.5rem 0;
}
.downloads article {
  border: 1px solid var(--rule);
  border-radius: 8px;
  padding: 1.25rem;
  background: var(--bg-elev);
}
.downloads h3 { margin-top: 0; }
.downloads p { color: var(--fg-dim); font-size: 0.95rem; }
.downloads .cta { font-size: 0.88rem; padding: 0.45rem 0.9rem; }

/* refs */
ul.refs {
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  gap: 0.75rem;
}
ul.refs li {
  padding-left: 1.25rem;
  position: relative;
  font-size: 0.95rem;
  color: var(--fg-dim);
  max-width: var(--max);
}
ul.refs li::before {
  content: "§";
  position: absolute;
  left: 0;
  color: var(--accent);
}

.small { font-size: 0.85rem; color: var(--fg-faint); }

/* footer */
footer {
  border-top: 1px solid var(--rule);
  margin-top: 2rem;
  padding: 2rem var(--pad) 3rem;
  text-align: center;
  font-family: ui-sans-serif, system-ui, sans-serif;
  font-size: 0.9rem;
  color: var(--fg-dim);
}
footer p { margin: 0.3em auto; max-width: var(--max-wide); }
footer a { color: var(--fg-dim); }
footer a:hover { color: var(--fg); }

/* respect motion preferences — already minimal but explicit */
@media (prefers-reduced-motion: reduce) {
  * { transition: none !important; animation: none !important; }
}

/* print */
@media print {
  header, footer, .cta-row { display: none; }
  body { background: #fff; color: #000; }
  section { border-color: #ccc; }
}