/* BIM Reference Library — dark navy blueprint + cyan glow.
   Inspired by a blueprint-grid / city-skyline look. No photos. */
:root {
  color-scheme: dark;
  --bg: #05080c;
  --bg-2: #0a1218;
  --surface: rgba(8, 16, 26, 0.78);
  --surface-2: rgba(12, 24, 36, 0.92);
  --fg: #e8f4f8;
  --muted: #93a8b4;
  --line: rgba(80, 210, 240, 0.28);
  --cyan: #3de8ff;
  --cyan-2: #7af0ff;
  --cyan-dim: rgba(61, 232, 255, 0.14);
  --cyan-glow: rgba(61, 232, 255, 0.45);
  --navy: #0b1c2e;
  --ink: #041018;
  --accent: var(--cyan);
  --olive: #8fd9b4;
  --pro: #7ee0b0;
  --con: #c9d6dc;
  --warn: #ffc857;
  --focus: #7af0ff;
  --btn: rgba(61, 232, 255, 0.12);
  --btn-h: rgba(61, 232, 255, 0.22);
  --radius: 18px;
  --display: "Rajdhani", "Segoe UI", sans-serif;
  --body: "IBM Plex Sans", "Segoe UI", system-ui, sans-serif;
  --mono: "IBM Plex Mono", ui-monospace, monospace;
}

*, *::before, *::after { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  background: var(--bg);
  color: var(--fg);
  font-family: var(--body);
  font-size: 17px;
  line-height: 1.5;
  min-height: 100%;
  -webkit-font-smoothing: antialiased;
}
img { max-width: 100%; }
[hidden] { display: none !important; }
a { color: var(--cyan); text-decoration-thickness: 1px; text-underline-offset: 3px; }
a:hover { color: var(--cyan-2); }
:focus-visible {
  outline: 2px solid var(--focus);
  outline-offset: 3px;
}
.skip {
  position: absolute; left: 12px; top: 8px; z-index: 20;
  background: var(--cyan); color: var(--ink); font-weight: 600;
  padding: 8px 12px; border-radius: 8px; text-decoration: none;
  transform: translateY(-120%);
}
.skip:focus { transform: none; color: var(--ink); }

/* Backdrop: radial glow + CSS grid, perspective floor handled in hero */
.page-bg {
  position: fixed; inset: 0; z-index: -2; pointer-events: none;
  background:
    radial-gradient(1200px 600px at 70% -10%, rgba(40, 120, 160, 0.22), transparent 60%),
    radial-gradient(800px 500px at 10% 100%, rgba(20, 80, 110, 0.18), transparent 55%),
    var(--bg);
}
.page-bg::after {
  content: "";
  position: absolute; inset: 0;
  background-image:
    linear-gradient(rgba(80, 210, 240, 0.045) 1px, transparent 1px),
    linear-gradient(90deg, rgba(80, 210, 240, 0.045) 1px, transparent 1px);
  background-size: 48px 48px;
  mask-image: radial-gradient(ellipse at 50% 0%, #000 20%, transparent 80%);
  opacity: 0.9;
}

.wrap {
  max-width: 1180px;
  margin: 0 auto;
  padding: 28px max(20px, env(safe-area-inset-left)) 64px max(20px, env(safe-area-inset-right));
}

/* Top nav */
.topnav {
  position: sticky; top: 0; z-index: 10;
  backdrop-filter: blur(16px);
  background: rgba(5, 8, 12, 0.78);
  border-bottom: 1px solid var(--line);
}
.topnav .inner {
  max-width: 1180px; margin: 0 auto;
  display: flex; align-items: center; gap: 18px; flex-wrap: wrap;
  padding: 10px max(20px, env(safe-area-inset-left));
}
.brand {
  display: flex; align-items: center; gap: 10px;
  color: var(--fg); text-decoration: none; font-family: var(--display);
  font-weight: 700; font-size: 20px; letter-spacing: 0.04em;
}
.brand svg { display: block; }
.brand:hover { color: var(--cyan-2); }
.nav-links {
  display: flex; flex-wrap: wrap; gap: 4px 2px; margin-left: auto;
  list-style: none; padding: 0;
}
.nav-links a {
  color: var(--muted); text-decoration: none; font-size: 14px; font-weight: 500;
  padding: 7px 10px; border-radius: 999px;
}
.nav-links a:hover, .nav-links a[aria-current="page"] {
  color: var(--fg); background: var(--cyan-dim);
}
.nav-links a[aria-current="page"] { color: var(--cyan); }

/* Hero */
.hero {
  position: relative;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: 28px;
  background: linear-gradient(180deg, rgba(8, 20, 32, 0.5), rgba(5, 10, 16, 0.85));
  margin: 28px 0 12px;
  min-height: 280px;
}
.hero-art {
  position: absolute; inset: 0; z-index: 0; pointer-events: none;
  color: var(--cyan);
}
.hero-art svg { width: 100%; height: 100%; display: block; }
.hero-copy {
  position: relative; z-index: 1;
  padding: 48px 32px 40px;
  max-width: 42rem;
}
.eyebrow {
  display: block;
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--cyan);
  font-weight: 500;
  margin-bottom: 8px;
}
h1 {
  font-family: var(--display);
  font-weight: 700;
  font-size: clamp(36px, 6vw, 64px);
  line-height: 0.95;
  letter-spacing: 0.02em;
  margin: 0 0 12px;
  text-wrap: balance;
}
.lede {
  color: var(--muted);
  font-size: 18px;
  line-height: 1.45;
  margin: 0 0 8px;
  max-width: 58ch;
}
.checked { margin: 8px 0 0; color: var(--muted); font-size: 14px; }

/* Section cards on the home page */
.grp { margin-top: 48px; }
.grp h2 {
  font-family: var(--display);
  font-weight: 650;
  font-size: clamp(24px, 3vw, 32px);
  letter-spacing: 0.04em;
  margin: 0 0 16px;
}
.grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 16px;
}
.card, .pcard {
  display: flex; flex-direction: column; gap: 8px;
  padding: 22px 22px 20px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  box-shadow: 0 0 0 1px rgba(61, 232, 255, 0.04), 0 12px 40px rgba(0, 0, 0, 0.35);
  backdrop-filter: blur(12px);
  color: inherit;
  text-decoration: none;
  transition: border-color .2s, box-shadow .2s, transform .2s;
}
a.card:hover, a.card:focus-visible,
.pcard:hover, .pcard:focus-within {
  border-color: var(--cyan);
  box-shadow: 0 0 0 1px var(--cyan), 0 0 28px var(--cyan-glow), 0 16px 40px rgba(0, 0, 0, 0.45);
  transform: translateY(-2px);
  color: inherit;
}
.cnt {
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--cyan);
  font-weight: 500;
}
.nm {
  font-family: var(--display);
  font-weight: 700;
  font-size: 26px;
  line-height: 1.05;
  letter-spacing: 0.02em;
}
.ds { color: var(--muted); font-size: 15px; flex: 1; }
.go { font-weight: 600; font-size: 14px; color: var(--cyan); margin-top: 6px; }

/* Filters / search / sort */
.toolbar {
  display: flex; flex-wrap: wrap; gap: 12px 16px;
  align-items: center;
  margin: 22px 0 10px;
}
.chips { display: flex; flex-wrap: wrap; gap: 8px; }
.chip {
  font: 500 13px var(--body);
  padding: 7px 13px;
  border-radius: 999px;
  border: 1px solid var(--line);
  background: var(--btn);
  color: var(--fg);
  cursor: pointer;
}
.chip:hover { background: var(--btn-h); }
.chip[aria-pressed="true"] {
  background: var(--cyan);
  color: var(--ink);
  border-color: var(--cyan);
  font-weight: 600;
}
.search, .sort {
  display: flex; flex-direction: column; gap: 4px;
  font-size: 12px; color: var(--muted); font-family: var(--mono);
  letter-spacing: 0.06em; text-transform: uppercase;
}
.search input, .sort select {
  font: 500 15px var(--body);
  letter-spacing: 0;
  text-transform: none;
  color: var(--fg);
  background: var(--surface-2);
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 8px 12px;
  min-width: 220px;
}
.sort select { min-width: 180px; }
.count { color: var(--muted); font-size: 14px; margin: 0 0 14px; }

/* Product cards */
.pcards {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 16px;
}
.pcard { gap: 10px; color: var(--fg); }
.pcard .maker {
  display: block;
  font-size: 13px;
  color: var(--muted);
  font-weight: 500;
  margin-top: 2px;
}
.known { margin: 0; font-size: 15px; color: var(--fg); }
.tags { display: flex; flex-wrap: wrap; gap: 6px; }
.tag {
  font-size: 11px; font-weight: 600;
  padding: 3px 8px; border-radius: 999px;
  background: var(--cyan-dim); color: var(--cyan-2);
  border: 1px solid rgba(61, 232, 255, 0.2);
}
.price, .learn, .sub {
  display: block;
  font-size: 13px;
  color: var(--muted);
}
.price b, .learn b { color: var(--fg); font-weight: 600; }
.stars { color: var(--cyan); font-size: 18px; letter-spacing: 1px; line-height: 1; }
.stars.off { color: rgba(80, 210, 240, 0.22); }
.starline { white-space: nowrap; }
.pop-row { display: grid; gap: 2px; }
.pc { display: grid; gap: 4px; font-size: 14px; margin-top: 4px; }
.pro { color: var(--pro); font-weight: 600; }
.con { color: var(--con); }
.official {
  margin-top: 6px;
  font-weight: 600;
  font-size: 14px;
  color: var(--cyan);
  text-decoration: none;
}
.official:hover { text-decoration: underline; }

/* Notes */
.notes {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 16px;
  margin-top: 36px;
}
.notes section {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  padding: 20px 22px;
}
.notes h2 {
  font-family: var(--display);
  font-size: 22px;
  margin: 0 0 8px;
  letter-spacing: 0.03em;
}
.notes p, .notes li { color: var(--muted); font-size: 14.5px; margin: 0; }
.notes ul { margin: 0; padding-left: 18px; display: grid; gap: 6px; }

/* Footer */
.site-footer {
  max-width: 1180px;
  margin: 8px auto 40px;
  padding: 0 max(20px, env(safe-area-inset-left)) 24px;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.55;
}
.site-footer p { margin: 0 0 10px; }
.kofi { text-align: center; }

/* Updates / article pages */
article.wrap h2 { font-family: var(--display); letter-spacing: 0.03em; }
article.wrap time { color: var(--cyan); font-family: var(--mono); font-size: 13px; }
.log { border-left: 2px solid var(--line); padding-left: 16px; margin: 24px 0; }
.log h3 { margin: 0 0 6px; font-size: 20px; font-family: var(--display); }

.back {
  display: inline-block;
  margin: 16px 0 0 max(20px, env(safe-area-inset-left));
  font-weight: 600;
  font-size: 14px;
  text-decoration: none;
}

@media (max-width: 640px) {
  .hero-copy { padding: 32px 20px 28px; }
  .nav-links { margin-left: 0; width: 100%; }
  .search input { min-width: 0; width: 100%; }
  .toolbar { flex-direction: column; align-items: stretch; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  a.card, a.pcard, a.card:hover { transition: none; transform: none; }
}