/* Design system for the public portfolio site.
   No external fonts, no CDN, no JS: the site must render identically offline and inside the CI
   container, and a portfolio page has no business making third-party requests.

   Palette: slate neutrals with a deep-blue accent. Light and dark are both first-class. */

:root {
  --bg: #f7f9fc;
  --surface: #ffffff;
  --ink: #0f172a;
  --body: #334155;
  --muted: #64748b;
  --line: #e2e8f0;
  --accent: #1e3a8a;
  --accent-2: #2563eb;
  --chip: #eef2ff;
  --chiptext: #1e3a8a;
  --shadow: 0 1px 2px rgba(15, 23, 42, .04), 0 8px 24px -12px rgba(15, 23, 42, .12);
  --radius: 14px;
  color-scheme: light dark;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0b1220;
    --surface: #111a2b;
    --ink: #e8edf7;
    --body: #c2ccdb;
    --muted: #8d9bb0;
    --line: #22304a;
    --accent: #93b4f5;
    --accent-2: #a9c6ff;
    --chip: #1a2740;
    --chiptext: #bcd2ff;
    --shadow: 0 1px 2px rgba(0, 0, 0, .3), 0 12px 30px -16px rgba(0, 0, 0, .6);
  }
}

*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--body);
  font: 400 1.0625rem/1.65 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

.wrap { max-width: 64rem; margin: 0 auto; padding: 0 1.25rem; }

a { color: var(--accent-2); text-underline-offset: 3px; }
h1, h2, h3 { color: var(--ink); line-height: 1.18; letter-spacing: -.015em; margin: 0; }
p, ul, ol, dl, table, pre, blockquote { margin: 0 0 1rem; }

.skip-link { position: absolute; left: -9999px; top: 0; }
.skip-link:focus {
  left: 1rem; top: 1rem; z-index: 20; background: var(--surface);
  padding: .5rem .75rem; border-radius: 8px; border: 1px solid var(--line);
}

/* ---------- header ---------- */
.site-header {
  position: sticky; top: 0; z-index: 10;
  backdrop-filter: blur(10px);
  background: color-mix(in srgb, var(--bg) 82%, transparent);
  border-bottom: 1px solid var(--line);
}
.nav { display: flex; align-items: center; justify-content: space-between; gap: 1rem; height: 64px; }
.brand {
  display: flex; align-items: center; gap: .55rem;
  font-weight: 650; color: var(--ink); text-decoration: none; letter-spacing: -.01em;
}
.brand .mark {
  width: 26px; height: 26px; border-radius: 8px;
  background: linear-gradient(135deg, var(--accent), #3b82f6);
  display: grid; place-items: center; color: #fff; font-size: .78rem; font-weight: 700;
}
.site-nav ul { display: flex; gap: 1.15rem; list-style: none; margin: 0; padding: 0; font-size: .94rem; }
.site-nav a { color: var(--muted); text-decoration: none; }
.site-nav a:hover, .site-nav a[aria-current="page"] { color: var(--ink); }

/* ---------- hero ---------- */
.hero { padding: 4.5rem 0 3rem; }
.eyebrow {
  display: inline-flex; align-items: center; gap: .5rem;
  font-size: .8rem; font-weight: 600; letter-spacing: .06em; text-transform: uppercase;
  color: var(--chiptext); background: var(--chip); padding: .35rem .7rem; border-radius: 999px;
}
.hero h1 { font-size: clamp(2rem, 5vw, 3rem); margin: 1.1rem 0 .9rem; font-weight: 700; }
.hero .lead { font-size: clamp(1.05rem, 2.1vw, 1.22rem); max-width: 46rem; margin: 0 0 1rem; }
.hero .where { color: var(--muted); font-size: .96rem; margin: 0 0 1.4rem; }
.chips { display: flex; flex-wrap: wrap; gap: .45rem; margin: 0 0 1.8rem; padding: 0; list-style: none; }
.chips li {
  font-size: .82rem; font-weight: 550; color: var(--chiptext); background: var(--chip);
  border: 1px solid color-mix(in srgb, var(--chiptext) 12%, transparent);
  padding: .3rem .65rem; border-radius: 999px;
}
.cta { display: flex; flex-wrap: wrap; gap: .65rem; }
.btn {
  display: inline-flex; align-items: center; gap: .45rem;
  padding: .62rem 1.05rem; border-radius: 10px;
  font-size: .95rem; font-weight: 600; text-decoration: none;
  border: 1px solid transparent; transition: .15s ease;
}
.btn-primary { background: var(--accent); color: #fff; }
.btn-primary:hover { background: var(--accent-2); }
.btn-ghost { border-color: var(--line); color: var(--ink); background: var(--surface); }
.btn-ghost:hover { border-color: var(--accent-2); }

/* ---------- sections ---------- */
.section { padding: 2.6rem 0; }
.section-head {
  display: flex; align-items: baseline; justify-content: space-between;
  gap: 1rem; margin-bottom: 1.3rem; flex-wrap: wrap;
}
.section-head h2 { font-size: 1.35rem; font-weight: 650; }
.section-head p { margin: 0; color: var(--muted); font-size: .92rem; }

.grid { display: grid; gap: 1rem; grid-template-columns: repeat(auto-fit, minmax(15.5rem, 1fr)); }

.card {
  background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 1.25rem; box-shadow: var(--shadow);
  transition: transform .16s ease, border-color .16s ease;
}
.card:hover { transform: translateY(-2px); border-color: color-mix(in srgb, var(--accent-2) 35%, var(--line)); }
.card h3 { font-size: 1rem; font-weight: 650; margin: 0 0 .4rem; display: flex; align-items: center; gap: .55rem; }
.card p { margin: 0; font-size: .94rem; line-height: 1.55; }
.card .meta { color: var(--muted); font-size: .86rem; margin: .1rem 0 .5rem; }

.ico {
  flex: 0 0 auto; width: 30px; height: 30px; border-radius: 9px;
  display: grid; place-items: center; background: var(--chip); color: var(--chiptext);
}
.ico svg { width: 16px; height: 16px; }

.tier {
  display: inline-block; margin-top: .85rem;
  font-size: .72rem; font-weight: 600; letter-spacing: .03em; text-transform: uppercase;
  color: var(--chiptext); background: var(--chip); padding: .2rem .5rem; border-radius: 6px;
}
.card-link {
  display: inline-flex; align-items: center; gap: .35rem;
  margin-top: .9rem; font-size: .86rem; font-weight: 600;
  color: var(--accent-2); text-decoration: none;
}
.card-link svg { width: 13px; height: 13px; }
.card-link:hover { text-decoration: underline; text-underline-offset: 3px; }
.tier + .card-link { margin-left: .55rem; margin-top: .85rem; }

/* A call to action inside a prose page (the GitHub button on an evidence page). */
.evidence-cta { margin: 1.4rem 0 1.9rem; }
.tier-proposed { background: color-mix(in srgb, var(--muted) 14%, transparent); color: var(--muted); }

.badge {
  display: inline-flex; align-items: center; gap: .45rem; margin-top: .8rem;
  font-size: .78rem; font-weight: 600; color: var(--chiptext);
  border: 1px solid color-mix(in srgb, var(--chiptext) 22%, transparent);
  padding: .28rem .55rem; border-radius: 999px;
}
.badge svg { width: 13px; height: 13px; }

/* ---------- evidence band ---------- */
.band {
  background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 1.4rem 1.5rem; display: flex; gap: 1.2rem;
  align-items: center; justify-content: space-between; flex-wrap: wrap;
}
.band h2 { font-size: 1.1rem; margin: 0 0 .25rem; }
.band p { margin: 0; font-size: .94rem; max-width: 40rem; }

/* ---------- prose pages (evidence, 404) ---------- */
.page { padding: 3rem 0 2rem; max-width: 46rem; }
.page h1 { font-size: clamp(1.7rem, 3.6vw, 2.3rem); margin-bottom: .6rem; }
.lede { font-size: 1.08rem; color: var(--muted); margin-bottom: 1.6rem; }
.page h2 { font-size: 1.25rem; margin: 2.2rem 0 .7rem; }
.page h3 { font-size: 1.05rem; margin: 1.6rem 0 .5rem; }
.page ul, .page ol { padding-left: 1.2rem; }
.page li { margin-bottom: .35rem; }
.page-meta { color: var(--muted); font-size: .9rem; margin-top: 2rem; }

table { border-collapse: collapse; width: 100%; font-size: .93rem; }
th, td { text-align: left; padding: .45rem .6rem; border-bottom: 1px solid var(--line); vertical-align: top; }
th { font-weight: 650; color: var(--ink); }

pre {
  overflow-x: auto; padding: .85rem 1rem;
  border: 1px solid var(--line); border-radius: 8px; font-size: .88rem;
  background: var(--surface);
}
code { font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace; font-size: .94em; }
pre code { font-size: inherit; }

blockquote {
  margin-left: 0; padding-left: 1rem; border-left: 3px solid var(--line); color: var(--muted);
}

/* ---------- footer ---------- */
.site-footer {
  border-top: 1px solid var(--line); margin-top: 2.5rem; padding: 1.6rem 0 2.4rem;
  color: var(--muted); font-size: .9rem;
}
.site-footer .wrap { display: flex; justify-content: space-between; gap: 1rem; flex-wrap: wrap; }
.site-footer p { margin: 0; }

@media (max-width: 34rem) {
  .site-nav ul { display: none; }
  .hero { padding: 3rem 0 2rem; }
  .card { padding: 1.1rem; }
  .wrap { padding: 0 1rem; }
}