:root {
  --nav: 2.5rem;
  --stick: 0.5rem;
  --step: 1.85rem;
  --tab-h: 1.65rem;
  --scroll-tick: 26vh;
  --overlap: 22vh;
  --mono: 'IBM Plex Mono', monospace;
  --sans: 'Instrument Sans', system-ui, sans-serif;
}

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

body { font-family: var(--sans); background: #2a2824; color: #1a1814; }

.nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 300;
  display: flex; gap: 1rem; padding: 0.5rem 1rem;
  font-family: var(--mono); font-size: 0.62rem;
  background: rgba(42,40,36,0.95); color: #c4b8a8;
}

.nav a { color: #8a8278; text-decoration: none; }
.depth { margin-left: auto; color: #d4a574; font-weight: 600; }

.mount {
  max-width: 520px;
  margin: 0 auto;
  padding: calc(var(--nav) + 0.5rem) 1rem 0;
}

.scroll-section { height: var(--scroll-tick); position: relative; }
.scroll-section--final { height: 16vh; min-height: 180px; }
.stop { height: 1px; margin-bottom: 3rem; }

/* Folder stacks; tab sits above body and stays visible */
.folder {
  position: sticky;
  margin-bottom: calc(-1 * var(--overlap));
  padding-top: 0;
}

.tab {
  position: relative;
  z-index: 50;
  display: inline-block;
  font-family: var(--mono);
  font-size: 0.58rem;
  font-weight: 600;
  letter-spacing: 0.05em;
  padding: 0.35rem 0.85rem 0.3rem;
  border-radius: 6px 6px 0 0;
  border: 1px solid rgba(0,0,0,0.12);
  border-bottom: none;
  margin-left: 0.5rem;
  box-shadow: 0 -2px 8px rgba(0,0,0,0.12);
}

.body {
  position: relative;
  z-index: 1;
  background: #e8e2d4;
  border: 1px solid #c4b8a8;
  border-radius: 0 8px 8px 8px;
  padding: 1rem 1.2rem 1.1rem;
  box-shadow: 3px 6px 20px rgba(0,0,0,0.2);
  min-height: 100px;
}

.f0 { top: calc(var(--nav) + var(--stick)); z-index: 1; }
.f0 .tab { background: #c9a86c; color: #2a2824; z-index: 107; }
.f1 { top: calc(var(--nav) + var(--stick) + var(--step)); z-index: 2; }
.f1 .tab { background: #a8c4d4; color: #1a2830; z-index: 108; }
.f2 { top: calc(var(--nav) + var(--stick) + var(--step) * 2); z-index: 3; }
.f2 .tab { background: #b8d4a8; color: #1a2818; z-index: 109; }
.f3 { top: calc(var(--nav) + var(--stick) + var(--step) * 3); z-index: 4; }
.f3 .tab { background: #d4b8c4; color: #2a1820; z-index: 110; }
.f4 { top: calc(var(--nav) + var(--stick) + var(--step) * 4); z-index: 5; }
.f4 .tab { background: #d4c8a8; color: #2a2418; z-index: 111; }
.f5 { top: calc(var(--nav) + var(--stick) + var(--step) * 5); z-index: 6; }
.f5 .tab { background: #c4c4c4; color: #2a2a2a; z-index: 112; }
.f6 {
  top: calc(var(--nav) + var(--stick) + var(--step) * 6);
  z-index: 7;
  margin-bottom: 0;
}
.f6 .tab { background: #2a4a6b; color: #e8e2d4; z-index: 113; }

.body h1, .body h2 { font-size: 1.15rem; margin-bottom: 0.3rem; }
.body p { font-size: 0.86rem; color: #4a4844; }
.body a { color: #2a4a6b; }
.avail { font-family: var(--mono); font-size: 0.62rem; color: #3d6b3d; margin-top: 0.3rem; }
.btn {
  font-family: var(--mono); font-size: 0.65rem; padding: 0.35rem 0.65rem;
  background: #2a4a6b; color: #fff; text-decoration: none; border-radius: 3px; margin-right: 0.3rem;
}
.btn.ghost { background: transparent; color: #2a4a6b; border: 1px solid #2a4a6b; }

.foot {
  display: flex; justify-content: space-between; max-width: 520px; margin: 0 auto;
  padding: 0 1rem 2rem; font-family: var(--mono); font-size: 0.6rem; color: #6a6458;
}
.foot a { color: #6a6458; text-decoration: none; }

@media (max-width: 700px) {
  :root { --step: 1.5rem; --overlap: 20vh; --scroll-tick: 24vh; }
}