:root {
  --bg: #0b1020;
  --bg-alt: #111833;
  --surface: #161f3d;
  --border: #26305a;
  --text: #e7eaf6;
  --muted: #a9b0cf;
  --accent: #8b7dff;
  --accent-strong: #6d5dfc;
  --gate: #33d39a;
  --radius: 14px;
  --max: 1120px;
  color-scheme: dark;
}

@media (prefers-color-scheme: light) {
  :root {
    --bg: #f7f8fc;
    --bg-alt: #eef0f8;
    --surface: #ffffff;
    --border: #d9ddee;
    --text: #141a33;
    --muted: #4a5276;
    --accent: #5240e6;
    --accent-strong: #4a37e0;
    --gate: #0f8a5f;
    color-scheme: light;
  }
}

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

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

body {
  margin: 0;
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  font-size: 1.0625rem;
  line-height: 1.6;
  background: var(--bg);
  color: var(--text);
}

a { color: var(--accent); }
a:focus-visible, .button:focus-visible { outline: 3px solid var(--accent); outline-offset: 3px; border-radius: 6px; }

code { font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace; font-size: 0.9em; }

.container { width: min(100% - 2.5rem, var(--max)); margin-inline: auto; }

.skip-link {
  position: absolute; left: 1rem; top: -3rem;
  background: var(--accent-strong); color: #fff;
  padding: 0.5rem 1rem; border-radius: 8px; z-index: 10;
}
.skip-link:focus { top: 1rem; }

/* Header */
.site-header {
  position: sticky; top: 0; z-index: 5;
  background: color-mix(in srgb, var(--bg) 85%, transparent);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
}
.header-inner { display: flex; align-items: center; justify-content: space-between; gap: 1rem; padding-block: 0.9rem; }
.brand { display: inline-flex; align-items: center; gap: 0.6rem; font-weight: 700; color: var(--text); text-decoration: none; }
.brand-mark {
  display: grid; place-items: center; width: 1.9rem; height: 1.9rem;
  border-radius: 8px; background: var(--accent-strong); color: #fff; font-size: 1rem;
}
.nav-list { display: flex; gap: 1.4rem; list-style: none; margin: 0; padding: 0; }
.nav-list a { color: var(--muted); text-decoration: none; font-size: 0.95rem; }
.nav-list a:hover { color: var(--text); }
@media (max-width: 640px) { .nav-list { display: none; } }

/* Hero */
.hero {
  padding-block: clamp(4rem, 10vw, 7.5rem);
  background:
    radial-gradient(60rem 30rem at 85% -10%, color-mix(in srgb, var(--accent) 22%, transparent), transparent 70%),
    radial-gradient(40rem 25rem at -10% 110%, color-mix(in srgb, var(--gate) 12%, transparent), transparent 70%);
}
.eyebrow { color: var(--accent); font-weight: 600; letter-spacing: 0.06em; text-transform: uppercase; font-size: 0.85rem; margin: 0 0 1rem; }
h1 { font-size: clamp(2.2rem, 5.5vw, 3.8rem); line-height: 1.1; margin: 0 0 1.4rem; letter-spacing: -0.02em; }
.accent { color: var(--accent); }
.lede { font-size: clamp(1.1rem, 2vw, 1.3rem); color: var(--muted); max-width: 46rem; margin: 0 0 2rem; }

.hero-actions { display: flex; flex-wrap: wrap; gap: 0.8rem; }
.button {
  display: inline-block; padding: 0.8rem 1.4rem; border-radius: 10px;
  font-weight: 600; text-decoration: none; border: 1px solid transparent;
}
.button.primary { background: var(--accent-strong); color: #fff; }
.button.primary:hover { filter: brightness(1.1); }
.button.ghost { border-color: var(--border); color: var(--text); }
.button.ghost:hover { border-color: var(--accent); }

.hero-tags { display: flex; flex-wrap: wrap; gap: 0.5rem; list-style: none; padding: 0; margin: 2.2rem 0 0; }
.hero-tags li {
  padding: 0.25rem 0.75rem; border: 1px solid var(--border); border-radius: 999px;
  color: var(--muted); font-size: 0.85rem;
}

/* Sections */
.section { padding-block: clamp(3.5rem, 8vw, 6rem); }
.section.alt { background: var(--bg-alt); }
h2 { font-size: clamp(1.7rem, 3.5vw, 2.4rem); line-height: 1.2; margin: 0 0 0.8rem; letter-spacing: -0.01em; }
h3 { font-size: 1.1rem; margin: 0 0 0.4rem; }
.section-lede { color: var(--muted); max-width: 44rem; margin: 0 0 2.5rem; }

/* Workflow steps */
.steps {
  list-style: none; margin: 0; padding: 0; counter-reset: step;
  display: grid; gap: 1rem; grid-template-columns: repeat(auto-fit, minmax(14rem, 1fr));
}
.step {
  counter-increment: step; position: relative;
  background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 1.3rem 1.3rem 1.2rem;
}
.step::before {
  content: counter(step, decimal-leading-zero);
  display: block; color: var(--accent); font-weight: 700; font-size: 0.85rem; margin-bottom: 0.4rem;
}
.step-name { display: block; font-weight: 700; font-size: 1.1rem; margin-bottom: 0.3rem; }
.step p { margin: 0; color: var(--muted); font-size: 0.97rem; }
.step.gate { border-color: var(--gate); }
.step.gate::before { color: var(--gate); }

/* Evidence */
.split { display: grid; gap: 2.5rem; grid-template-columns: 1.1fr 1fr; align-items: center; }
@media (max-width: 860px) { .split { grid-template-columns: 1fr; } }
.split p { color: var(--muted); }
.evidence-card {
  margin: 0; background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 1.4rem;
}
.evidence-card figcaption { font-weight: 600; color: var(--muted); font-size: 0.85rem; text-transform: uppercase; letter-spacing: 0.06em; margin-bottom: 0.8rem; }
.evidence-card ul { list-style: none; margin: 0; padding: 0; display: grid; gap: 0.6rem; }
.evidence-card li {
  display: flex; flex-direction: column; gap: 0.1rem;
  padding: 0.7rem 0.9rem; border-radius: 10px; background: var(--bg-alt);
}
.evidence-card code { color: var(--accent); }
.evidence-card span { color: var(--muted); font-size: 0.9rem; }

/* Cards */
.cards { display: grid; gap: 1rem; grid-template-columns: repeat(auto-fit, minmax(17rem, 1fr)); }
.card { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 1.4rem; }
.card p { margin: 0; color: var(--muted); }

/* Principles */
.principles { display: grid; gap: 2rem; grid-template-columns: repeat(auto-fit, minmax(15rem, 1fr)); margin-top: 2rem; }
.principles h3 { color: var(--text); }
.principles p { margin: 0; color: var(--muted); }

/* Footer */
.site-footer { border-top: 1px solid var(--border); padding-block: 2rem; color: var(--muted); font-size: 0.9rem; }
.footer-inner { display: flex; flex-wrap: wrap; justify-content: space-between; gap: 0.5rem; }
.footer-inner p { margin: 0; }