@import '../shared/stack-vars.css';

:root {
  --tab-offset: 2.4rem;
  --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: 400;
  display: flex; flex-wrap: wrap; gap: 0.5rem 1rem; padding: 0.5rem 1rem;
  font-family: var(--mono); font-size: 0.62rem;
  background: rgba(42,40,36,0.97); color: #c4b8a8;
}

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

/* Quick-jump rail */
.tab-rail {
  position: fixed;
  top: 2.5rem;
  right: max(0.5rem, calc(50% - 360px));
  z-index: 350;
  display: flex;
  flex-direction: column;
  gap: 0.2rem;
  padding: 0.35rem;
  background: rgba(42,40,36,0.9);
  border: 1px solid #4a4844;
  border-radius: 6px;
}

.rail-tab {
  font-family: var(--mono);
  font-size: 0.55rem;
  padding: 0.2rem 0.45rem;
  border: none;
  border-radius: 3px;
  background: transparent;
  color: #8a8278;
  cursor: pointer;
  text-align: left;
}

.rail-tab:hover,
.rail-tab.active {
  background: #c9a86c;
  color: #2a2824;
}

.mount {
  width: min(640px, 100%);
  margin: 0 auto;
  padding: calc(var(--stack-nav) + 0.25rem) 1rem 0;
}

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

.scroll-section--final {
  height: 12vh;
  min-height: 220px;
}

.stack-stop { height: 1px; margin-bottom: 4rem; }

.folder {
  position: sticky;
  width: 100%;
  margin-bottom: calc(-1 * var(--stack-overlap));
}

/* Tab: sticky with layer, offset left so all labels readable when stacked */
.tab {
  position: sticky;
  display: block;
  width: fit-content;
  max-width: calc(100% - 1rem);
  font-family: var(--mono);
  font-size: 0.62rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  padding: 0.4rem 1rem 0.35rem;
  border: 1px solid rgba(0,0,0,0.15);
  border-bottom: none;
  border-radius: 8px 8px 0 0;
  cursor: pointer;
  text-align: left;
  z-index: 50;
  box-shadow: 0 -3px 10px rgba(0,0,0,0.15);
  transition: filter 0.15s, transform 0.15s;
}

.tab:hover { filter: brightness(1.08); transform: translateY(-1px); }

.body {
  background: #e8e2d4;
  border: 1px solid #c4b8a8;
  border-radius: 0 10px 10px 10px;
  padding: 1.25rem 1.4rem 1.35rem;
  min-height: 200px;
  box-shadow: 0 8px 28px rgba(0,0,0,0.22);
  position: relative;
  z-index: 1;
}

.f0 { top: calc(var(--stack-nav) + var(--stack-stick)); z-index: 1; }
.f0 .tab { top: calc(var(--stack-nav) + var(--stack-stick)); margin-left: calc(var(--tab-offset) * 0); z-index: 170; background: #c9a86c; color: #2a2824; }

.f1 { top: calc(var(--stack-nav) + var(--stack-stick) + var(--stack-step)); z-index: 2; }
.f1 .tab { top: calc(var(--stack-nav) + var(--stack-stick) + var(--stack-step)); margin-left: calc(var(--tab-offset) * 1); z-index: 171; background: #a8c4d4; color: #1a2830; }

.f2 { top: calc(var(--stack-nav) + var(--stack-stick) + var(--stack-step) * 2); z-index: 3; }
.f2 .tab { top: calc(var(--stack-nav) + var(--stack-stick) + var(--stack-step) * 2); margin-left: calc(var(--tab-offset) * 2); z-index: 172; background: #b8d4a8; color: #1a2818; }

.f3 { top: calc(var(--stack-nav) + var(--stack-stick) + var(--stack-step) * 3); z-index: 4; }
.f3 .tab { top: calc(var(--stack-nav) + var(--stack-stick) + var(--stack-step) * 3); margin-left: calc(var(--tab-offset) * 3); z-index: 173; background: #d4b8c4; color: #2a1820; }

.f4 { top: calc(var(--stack-nav) + var(--stack-stick) + var(--stack-step) * 4); z-index: 5; }
.f4 .tab { top: calc(var(--stack-nav) + var(--stack-stick) + var(--stack-step) * 4); margin-left: calc(var(--tab-offset) * 4); z-index: 174; background: #d4c8a8; color: #2a2418; }

.f5 { top: calc(var(--stack-nav) + var(--stack-stick) + var(--stack-step) * 5); z-index: 6; }
.f5 .tab { top: calc(var(--stack-nav) + var(--stack-stick) + var(--stack-step) * 5); margin-left: calc(var(--tab-offset) * 5); z-index: 175; background: #c4c4c4; color: #2a2a2a; }

.f6 {
  top: calc(var(--stack-nav) + var(--stack-stick) + var(--stack-step) * 6);
  z-index: 7;
  margin-bottom: 0;
}
.f6 .tab { top: calc(var(--stack-nav) + var(--stack-stick) + var(--stack-step) * 6); margin-left: calc(var(--tab-offset) * 6); z-index: 176; background: #2a4a6b; color: #e8e2d4; }

.body h1 { font-size: 1.65rem; margin-bottom: 0.35rem; }
.body h2 { font-size: 1.25rem; margin-bottom: 0.4rem; }
.body p { font-size: 0.92rem; color: #4a4844; line-height: 1.5; }
.body a { color: #2a4a6b; }
.avail { font-family: var(--mono); font-size: 0.68rem; color: #3d6b3d; margin-top: 0.5rem; }
.btn {
  font-family: var(--mono); font-size: 0.7rem; padding: 0.45rem 0.75rem;
  background: #2a4a6b; color: #fff; text-decoration: none; border-radius: 4px; margin-right: 0.4rem; display: inline-block; margin-top: 0.35rem;
}
.btn.ghost { background: transparent; color: #2a4a6b; border: 1px solid #2a4a6b; }

.foot {
  display: flex; justify-content: space-between;
  width: min(640px, 100%); margin: 0 auto;
  padding: 0 1rem 2rem; font-family: var(--mono); font-size: 0.62rem; color: #6a6458;
}
.foot a { color: #6a6458; text-decoration: none; }

@media (max-width: 720px) {
  .tab-rail { display: none; }
  :root { --tab-offset: 1.5rem; --stack-tick: 12vh; --stack-overlap: 10.5vh; }
  .f6 .tab { margin-left: calc(var(--tab-offset) * 3); }
}