:root {
  --bg: #0f1419;
  --surface: #1a222c;
  --surface2: #243040;
  --text: #e8eef4;
  --muted: #9aabbc;
  --accent: #3dd6c3;
  --accent-dim: #2a9f90;
  --warn: #f0b429;
  --border: #2e3a48;
  --radius: 10px;
  --font: "Segoe UI", system-ui, -apple-system, sans-serif;
  --mono: ui-monospace, "Cascadia Code", Menlo, monospace;
  --max: 720px;
  --wide: 960px;
}

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

html { scroll-behavior: smooth; }

body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.65;
  min-height: 100vh;
}

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

.wrap { max-width: var(--wide); margin: 0 auto; padding: 0 1.25rem; }
.narrow { max-width: var(--max); }

/* Header */
.site-header {
  border-bottom: 1px solid var(--border);
  background: rgba(15, 20, 25, 0.92);
  backdrop-filter: blur(8px);
  position: sticky;
  top: 0;
  z-index: 20;
}
.site-header .inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.9rem 0;
  gap: 1rem;
}
.logo {
  font-weight: 700;
  font-size: 1.15rem;
  color: var(--text);
  letter-spacing: -0.02em;
}
.logo span { color: var(--accent); }
.logo:hover { text-decoration: none; }
nav { display: flex; gap: 1.25rem; flex-wrap: wrap; }
nav a { color: var(--muted); font-size: 0.95rem; }
nav a:hover { color: var(--accent); }

/* Hero */
.hero {
  padding: 3.5rem 0 2.5rem;
  border-bottom: 1px solid var(--border);
}
.hero .eyebrow {
  display: inline-block;
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--accent);
  font-weight: 600;
  margin-bottom: 0.75rem;
}
.hero h1 {
  font-size: clamp(1.85rem, 4vw, 2.6rem);
  line-height: 1.2;
  letter-spacing: -0.03em;
  max-width: 18ch;
  margin-bottom: 1rem;
}
.hero .lede {
  font-size: 1.15rem;
  color: var(--muted);
  max-width: 42ch;
  margin-bottom: 1.75rem;
}
.cta-row { display: flex; flex-wrap: wrap; gap: 0.75rem; }
.btn {
  display: inline-block;
  padding: 0.7rem 1.2rem;
  border-radius: var(--radius);
  font-weight: 600;
  font-size: 0.95rem;
  border: 1px solid transparent;
  cursor: pointer;
}
.btn:hover { text-decoration: none; }
.btn-primary {
  background: var(--accent);
  color: #0a1210;
}
.btn-primary:hover { background: #5ee0d0; }
.btn-ghost {
  background: transparent;
  border-color: var(--border);
  color: var(--text);
}
.btn-ghost:hover { border-color: var(--accent); color: var(--accent); }

/* Sections */
section { padding: 2.75rem 0; }
section h2 {
  font-size: 1.45rem;
  margin-bottom: 0.5rem;
  letter-spacing: -0.02em;
}
.section-intro {
  color: var(--muted);
  margin-bottom: 1.5rem;
  max-width: 50ch;
}

.grid-3 {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1rem;
}
.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.25rem;
}
.card h3 { font-size: 1.05rem; margin-bottom: 0.4rem; }
.card p { color: var(--muted); font-size: 0.95rem; }

/* Article list */
.article-list { list-style: none; display: flex; flex-direction: column; gap: 0.75rem; }
.article-list li {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  transition: border-color 0.15s;
}
.article-list li:hover { border-color: var(--accent-dim); }
.article-list a {
  display: block;
  padding: 1.1rem 1.25rem;
  color: var(--text);
}
.article-list a:hover { text-decoration: none; }
.article-list .meta {
  font-size: 0.8rem;
  color: var(--muted);
  margin-bottom: 0.25rem;
}
.article-list .title {
  font-weight: 600;
  font-size: 1.05rem;
}

/* Article page */
.article-header {
  padding: 2.5rem 0 1.5rem;
  border-bottom: 1px solid var(--border);
}
.article-header .meta {
  color: var(--muted);
  font-size: 0.9rem;
  margin-bottom: 0.75rem;
}
.article-header h1 {
  font-size: clamp(1.6rem, 3.5vw, 2.2rem);
  line-height: 1.25;
  letter-spacing: -0.025em;
  margin-bottom: 0.75rem;
}
.article-header .dek {
  color: var(--muted);
  font-size: 1.1rem;
  max-width: 52ch;
}

.article-body {
  padding: 2rem 0 3rem;
}
.article-body h2 {
  margin-top: 2rem;
  margin-bottom: 0.65rem;
  font-size: 1.3rem;
}
.article-body h3 {
  margin-top: 1.5rem;
  margin-bottom: 0.5rem;
  font-size: 1.1rem;
}
.article-body p { margin-bottom: 1rem; }
.article-body ul, .article-body ol {
  margin: 0 0 1.1rem 1.25rem;
  color: var(--text);
}
.article-body li { margin-bottom: 0.4rem; }
.article-body li::marker { color: var(--accent); }

.prompt-box {
  background: var(--surface);
  border: 1px solid var(--border);
  border-left: 3px solid var(--accent);
  border-radius: var(--radius);
  padding: 1rem 1.1rem;
  margin: 1rem 0 1.25rem;
  font-family: var(--mono);
  font-size: 0.88rem;
  white-space: pre-wrap;
  color: #c5d4e0;
  line-height: 1.55;
}

.callout {
  background: var(--surface2);
  border-radius: var(--radius);
  padding: 1rem 1.15rem;
  margin: 1.25rem 0;
  border: 1px solid var(--border);
}
.callout strong { color: var(--warn); }

.article-cta {
  margin-top: 2.5rem;
  padding: 1.5rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
}
.article-cta h2 { margin-top: 0; }

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

@media (max-width: 560px) {
  .hero { padding: 2.5rem 0 2rem; }
  nav { gap: 0.85rem; }
}