/* ============================================================
   Design tokens
   Concept: an engineer's logbook — dark drafting-table graphite,
   blueprint-teal ink, amber annotation flags, monospace headers
   ============================================================ */
:root {
  --bg: #14181d;
  --surface: #1c232b;
  --surface-raised: #232b34;
  --paper: #ece7da;
  --ink: #e7e2d6;
  --ink-dim: #9ca3ad;
  --ink-faint: #6b727c;
  --teal: #4fa89c;
  --teal-dim: #3a7b72;
  --amber: #e0a23d;
  --line: #2e363f;

  --font-display: 'JetBrains Mono', 'SFMono-Regular', Consolas, monospace;
  --font-body: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;

  --maxw: 880px;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--font-body);
  font-size: 17px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

/* Faint graph-paper texture, used sparingly behind hero sections */
.graph {
  background-image:
    linear-gradient(var(--line) 1px, transparent 1px),
    linear-gradient(90deg, var(--line) 1px, transparent 1px);
  background-size: 32px 32px;
  background-position: -1px -1px;
  position: relative;
}
.graph::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, rgba(20,24,29,0.2), var(--bg) 92%);
  pointer-events: none;
}

a { color: var(--teal); text-decoration: none; }
a:hover { text-decoration: underline; }
a:focus-visible, button:focus-visible { outline: 2px solid var(--amber); outline-offset: 3px; }

h1, h2, h3 {
  font-family: var(--font-display);
  font-weight: 600;
  letter-spacing: -0.01em;
  color: var(--ink);
  margin: 0 0 0.5em;
}

.wrap {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 24px;
}

/* -------- Nav -------- */
.site-nav {
  border-bottom: 1px solid var(--line);
  position: sticky;
  top: 0;
  background: rgba(20, 24, 29, 0.92);
  backdrop-filter: blur(6px);
  z-index: 10;
}
.site-nav .wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 16px;
  padding-bottom: 16px;
}
.site-nav .brand {
  font-family: var(--font-display);
  font-size: 15px;
  color: var(--ink);
  letter-spacing: 0.02em;
}
.site-nav .brand:hover { text-decoration: none; color: var(--teal); }
.site-nav ul {
  list-style: none;
  display: flex;
  gap: 24px;
  margin: 0;
  padding: 0;
  font-size: 14px;
}
.site-nav a { color: var(--ink-dim); }
.site-nav a:hover { color: var(--ink); text-decoration: none; }
.site-nav a.active { color: var(--teal); }

/* -------- Stamp: the signature element -------- */
.stamp {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  border: 1px dashed var(--teal-dim);
  color: var(--teal);
  font-family: var(--font-display);
  font-size: 12px;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  padding: 5px 10px;
  transform: rotate(-1deg);
  white-space: nowrap;
}
.stamp.amber { border-color: var(--amber); color: var(--amber); }

/* -------- Hero -------- */
.hero { padding: 96px 0 72px; }
.hero .eyebrow {
  font-family: var(--font-display);
  color: var(--teal);
  font-size: 13px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin-bottom: 18px;
  display: block;
}
.hero h1 {
  font-size: 44px;
  line-height: 1.15;
  max-width: 14ch;
}
.hero p.lede {
  font-size: 19px;
  color: var(--ink-dim);
  max-width: 54ch;
  margin: 18px 0 32px;
}
.hero .actions { display: flex; gap: 14px; flex-wrap: wrap; }

.btn {
  display: inline-block;
  padding: 11px 20px;
  font-family: var(--font-display);
  font-size: 13px;
  letter-spacing: 0.03em;
  border: 1px solid var(--teal);
  color: var(--teal);
}
.btn:hover { background: var(--teal); color: var(--bg); text-decoration: none; }
.btn.ghost { border-color: var(--line); color: var(--ink-dim); }
.btn.ghost:hover { border-color: var(--ink-dim); background: none; color: var(--ink); }

/* -------- Sections -------- */
section { padding: 56px 0; }
section + section { border-top: 1px solid var(--line); }
.section-head { display: flex; align-items: baseline; justify-content: space-between; margin-bottom: 32px; gap: 16px; flex-wrap: wrap; }
.section-head h2 { font-size: 22px; }
.section-head .see-all { font-family: var(--font-display); font-size: 13px; }

/* -------- Project index / cards -------- */
.log-entry {
  display: grid;
  grid-template-columns: 96px 1fr;
  gap: 20px;
  padding: 24px 0;
  border-top: 1px solid var(--line);
}
.log-entry:first-of-type { border-top: none; }
.log-entry .idx {
  font-family: var(--font-display);
  color: var(--ink-faint);
  font-size: 13px;
  padding-top: 3px;
}
.log-entry h3 { font-size: 19px; margin-bottom: 6px; }
.log-entry h3 a { color: var(--ink); }
.log-entry h3 a:hover { color: var(--teal); text-decoration: none; }
.log-entry .meta { display: flex; gap: 8px; flex-wrap: wrap; margin: 8px 0 10px; }
.log-entry .tag {
  font-family: var(--font-display);
  font-size: 11px;
  color: var(--ink-dim);
  border: 1px solid var(--line);
  padding: 3px 8px;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}
.log-entry p { color: var(--ink-dim); margin: 0; }

/* -------- Blog list -------- */
.post-row {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  padding: 16px 0;
  border-top: 1px solid var(--line);
  gap: 16px;
}
.post-row:first-of-type { border-top: none; }
.post-row a { color: var(--ink); font-size: 16px; }
.post-row a:hover { color: var(--teal); text-decoration: none; }
.post-row time { font-family: var(--font-display); font-size: 12px; color: var(--ink-faint); white-space: nowrap; }

/* -------- Case study page -------- */
.case-header { padding: 64px 0 40px; }
.case-header .stamp { margin-bottom: 20px; }
.case-header h1 { font-size: 36px; max-width: 22ch; }
.case-meta {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: 20px;
  margin-top: 32px;
  padding-top: 28px;
  border-top: 1px solid var(--line);
}
.case-meta dt {
  font-family: var(--font-display);
  font-size: 11px;
  color: var(--teal);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  margin-bottom: 4px;
}
.case-meta dd { margin: 0; color: var(--ink-dim); font-size: 14px; }

.case-body h2 {
  font-size: 20px;
  color: var(--teal);
  margin-top: 0;
}
.case-body .ruler {
  border: none;
  border-top: 1px dashed var(--line);
  margin: 40px 0;
}
.case-body p { color: var(--ink-dim); }
.case-body ul { color: var(--ink-dim); padding-left: 20px; }
.case-body .callout {
  background: var(--surface);
  border-left: 2px solid var(--amber);
  padding: 16px 20px;
  font-size: 15px;
  color: var(--ink);
}

/* -------- Footer -------- */
footer {
  border-top: 1px solid var(--line);
  padding: 40px 0 60px;
  font-size: 13px;
  color: var(--ink-faint);
  font-family: var(--font-display);
}
footer .links { display: flex; gap: 18px; margin-top: 10px; flex-wrap: wrap; }

/* -------- Responsive -------- */
@media (max-width: 640px) {
  .hero { padding: 64px 0 48px; }
  .hero h1 { font-size: 32px; }
  .log-entry { grid-template-columns: 1fr; gap: 6px; }
  .site-nav ul { gap: 14px; }
}

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