/* ==========================================================================
   BUSAC — main stylesheet
   Uses tokens from tokens.css only. Sections:
   1 base · 2 typography · 3 layout · 4 nav · 5 footer · 6 buttons/links
   7 shared components · 8 page-specific · 9 motion · 10 responsive
   ========================================================================== */

/* ---------- 1. Base ---------- */
*,
*::before,
*::after { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--font-sans);
  font-size: var(--fs-body);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

img, svg, video { max-width: 100%; display: block; }

.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  background: var(--ink);
  color: var(--paper);
  padding: 10px 18px;
  z-index: 999;
}
.skip-link:focus { left: 12px; top: 12px; }

:focus-visible {
  outline: 2px solid var(--blue);
  outline-offset: 3px;
}
.surface-dark :focus-visible,
.section--dark :focus-visible { outline-color: var(--blue-soft); }

/* ---------- 2. Typography ---------- */
h1, h2, h3, h4 { margin: 0 0 0.5em; font-weight: 500; line-height: 1.12; }

.display,
h1.display, h2.display {
  font-family: var(--font-display);
  font-weight: 400;
  letter-spacing: -0.01em;
}

.display em, .display i {
  font-style: italic;
  font-weight: 400;
}

.hero-title { font-size: var(--fs-hero); }
.h1 { font-size: var(--fs-h1); }
.h2 { font-size: var(--fs-h2); }
.h3 { font-size: var(--fs-h3); font-family: var(--font-sans); font-weight: 600; }

.lead {
  font-size: var(--fs-lead);
  line-height: 1.6;
  color: var(--muted);
  max-width: 46em;
}

.mono {
  font-family: var(--font-mono);
  font-size: var(--fs-small);
  letter-spacing: 0.02em;
}

.eyebrow {
  font-family: var(--font-mono);
  font-size: var(--fs-eyebrow);
  font-weight: 500;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--accent);
  margin: 0 0 1.4rem;
}

.muted { color: var(--muted); }

p { margin: 0 0 1em; }
p:last-child { margin-bottom: 0; }

.maxw { max-width: 62em; }
.maxw-narrow { max-width: 44em; }

/* ---------- 3. Layout ---------- */
.container {
  max-width: var(--container);
  margin: 0 auto;
  padding-left: var(--gutter);
  padding-right: var(--gutter);
}

.section {
  padding-top: var(--space-section);
  padding-bottom: var(--space-section);
  background: var(--bg);
  color: var(--fg);
}
.section--sm {
  padding-top: var(--space-section-sm);
  padding-bottom: var(--space-section-sm);
}
.section--dark { background: var(--ink); }
.section--dark-2 { background: var(--ink-2); }

.rule {
  border: 0;
  border-top: var(--rule);
  margin: var(--space-block) 0;
}
.section--dark .rule, .surface-dark .rule { border-top: var(--rule-dark); }

.grid {
  display: grid;
  gap: clamp(20px, 3vw, 44px);
}
.grid--2 { grid-template-columns: repeat(2, 1fr); }
.grid--3 { grid-template-columns: repeat(3, 1fr); }
.grid--4 { grid-template-columns: repeat(4, 1fr); }

.section-head { margin-bottom: var(--space-block); }
.section-head .h2 { max-width: 20em; }

/* ---------- 4. Navigation ---------- */
.nav {
  position: sticky;
  top: 0;
  z-index: var(--z-nav);
  background: transparent;
  transition: background var(--dur-micro) var(--ease), box-shadow var(--dur-micro) var(--ease);
}
.nav.is-scrolled {
  background: rgba(11, 21, 32, 0.6);
  backdrop-filter: blur(16px) saturate(1.1);
  -webkit-backdrop-filter: blur(16px) saturate(1.1);
}
.nav.is-open { background: var(--ink); }
.nav__inner { position: relative; z-index: 2; }
body.nav-light .nav:not(.is-scrolled):not(.is-open) {
  /* pages that start on a light hero get an ink nav immediately */
  background: var(--ink);
}
.nav, .nav a { color: var(--paper); }

.nav__inner {
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 var(--gutter);
  height: var(--nav-height);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.nav__brand {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  flex-shrink: 0;
}
.nav__mark { width: 30px; height: 30px; fill: var(--paper); }
.nav__wordmark {
  font-family: var(--font-display);
  font-size: 1.28rem;
  letter-spacing: 0.34em;
  margin-right: -0.34em; /* optical: cancel trailing tracking */
  transform: translateY(1px);
}

.nav__links {
  display: flex;
  align-items: center;
  gap: clamp(16px, 2.2vw, 34px);
  white-space: nowrap;
}
.nav__links a {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  font-weight: 500;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  text-decoration: none;
  opacity: 0.82;
  padding: 6px 0;
  border-bottom: 1px solid transparent;
  transition: opacity var(--dur-micro) var(--ease), border-color var(--dur-micro) var(--ease);
}
.nav__links a:hover { opacity: 1; }
.nav__links a.is-active {
  opacity: 1;
  border-bottom-color: var(--blue-soft);
}
.nav__cta { opacity: 1 !important; }
.nav__cta:hover span { transform: translateX(3px); }
.nav__cta span { display: inline-block; transition: transform var(--dur-micro) var(--ease); }

.nav__toggle {
  display: none;
  background: none;
  border: 0;
  padding: 10px;
  cursor: pointer;
}
.nav__toggle-line {
  display: block;
  width: 26px;
  height: 2px;
  background: var(--paper);
  margin: 6px 0;
  transition: transform var(--dur-micro) var(--ease), opacity var(--dur-micro) var(--ease);
}
.nav__toggle[aria-expanded="true"] .nav__toggle-line:first-child { transform: translateY(4px) rotate(45deg); }
.nav__toggle[aria-expanded="true"] .nav__toggle-line:last-child { transform: translateY(-4px) rotate(-45deg); }

.mobile-menu {
  position: fixed;
  inset: 0;
  width: 100%;
  height: 100dvh;
  background: var(--ink);
  z-index: var(--z-menu); /* above everything; the overlay carries its own close bar */
  padding: 0 var(--gutter) 56px;
  overflow-y: auto; /* the whole overlay scrolls; no nested scroll container */
  -webkit-overflow-scrolling: touch;
  opacity: 0;
  visibility: hidden;
  transform: translateY(10px);
  transition: opacity var(--dur-micro) var(--ease),
              transform var(--dur-micro) var(--ease),
              visibility 0s linear var(--dur-micro);
}
.mobile-menu.is-open {
  opacity: 1;
  visibility: visible;
  transform: none;
  transition-delay: 0s;
}

/* Close bar inside the overlay: closing never depends on stacking above it */
.mobile-menu__bar {
  height: var(--nav-height);
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 3vh;
}
.mobile-menu__close {
  position: relative;
  width: 46px;
  height: 46px;
  background: none;
  border: 0;
  cursor: pointer;
  padding: 0;
}
.mobile-menu__close span {
  position: absolute;
  left: 10px;
  top: 22px;
  width: 26px;
  height: 2px;
  background: var(--paper);
}
.mobile-menu__close span:first-child { transform: rotate(45deg); }
.mobile-menu__close span:last-child { transform: rotate(-45deg); }

/* Main items */
.mobile-menu nav { display: flex; flex-direction: column; }
.m-link,
.m-item__head {
  font-family: var(--font-display);
  font-size: clamp(1.6rem, 6vw, 2.2rem);
  color: var(--paper);
  text-decoration: none;
  padding: 16px 0;
  border-bottom: 1px solid var(--line-on-dark);
  background: none;
  border-left: 0; border-right: 0; border-top: 0;
  text-align: left;
  cursor: pointer;
  width: 100%;
}
.m-item__head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}
.m-item__chev {
  font-size: 1.1rem;
  color: var(--muted-on-dark);
  transform: translateY(-4px);
  transition: transform var(--dur-micro) var(--ease), color var(--dur-micro) var(--ease);
}
.m-item.is-open .m-item__chev { transform: translateY(2px) rotate(180deg); color: var(--blue-soft); }
.m-item.is-open .m-item__head { border-bottom-color: transparent; }

/* Subs: collapsed by default (accordion) */
.m-item__subs {
  display: none;
  flex-direction: column;
  padding: 0 0 18px 18px;
  border-bottom: 1px solid var(--line-on-dark);
}
.m-item.is-open .m-item__subs { display: flex; }
.m-item__subs a {
  font-family: var(--font-sans);
  font-size: 1rem;
  color: var(--muted-on-dark);
  text-decoration: none;
  padding: 10px 0;
}
.m-item__subs a:active { color: var(--paper); }
.m-item__view {
  font-family: var(--font-mono) !important;
  font-size: 0.74rem !important;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--blue-soft) !important;
}

@media (min-width: 1081px) { .mobile-menu { display: none; } }
.mobile-menu nav { display: flex; flex-direction: column; gap: 4px; }
.mobile-menu a {
  font-family: var(--font-display);
  font-size: clamp(1.7rem, 6vw, 2.4rem);
  color: var(--paper);
  text-decoration: none;
  padding: 10px 0;
  border-bottom: 1px solid var(--line-on-dark);
}
.mobile-menu__cta { color: var(--blue-soft) !important; border-bottom: 0 !important; margin-top: 14px; }

/* ---------- 5. Footer ---------- */
.footer {
  background: var(--ink);
  color: var(--paper);
  padding: var(--space-section-sm) 0 40px;
}
.footer__inner {
  display: grid;
  grid-template-columns: 1.6fr repeat(4, 1fr);
  gap: clamp(28px, 4vw, 56px);
  padding-bottom: var(--space-block);
  border-bottom: var(--rule-dark);
}
.footer__mark { width: 34px; height: 34px; fill: var(--paper); margin-bottom: 14px; }
.footer__name {
  font-family: var(--font-display);
  font-size: 1.3rem;
  letter-spacing: 0.3em;
  margin: 0 0 10px;
}
.footer__desc { color: var(--muted-on-dark); font-size: var(--fs-small); max-width: 26em; }
.footer__motto { color: var(--blue-soft); margin-top: 14px; letter-spacing: 0.18em; font-size: 0.72rem; }

.footer__col { display: flex; flex-direction: column; gap: 9px; }
.footer__head {
  color: var(--muted-on-dark);
  text-transform: uppercase;
  letter-spacing: 0.2em;
  font-size: 0.68rem;
  margin: 0 0 6px;
}
.footer__col a {
  color: var(--paper);
  opacity: 0.8;
  text-decoration: none;
  font-size: var(--fs-small);
  transition: opacity var(--dur-micro) var(--ease);
}
.footer__col a:hover { opacity: 1; }

.footer__legal {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
  padding-top: 26px;
  color: var(--muted-on-dark);
  font-size: 0.8rem;
}
.footer__legal p { margin: 0; }

/* ---------- 6. Buttons & text links ----------
   Every button shows its label at rest. No hover-revealed text. */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  font-weight: 500;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  text-decoration: none;
  padding: 15px 26px;
  border-radius: var(--radius);
  border: 1px solid transparent;
  cursor: pointer;
  transition: background var(--dur-micro) var(--ease),
              color var(--dur-micro) var(--ease),
              border-color var(--dur-micro) var(--ease),
              transform var(--dur-micro) var(--ease);
}
.btn span[aria-hidden] { transition: transform var(--dur-micro) var(--ease); }
.btn:hover span[aria-hidden] { transform: translateX(4px); }

/* On dark surfaces */
.btn--primary-dark { background: var(--paper); color: var(--ink); }
.btn--primary-dark:hover { background: #fffdf6; }
.btn--secondary-dark {
  background: transparent;
  color: var(--paper);
  border-color: rgba(244, 242, 236, 0.4);
}
.btn--secondary-dark:hover { border-color: var(--paper); }

/* On light surfaces */
.btn--primary-light { background: var(--ink); color: var(--paper); }
.btn--primary-light:hover { background: var(--ink-2); }
.btn--secondary-light {
  background: transparent;
  color: var(--ink);
  border-color: rgba(11, 21, 32, 0.35);
}
.btn--secondary-light:hover { border-color: var(--ink); }

.textlink {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 0.76rem;
  font-weight: 500;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  text-decoration: none;
  color: var(--accent);
  border-bottom: 1px solid currentColor;
  padding-bottom: 3px;
  transition: opacity var(--dur-micro) var(--ease);
}
.textlink:hover { opacity: 0.75; }
.textlink span[aria-hidden] { display: inline-block; transition: transform var(--dur-micro) var(--ease); }
.textlink:hover span[aria-hidden] { transform: translateX(4px); }

.btn-row { display: flex; gap: 18px; flex-wrap: wrap; align-items: center; }

/* ---------- 7. Shared components ---------- */

/* Hero (dark, with moving media) */
.hero {
  position: relative;
  background: var(--ink);
  color: var(--paper);
  min-height: min(92vh, 900px);
  display: flex;
  align-items: center;
  overflow: hidden;
  margin-top: calc(-1 * var(--nav-height));
  padding-top: calc(var(--nav-height) + var(--space-section-sm));
  padding-bottom: var(--space-section-sm);
}
.hero--short { min-height: 0; padding-top: calc(var(--nav-height) + clamp(72px, 10vw, 140px)); }

.hero-media {
  position: absolute;
  inset: 0;
  z-index: 0;
}
.hero-media video,
.hero-media canvas {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
}
/* Hybrid hero -- three layers:
   1. footage (full-frame): cinematic ink-in-water, graded into midnight ink
   2. canvas: a whisper of woven light threads over the footage
   3. grade: keeps everything in the palette and the type readable */
.hero-media video {
  filter: saturate(0.25) contrast(1.05) brightness(0.6);
  mix-blend-mode: luminosity;
  opacity: 0.85;
}
.hero-media canvas { mix-blend-mode: screen; }
.hero-media::after {
  content: "";
  position: absolute;
  inset: 0;
  background:
    linear-gradient(180deg, rgba(11, 21, 32, 0.5) 0%, rgba(11, 21, 32, 0.18) 45%, rgba(11, 21, 32, 0.88) 100%),
    radial-gradient(90% 70% at 76% 30%, rgba(46, 98, 232, 0.12), transparent 65%);
}

.hero .container { position: relative; z-index: 1; }
.hero-title { max-width: 12em; }
.hero .lead { color: var(--muted-on-dark); }

/* Process line */
.process-line {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 18px;
  align-items: center;
  font-family: var(--font-mono);
  font-size: 0.76rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--muted);
}
.process-line .arrow { color: var(--accent); }
.process-line .final { color: var(--fg); }

/* Pillar cards */
.pillar {
  border-top: 1px solid var(--line);
  padding-top: 26px;
}
.pillar .pillar__num {
  font-family: var(--font-mono);
  font-size: 0.74rem;
  letter-spacing: 0.2em;
  color: var(--accent);
  display: block;
  margin-bottom: 14px;
}
.pillar h3 {
  font-family: var(--font-display);
  font-weight: 400;
  font-size: 1.5rem;
}
.pillar__sub { color: var(--muted); font-size: 0.95rem; margin-bottom: 0.8em; }
.pillar .tags {
  margin-top: 18px;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}
.tag {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.06em;
  padding: 5px 10px;
  border: 1px solid var(--line);
  color: var(--muted);
  border-radius: var(--radius);
}

/* Stat / metric */
.metric { border-top: 1px solid var(--line); padding-top: 18px; }
.metric__value {
  font-family: var(--font-display);
  font-size: clamp(2rem, 4vw, 3rem);
  line-height: 1;
  display: block;
  margin-bottom: 8px;
}
.metric__label { font-family: var(--font-mono); font-size: 0.74rem; letter-spacing: 0.12em; text-transform: uppercase; color: var(--muted); }
.metric__note { font-size: var(--fs-small); color: var(--muted); margin-top: 6px; }
.metric--verified .metric__value { color: var(--verified); }

/* Value Lab pipeline */
.pipeline {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 14px;
  align-items: center;
  font-family: var(--font-mono);
  font-size: 0.74rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
}
.pipeline .step {
  padding: 8px 14px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  color: var(--fg);
  background: transparent;
}
.pipeline .sep { color: var(--accent); }
.pipeline .gates { display: inline-flex; gap: 8px; }

/* Decision gates */
.gate {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  padding: 6px 12px;
  border-radius: var(--radius);
  border: 1px solid currentColor;
  background: transparent;
}
.section--dark .gate--scale, .surface-dark .gate--scale { color: var(--gate-scale); }
.section--dark .gate--modify, .surface-dark .gate--modify { color: var(--gate-modify); }
.section--dark .gate--stop, .surface-dark .gate--stop { color: var(--gate-stop); }
.gate--scale { color: var(--green); }
.gate--modify { color: var(--amber-light); }
.gate--stop { color: var(--stop-light); }

/* Stage cards (Value Lab worked example) */
.stage-card {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 22px;
  background: rgba(244, 242, 236, 0.02);
  display: flex;
  flex-direction: column;
}
.stage-card h3 { margin-bottom: 14px; }
/* Key-value rows: label left, value right, one line each */
.stage-card__kv {
  display: grid;
  grid-template-columns: auto 1fr;
  column-gap: 18px;
  row-gap: 9px;
  align-items: baseline;
  margin: 0;
}
.stage-card__kv dt {
  font-family: var(--font-mono);
  font-size: 0.66rem;
  font-weight: 500;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--muted);
  white-space: nowrap;
}
.stage-card__kv dd {
  margin: 0;
  font-size: 0.92rem;
  text-align: right;
  justify-self: end;
}
.stage-card__num {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--accent);
  display: block;
  margin-bottom: 10px;
}
.stage-card h3 { font-family: var(--font-display); font-weight: 400; font-size: 1.35rem; margin-bottom: 14px; }
.kv { display: grid; grid-template-columns: auto 1fr; gap: 5px 16px; font-size: 0.83rem; }
.kv dt { color: var(--muted); font-family: var(--font-mono); font-size: 0.72rem; letter-spacing: 0.04em; padding-top: 2px; }
.kv dd { margin: 0; text-align: right; }
.kv dd.verified { color: var(--verified); }

/* Value Evidence Record card */
.ver-card {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  max-width: 460px;
}
.ver-card__head {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
  padding: 14px 20px;
  border-bottom: 1px solid var(--line);
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}
.ver-card__body { padding: 18px 20px; }
.ver-card .kv { grid-template-columns: 1fr auto; }

/* Taxonomy cards */
.tax-card { border-top: 1px solid var(--line); padding-top: 20px; }
.tax-card__tier {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--accent);
  display: block;
  margin-bottom: 10px;
}
.tax-card--verified .tax-card__tier { color: var(--verified); }
.tax-card h3 { font-family: var(--font-display); font-weight: 400; font-size: 1.25rem; }

/* Data table */
.data-table { width: 100%; border-collapse: collapse; font-size: 0.9rem; }
.data-table caption {
  caption-side: top;
  text-align: left;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--muted);
  padding-bottom: 14px;
}
.data-table th, .data-table td { text-align: left; padding: 12px 16px 12px 0; border-bottom: 1px solid var(--line); }
.data-table th { font-family: var(--font-mono); font-size: 0.7rem; letter-spacing: 0.12em; text-transform: uppercase; color: var(--muted); font-weight: 500; }
.data-table td.num { font-family: var(--font-mono); font-size: 0.82rem; }

.table-scroll { overflow-x: auto; }

/* Quote */
.pullquote {
  font-family: var(--font-display);
  font-size: clamp(1.4rem, 3vw, 2.1rem);
  font-style: italic;
  line-height: 1.35;
  max-width: 26em;
  margin: 0;
}
.pullquote footer {
  font-family: var(--font-mono);
  font-style: normal;
  font-size: 0.72rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--muted);
  margin-top: 20px;
}

/* Chapter list (Playbook) */
.chapter-list { display: flex; flex-direction: column; }
.chapter-list a {
  display: grid;
  grid-template-columns: 70px 1fr auto;
  align-items: baseline;
  gap: 20px;
  padding: 22px 0;
  border-top: 1px solid var(--line);
  text-decoration: none;
  color: var(--fg);
  transition: opacity var(--dur-micro) var(--ease);
}
.chapter-list a:last-child { border-bottom: 1px solid var(--line); }
.chapter-list a:hover { opacity: 0.72; }
.chapter-list .num { font-family: var(--font-mono); font-size: 0.78rem; color: var(--accent); }
.chapter-list .name { font-family: var(--font-display); font-size: clamp(1.2rem, 2.4vw, 1.7rem); }
.chapter-list .desc { color: var(--muted); font-size: var(--fs-small); text-align: right; max-width: 22em; }

/* Insight rows */
.insight {
  display: block;
  padding: 30px 0;
  border-top: 1px solid var(--line);
  text-decoration: none;
  color: var(--fg);
  transition: opacity var(--dur-micro) var(--ease);
}
.insight:last-of-type { border-bottom: 1px solid var(--line); }
.insight:hover { opacity: 0.72; }
.insight .insight__kicker {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--accent);
  display: block;
  margin-bottom: 10px;
}
.insight h3 { font-family: var(--font-display); font-weight: 400; font-size: clamp(1.3rem, 2.6vw, 1.8rem); }
.insight p { color: var(--muted); max-width: 44em; margin: 0; }

/* Founder / DNA cards */
.founder { border-top: 1px solid var(--line); padding-top: 22px; }
.founder__kicker { font-family: var(--font-mono); font-size: 0.7rem; letter-spacing: 0.2em; text-transform: uppercase; color: var(--accent); display: block; margin-bottom: 12px; }
.founder h3 { font-family: var(--font-display); font-weight: 400; font-size: 1.3rem; }
.founder p { color: var(--muted); font-size: 0.94rem; }

/* Principles */
.principle { border-top: 1px solid var(--line); padding-top: 18px; }
.principle h3 { font-size: 1rem; font-weight: 600; }
.principle p { color: var(--muted); font-size: 0.92rem; margin: 0; }

/* Evidence chain */
.chain { display: flex; flex-wrap: wrap; gap: 10px 16px; align-items: center; }
.chain .link {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 14px 18px;
  min-width: 150px;
}
.chain .link b { display: block; font-family: var(--font-mono); font-size: 0.72rem; letter-spacing: 0.12em; text-transform: uppercase; margin-bottom: 4px; }
.chain .link span { color: var(--muted); font-size: 0.82rem; }
.chain .arrow { color: var(--accent); font-family: var(--font-mono); }

/* Case cards */
.case { border: 1px solid var(--line); border-radius: var(--radius); padding: 26px; }
.case__kicker { font-family: var(--font-mono); font-size: 0.68rem; letter-spacing: 0.18em; text-transform: uppercase; color: var(--muted); display: block; margin-bottom: 12px; }
.case__kicker .flag { color: var(--amber-light); }
.section--dark .case__kicker .flag { color: var(--gate-modify); }
.case h3 { font-family: var(--font-display); font-weight: 400; font-size: 1.3rem; }
.case p { font-size: 0.92rem; color: var(--muted); }
.case .case__stats { display: grid; grid-template-columns: repeat(3, 1fr); gap: 14px; margin-top: 18px; }
.case .case__stats .metric__value { font-size: 1.5rem; }
.case .case__stats .metric { padding-top: 12px; }

/* Forms */
.form { display: grid; gap: 22px; max-width: 620px; }
.form label {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: 8px;
}
.form input, .form textarea {
  width: 100%;
  background: transparent;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  color: var(--fg);
  font-family: var(--font-sans);
  font-size: 1rem;
  padding: 14px 16px;
}
.form input:focus, .form textarea:focus { border-color: var(--accent); outline: none; }
.form textarea { min-height: 140px; resize: vertical; }

/* CTA section */
.cta-final { text-align: left; }
.cta-final .h2 { max-width: 16em; }

/* Horizon steps */
.horizon { border-top: 1px solid var(--line); padding-top: 18px; }
.horizon__num { font-family: var(--font-mono); font-size: 0.7rem; letter-spacing: 0.2em; text-transform: uppercase; color: var(--accent); display: block; margin-bottom: 10px; }
.horizon h3 { font-family: var(--font-display); font-weight: 400; font-size: 1.2rem; }
.horizon p { color: var(--muted); font-size: 0.9rem; margin: 0; }

/* Engagement stages */
.stagefee { border: 1px solid var(--line); border-radius: var(--radius); padding: 24px; display: flex; flex-direction: column; gap: 8px; }
.stagefee__kicker { font-family: var(--font-mono); font-size: 0.7rem; letter-spacing: 0.18em; text-transform: uppercase; color: var(--accent); }
.stagefee h3 { font-family: var(--font-display); font-weight: 400; font-size: 1.35rem; margin: 0; }
.stagefee__fee { font-family: var(--font-mono); font-size: 0.8rem; color: var(--fg); }
.stagefee p { color: var(--muted); font-size: 0.9rem; margin: 0; }

/* Playbook chapter pager */
.chapter-pager { display: flex; justify-content: space-between; gap: 20px; flex-wrap: wrap; }

/* ---------- 9. Motion ---------- */
.reveal {
  opacity: 0;
  transform: translateY(22px);
  transition: opacity var(--dur-section) var(--ease), transform var(--dur-section) var(--ease);
}
.reveal.is-visible { opacity: 1; transform: none; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .reveal { opacity: 1; transform: none; transition: none; }
  *, *::before, *::after { animation: none !important; transition: none !important; }
}

/* ---------- 10. Responsive ---------- */
@media (max-width: 1080px) {
  .nav__links { display: none; }
  .nav__toggle { display: block; }
  .grid--4 { grid-template-columns: repeat(2, 1fr); }
  .footer__inner { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 820px) {
  .grid--3 { grid-template-columns: 1fr; }
  .chapter-list a { grid-template-columns: 52px 1fr; }
  .chapter-list .desc { grid-column: 2; text-align: left; max-width: none; }
  .case .case__stats { grid-template-columns: 1fr; }
}

@media (max-width: 620px) {
  .grid--2, .grid--4 { grid-template-columns: 1fr; }
  .footer__inner { grid-template-columns: 1fr; }
  .kv dd { text-align: left; }
  .kv { grid-template-columns: 1fr; gap: 2px 0; }
  .kv dd { margin-bottom: 8px; }
}

/* ---------- Nav dropdown clickthroughs ---------- */
.nav__item { position: relative; display: flex; align-items: center; }
.nav__item > a {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  font-weight: 500;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  text-decoration: none;
  opacity: 0.82;
  padding: 6px 0;
  border-bottom: 1px solid transparent;
  transition: opacity var(--dur-micro) var(--ease), border-color var(--dur-micro) var(--ease);
}
.nav__item > a:hover { opacity: 1; }
.nav__item > a.is-active { opacity: 1; border-bottom-color: var(--blue-soft); }

.nav__menu {
  position: absolute;
  top: calc(100% + 14px);
  left: -22px;
  min-width: 340px;
  background: var(--ink-2);
  border: 1px solid var(--line-on-dark);
  border-radius: var(--radius);
  padding: 10px;
  opacity: 0;
  visibility: hidden;
  transform: translateY(6px);
  transition: opacity var(--dur-micro) var(--ease),
              transform var(--dur-micro) var(--ease),
              visibility 0s linear var(--dur-micro);
  box-shadow: 0 24px 60px rgba(0, 0, 0, 0.35);
}
.nav__menu--wide { min-width: 380px; max-height: min(70vh, 620px); overflow-y: auto; }
/* invisible hover bridge so the pointer can travel into the panel */
.nav__menu::before {
  content: "";
  position: absolute;
  top: -14px;
  left: 0;
  right: 0;
  height: 14px;
}
.nav__item:hover .nav__menu,
.nav__item:focus-within .nav__menu {
  opacity: 1;
  visibility: visible;
  transform: none;
  transition-delay: 0s;
}
.nav__menu a {
  display: block;
  padding: 12px 14px;
  border-radius: var(--radius);
  text-decoration: none;
  opacity: 1;
  border-bottom: 0;
  text-transform: none;
  letter-spacing: normal;
}
.nav__menu a:hover { background: rgba(244, 242, 236, 0.06); }
.nav__menu a b {
  display: block;
  font-family: var(--font-sans);
  font-size: 0.86rem;
  font-weight: 600;
  color: var(--paper);
  margin-bottom: 2px;
}
.nav__menu a span {
  display: block;
  font-family: var(--font-sans);
  font-size: 0.78rem;
  line-height: 1.45;
  color: var(--muted-on-dark);
}

@media (prefers-reduced-motion: reduce) {
  .nav__menu { transition: none; transform: none; }
}


/* ---------- Mobile refinements (v4) ---------- */
body { overflow-x: clip; }

/* iOS Safari: stable hero height while the URL bar collapses */
@supports (height: 1svh) {
  .hero { min-height: min(92svh, 900px); }
  .hero--short { min-height: 0; }
}

@media (max-width: 620px) {
  .hero { min-height: min(86svh, 720px); }
  .hero .btn-row .btn { width: 100%; justify-content: space-between; }
  .pipeline { display: grid; grid-template-columns: 1fr; gap: 6px; font-size: 0.72rem; }
  .pipeline .sep {
    display: block;
    width: fit-content;
    margin: 0 0 0 26px;
    transform: rotate(90deg); /* the -> becomes a downward arrow: the flow stays visible */
    color: var(--accent);
  }
  .pipeline .step { padding: 10px 14px; }
  .pipeline .gates { display: flex; gap: 8px; flex-wrap: wrap; }
  .pipeline__decision { display: block; }
  .stage-card { padding: 18px; }
  .case { padding: 20px; }
  .chain .link { min-width: 100%; }
  .chain .arrow { display: none; }
  .footer__col a { padding: 4px 0; }
  .nav__wordmark { font-size: 1.15rem; }
}


/* ---------- v5 components ---------- */

/* Decision label above the Scale/Modify/Stop gates (shown on stacked mobile pipeline) */
.pipeline__decision {
  display: none;
  font-family: var(--font-mono);
  font-size: 0.66rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--muted);
  margin-top: 4px;
}

/* The BUSAC flywheel: Identify -> Engineer -> Prove -> Learn -> Scale, back to Identify */
.flywheel { border-bottom: 1px solid var(--line); }
.flywheel__step {
  display: grid;
  grid-template-columns: 130px 260px 1fr;
  gap: 8px 28px;
  align-items: baseline;
  padding: 20px 0;
  border-top: 1px solid var(--line);
}
.flywheel__phase {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  font-weight: 500;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--accent);
}
.flywheel__name { font-family: var(--font-display); font-size: 1.25rem; }
.flywheel__desc { color: var(--muted); font-size: 0.92rem; }
.flywheel__loop {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 16px 0 0;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--muted);
}
.flywheel__loop b { color: var(--accent); font-weight: 500; font-size: 1rem; }
@media (max-width: 820px) {
  .flywheel__step { grid-template-columns: 100px 1fr; }
  .flywheel__desc { grid-column: 2; }
}

/* V1-V4 strip */
.vstrip {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 14px;
  align-items: center;
  font-family: var(--font-mono);
  font-size: 0.74rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}
.vstrip .v {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 8px 12px;
  color: var(--muted);
}
.vstrip .v b { color: var(--fg); font-weight: 500; margin-right: 6px; }
.vstrip .v--verified { border-color: var(--verified); }
.vstrip .v--verified b { color: var(--verified); }
.vstrip .sep { color: var(--accent); }

/* Question line under a pillar heading */
.pillar-q {
  font-family: var(--font-display);
  font-style: italic;
  font-size: 1.15rem;
  color: var(--muted);
  margin-top: 4px;
}


/* Illustrative case outcome points (qualitative, no invented numbers) */
.case__points { display: grid; gap: 14px; margin-top: 20px; border-top: 1px solid var(--line); padding-top: 16px; }
.case__points h4 {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  font-weight: 500;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--accent);
  margin: 0 0 4px;
}
.case__points p { margin: 0; font-size: 0.9rem; color: var(--muted); }


/* Nav CTA as a highlighted button (5 items + 1 action) */
.nav__cta--btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: var(--paper);
  color: var(--ink) !important;
  border: 1px solid var(--paper);
  border-radius: var(--radius);
  padding: 11px 20px;
  border-bottom: 1px solid var(--paper) !important;
  transition: background var(--dur-micro) var(--ease),
              border-color var(--dur-micro) var(--ease),
              color var(--dur-micro) var(--ease);
}
.nav__cta--btn:hover {
  background: var(--blue);
  border-color: var(--blue);
  color: var(--paper) !important;
}
.nav__cta--btn:focus-visible {
  outline: 2px solid var(--blue-soft);
  outline-offset: 3px;
}


/* Footer CTA band: the quiet closing ask above the footer columns */
.footer-cta {
  text-align: center;
  padding: clamp(56px, 9vw, 110px) var(--gutter);
  border-bottom: 1px solid var(--line-on-dark);
}
.footer-cta h2 { margin: 0 0 28px; }
.btn--paper {
  background: var(--paper);
  color: var(--ink);
  border: 1px solid var(--paper);
}
.btn--paper:hover { background: var(--blue); border-color: var(--blue); color: var(--paper); }


/* Floating Let's Talk: fixed bottom-right, appears after the hero, retreats at the footer */
.fab {
  position: fixed;
  right: clamp(16px, 3vw, 36px);
  bottom: calc(clamp(16px, 3vw, 32px) + env(safe-area-inset-bottom, 0px));
  z-index: 90; /* under the nav (100) and the mobile menu */
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 0.74rem;
  font-weight: 500;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  text-decoration: none;
  background: var(--paper);
  color: var(--ink);
  border: 1px solid rgba(11, 21, 32, 0.12);
  border-radius: var(--radius);
  padding: 14px 22px;
  box-shadow: 0 10px 30px rgba(11, 21, 32, 0.28);
  opacity: 0;
  visibility: hidden;
  transform: translateY(14px);
  transition: opacity 0.3s var(--ease), transform 0.3s var(--ease),
              background 0.16s var(--ease), color 0.16s var(--ease),
              visibility 0s linear 0.3s;
}
.fab.is-visible {
  opacity: 1;
  visibility: visible;
  transform: none;
  transition-delay: 0s;
}
.fab:hover { background: var(--blue); color: var(--paper); border-color: var(--blue); }
.fab span { display: inline-block; transition: transform var(--dur-micro) var(--ease); }
.fab:hover span { transform: translateX(3px); }
.fab:focus-visible { outline: 2px solid var(--blue-soft); outline-offset: 3px; }
@media print { .fab { display: none; } }