:root {
  --bg: #0e0e10;
  --mono: 'IBM Plex Mono', ui-monospace, monospace;
  --sans: 'Instrument Sans', system-ui, sans-serif;
  --nav-h: 2.5rem;
  --step: 2rem;
  --scroll-tick: 28vh;
  --overlap: 24vh;
}

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

body {
  font-family: var(--sans);
  background: var(--bg);
  color: #e8e6e3;
  line-height: 1.5;
}

.nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 200;
  display: flex;
  align-items: center;
  gap: 1rem;
  padding: 0.55rem 1rem;
  font-family: var(--mono);
  font-size: 0.62rem;
  background: rgba(14, 14, 16, 0.92);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid rgba(255,255,255,0.05);
}

.nav a { color: #6b6966; text-decoration: none; }
.nav a:hover { color: #c4a574; }
.variants { margin-left: auto; color: #4a4844; }
.variants a { color: #5a5854; }
.depth { color: #c4a574; font-weight: 600; }

.stack-mount {
  max-width: 500px;
  margin: 0 auto;
  padding: var(--nav-h) 1rem 0;
}

.scroll-section {
  height: var(--scroll-tick);
  position: relative;
}

.scroll-section--final {
  height: 18vh;
  min-height: 200px;
}

.stack-stop { height: 1px; margin-bottom: 3rem; }

.layer {
  position: sticky;
  margin: 0 0.35rem calc(-1 * var(--overlap)) 0.35rem;
  border-radius: 8px 8px 6px 6px;
  border: 1px solid rgba(255,255,255,0.08);
  box-shadow: 0 10px 32px rgba(0,0,0,0.45);
}

.layer-tab {
  position: absolute;
  top: -6px;
  left: 10px;
  right: 10px;
  height: 6px;
  border-radius: 5px 5px 0 0;
  background: inherit;
  filter: brightness(1.12);
  border: 1px solid rgba(255,255,255,0.07);
  border-bottom: none;
}

.layer-0 { z-index: 1; background: #1c1c20; top: calc(var(--nav-h) + 0.5rem); }
.layer-1 { z-index: 2; background: #24242c; top: calc(var(--nav-h) + 0.5rem + var(--step)); }
.layer-2 { z-index: 3; background: #2c2c36; top: calc(var(--nav-h) + 0.5rem + var(--step) * 2); }
.layer-3 { z-index: 4; background: #343440; top: calc(var(--nav-h) + 0.5rem + var(--step) * 3); }
.layer-4 { z-index: 5; background: #3c3c4a; top: calc(var(--nav-h) + 0.5rem + var(--step) * 4); }
.layer-5 { z-index: 6; background: #444454; top: calc(var(--nav-h) + 0.5rem + var(--step) * 5); }
.layer-6 {
  z-index: 7;
  background: #4c4c5e;
  top: calc(var(--nav-h) + 0.5rem + var(--step) * 6);
  margin-bottom: 0;
}

.layer-inner { padding: 1.1rem 1.25rem 1.2rem; }
.layer-head {
  display: flex; flex-wrap: wrap; align-items: center; gap: 0.35rem 0.65rem;
  margin-bottom: 0.6rem; padding-bottom: 0.45rem;
  border-bottom: 1px solid rgba(255,255,255,0.06);
  font-family: var(--mono); font-size: 0.6rem;
}
.layer-id { color: #c4a574; font-weight: 600; }
.layer-name { color: #6b6966; text-transform: uppercase; letter-spacing: 0.1em; }
.layer-link { margin-left: auto; color: #8b9cb3; text-decoration: none; font-size: 0.58rem; }
.layer-link:hover { color: #c4a574; }
.layer h1 { font-size: 2rem; font-weight: 600; letter-spacing: -0.03em; line-height: 1.1; }
.layer h2 { font-size: 1.15rem; font-weight: 600; margin-bottom: 0.3rem; }
.tagline { font-family: var(--mono); font-size: 0.65rem; color: #6b6966; margin-bottom: 0.4rem; }
.body { font-size: 0.88rem; color: #a8a6a1; margin-bottom: 0.5rem; }
.chips { display: flex; flex-wrap: wrap; gap: 0.3rem; margin-bottom: 0.4rem; }
.chips span {
  font-family: var(--mono); font-size: 0.55rem; padding: 0.15rem 0.4rem;
  background: rgba(196,165,116,0.1); color: #c4a574;
  border: 1px solid rgba(196,165,116,0.2); border-radius: 3px;
}
.avail { font-family: var(--mono); font-size: 0.62rem; color: #7eb87a; }
.contact-row { display: flex; flex-wrap: wrap; gap: 0.45rem; margin: 0.65rem 0 0.4rem; }
.btn {
  font-family: var(--mono); font-size: 0.68rem; padding: 0.45rem 0.75rem;
  background: #c4a574; color: #0e0e10; text-decoration: none; font-weight: 600; border-radius: 4px;
}
.btn-ghost { background: transparent; color: #c4a574; border: 1px solid rgba(196,165,116,0.35); }
.guarantees { font-family: var(--mono); font-size: 0.58rem; color: #5a5854; }
.site-foot {
  display: flex; justify-content: space-between; max-width: 500px; margin: 0 auto;
  padding: 0 1.5rem 2.5rem; font-family: var(--mono); font-size: 0.6rem; color: #4a4844;
}
.site-foot a { color: #4a4844; text-decoration: none; }
.stack-ruler {
  position: fixed; right: 0.75rem; top: 50%; transform: translateY(-50%);
  z-index: 50; display: flex; flex-direction: column; gap: 0.15rem;
  font-family: var(--mono); font-size: 0.48rem; color: #2a2a30; pointer-events: none;
}
.stack-ruler span.active { color: #c4a574; }

@media (max-width: 700px) {
  .stack-ruler, .variants { display: none; }
  :root { --scroll-tick: 26vh; --overlap: 22vh; --step: 1.65rem; }
}