/* ============================================================
   WHITEBOARD LEARNING — Signal Design System
   AI-powered leadership. Dark navy field. Cyan signal.
   Maps 1:1 to WordPress block theme tokens (theme.json)
   ============================================================ */

@import url('https://api.fontshare.com/v2/css?f[]=satoshi@400,500,700&f[]=general-sans@500,600,700&display=swap');
@import url('https://fonts.googleapis.com/css2?family=Instrument+Serif:ital@1&display=swap');

:root {
  /* ---------- Color (Signal palette) ---------- */
  --navy-deep:  #0B1F3D;    /* primary background */
  --navy:       #0F2A47;    /* surfaces */
  --navy-soft:  #173558;    /* card surfaces / hover */
  --navy-line:  #1F3F66;    /* dividers on dark */
  --ink:        #0B1220;    /* near-black text on light */

  --paper:      #F7F6F2;    /* light frame background */
  --paper-pure: #FBFAF6;    /* card / light surface */
  --rule:       #E3DFD6;    /* dividers on light */

  --blue-mid:    #1E4FA3;   /* mid blue accent (logo-aligned) */
  --blue-bright: #3D8BFF;   /* bright accent */
  --cyan:        #7BD6E8;   /* signal accent — used sparingly */

  --text-on-dark:       #F5F8FF;
  --text-on-dark-muted: #C7D4E8;
  --text-on-dark-faint: #8DA4C7;

  --muted:      #5A5E6B;    /* secondary text on light */
  --faint:      #8E92A0;    /* tertiary text on light */

  /* Semantic roles — default Signal mode is DARK */
  --bg:        var(--navy-deep);
  --surface:   var(--navy);
  --surface-2: var(--navy-soft);
  --border:    var(--navy-line);
  --text:      var(--text-on-dark);
  --text-muted: var(--text-on-dark-muted);
  --text-faint: var(--text-on-dark-faint);
  --accent:    var(--cyan);
  --accent-2:  var(--blue-bright);

  /* ---------- Type ---------- */
  --font-display: 'General Sans', 'Satoshi', -apple-system, BlinkMacSystemFont, system-ui, sans-serif;
  --font-body:    'Satoshi', 'Inter', -apple-system, BlinkMacSystemFont, system-ui, sans-serif;
  --font-serif:   'Instrument Serif', Georgia, serif;  /* reserved for pull-quotes only */
  --font-mono:    'JetBrains Mono', ui-monospace, monospace;

  --text-xs:   0.75rem;
  --text-sm:   0.875rem;
  --text-base: 1rem;
  --text-md:   1.125rem;
  --text-lg:   1.375rem;
  --text-xl:   1.75rem;
  --text-2xl:  2.5rem;
  --text-3xl:  3.5rem;
  --text-hero: clamp(2.5rem, 6vw, 5.25rem);

  /* ---------- Spacing (8pt base) ---------- */
  --s-1: 0.25rem; --s-2: 0.5rem; --s-3: 0.75rem; --s-4: 1rem;
  --s-6: 1.5rem; --s-8: 2rem; --s-12: 3rem; --s-16: 4rem;
  --s-20: 5rem; --s-24: 6rem; --s-32: 8rem; --s-40: 10rem;

  /* ---------- Layout ---------- */
  --container:        1280px;
  --container-narrow: 880px;
  --container-prose:  680px;

  /* ---------- Motion ---------- */
  --ease:       cubic-bezier(0.16, 1, 0.3, 1);
  --ease-quick: cubic-bezier(0.4, 0, 0.2, 1);

  --shadow-sm: 0 1px 2px rgba(0,0,0,0.2);
  --shadow-md: 0 18px 48px -16px rgba(0,0,0,0.4);
  --shadow-lg: 0 30px 80px -24px rgba(0,0,0,0.5);
  --glow:      0 0 24px rgba(123,214,232,0.25);

  /* ---------- Legacy aliases (inline-style references) ---------- */
  --highlight: var(--cyan);
  --ink-soft:  var(--text-on-dark-muted);
}

/* Inside light-flipped sections, legacy aliases resolve to ink/muted */
.surface-light {
  --highlight: var(--blue-mid);
  --ink-soft:  var(--muted);
}

/* ---------- Reset ---------- */
*, *::before, *::after { box-sizing: border-box; }
* { margin: 0; padding: 0; }

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-body);
  font-size: var(--text-base);
  line-height: 1.6;
  color: var(--text);
  background: var(--bg);
  font-feature-settings: "kern", "liga", "calt", "ss01";
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
}

img, svg, video { display: block; max-width: 100%; height: auto; }
button { font: inherit; color: inherit; background: none; border: 0; cursor: pointer; }
a { color: inherit; text-decoration: none; }

::selection { background: var(--cyan); color: var(--navy-deep); }

/* ---------- Typography ---------- */
.eyebrow {
  font-family: var(--font-body);
  font-size: var(--text-xs);
  font-weight: 600;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--accent);
  display: inline-flex;
  align-items: center;
  gap: var(--s-3);
}
.eyebrow::before {
  content: "";
  width: 28px;
  height: 1px;
  background: var(--accent);
  display: inline-block;
}

h1, .h1 {
  font-family: var(--font-display);
  font-size: var(--text-hero);
  font-weight: 600;
  line-height: 1.02;
  letter-spacing: -0.03em;
  color: var(--text);
}
h1 em, .h1 em, h1 .hl, .h1 .hl { color: var(--accent); font-style: normal; }

h2, .h2 {
  font-family: var(--font-display);
  font-size: clamp(2rem, 4.4vw, 3.5rem);
  font-weight: 600;
  line-height: 1.05;
  letter-spacing: -0.025em;
}
h2 em, .h2 em, h2 .hl, .h2 .hl { color: var(--accent); font-style: normal; }

h3, .h3 {
  font-family: var(--font-display);
  font-size: clamp(1.5rem, 2.6vw, 2rem);
  font-weight: 600;
  line-height: 1.15;
  letter-spacing: -0.015em;
}

h4, .h4 {
  font-family: var(--font-display);
  font-size: var(--text-md);
  font-weight: 600;
  line-height: 1.3;
  letter-spacing: -0.005em;
}

p { max-width: 65ch; }

/* Serif is reserved for pull-quotes only */
.pullquote {
  font-family: var(--font-serif);
  font-style: italic;
  font-size: clamp(1.5rem, 2.4vw, 2rem);
  line-height: 1.25;
  letter-spacing: -0.005em;
  color: var(--text);
}
.pullquote em { color: var(--accent); font-style: italic; }

.lede {
  font-family: var(--font-body);
  font-size: var(--text-md);
  line-height: 1.55;
  color: var(--text-muted);
  font-weight: 400;
  max-width: 56ch;
}

.mono {
  font-family: var(--font-display);
  font-variant-numeric: tabular-nums;
  letter-spacing: 0.02em;
}

/* ---------- Layout primitives ---------- */
.container        { width: 100%; max-width: var(--container);        margin: 0 auto; padding: 0 var(--s-8); }
.container-narrow { width: 100%; max-width: var(--container-narrow); margin: 0 auto; padding: 0 var(--s-8); }
.container-prose  { width: 100%; max-width: var(--container-prose);  margin: 0 auto; padding: 0 var(--s-8); }

section { padding: clamp(var(--s-16), 10vw, var(--s-32)) 0; }
.section-tight { padding: clamp(var(--s-12), 6vw, var(--s-20)) 0; }

/* ---------- Surface variants ----------
   Default body is dark navy. .surface-light flips a section to the cream frame
   for editorial / case study / about content. */
.surface-light {
  background: var(--paper);
  color: var(--ink);
  --text: var(--ink);
  --text-muted: var(--muted);
  --text-faint: var(--faint);
  --border: var(--rule);
  --surface: var(--paper-pure);
  --surface-2: #FFFFFF;
  --accent: var(--blue-mid);
}
.surface-light .eyebrow { color: var(--blue-mid); }
.surface-light .eyebrow::before { background: var(--blue-mid); }
.surface-light h1 em, .surface-light .h1 em, .surface-light h1 .hl,
.surface-light h2 em, .surface-light .h2 em, .surface-light h2 .hl { color: var(--blue-mid); }

.divider { height: 1px; background: var(--border); border: 0; }

/* ---------- Header ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(11, 31, 61, 0.78);
  backdrop-filter: blur(18px);
  -webkit-backdrop-filter: blur(18px);
  border-bottom: 1px solid transparent;
  transition: border-color 0.3s var(--ease), background 0.3s var(--ease);
}
.site-header.is-scrolled {
  border-bottom-color: rgba(123, 214, 232, 0.12);
  background: rgba(11, 31, 61, 0.92);
}
.site-header__inner {
  max-width: var(--container);
  margin: 0 auto;
  padding: var(--s-4) var(--s-8);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--s-12);
}
.brand {
  display: flex;
  align-items: center;
  gap: var(--s-3);
  font-family: var(--font-display);
  font-size: var(--text-md);
  font-weight: 600;
  letter-spacing: -0.01em;
  line-height: 1;
  color: var(--text-on-dark);
}
.brand svg { flex-shrink: 0; }
.brand__mark { color: var(--cyan); }

/* Logo image (replaces inline SVG + wordmark span) */
.brand__logo {
  display: block;
  height: 36px;
  width: auto;
  object-fit: contain;
  flex-shrink: 0;
}
.site-footer .brand__logo { height: 32px; }
@media (max-width: 720px) {
  .brand__logo { height: 30px; }
}

.nav { display: flex; align-items: center; gap: var(--s-8); }
.nav a {
  font-size: var(--text-sm);
  color: var(--text-on-dark-muted);
  font-weight: 500;
  transition: color 0.2s;
  position: relative;
}
.nav a:hover { color: var(--cyan); }
.nav a.is-current { color: var(--text-on-dark); }
.nav a.is-current::after {
  content: "";
  position: absolute;
  left: 0; right: 0; bottom: -6px;
  height: 1px;
  background: var(--cyan);
}

.menu-toggle { display: none; color: var(--text-on-dark); }

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--s-2);
  padding: 0.875rem 1.5rem;
  font-family: var(--font-display);
  font-size: var(--text-sm);
  font-weight: 600;
  letter-spacing: -0.005em;
  line-height: 1;
  border-radius: 999px;
  border: 1px solid transparent;
  transition: all 0.2s var(--ease-quick);
  white-space: nowrap;
  cursor: pointer;
}

/* Primary button on dark surfaces: white pill with navy text */
.btn--primary {
  background: #FFFFFF;
  color: var(--navy-deep);
}
.btn--primary:hover {
  background: var(--cyan);
  color: var(--navy-deep);
  transform: translateY(-1px);
  box-shadow: var(--glow);
}

/* Ghost button on dark surfaces */
.btn--ghost {
  color: var(--text-on-dark);
  border-color: rgba(199, 212, 232, 0.3);
  background: transparent;
}
.btn--ghost:hover {
  border-color: var(--cyan);
  color: var(--cyan);
}

.btn--link {
  padding: 0.5rem 0;
  border-radius: 0;
  background: transparent;
  color: var(--text-on-dark);
  border-bottom: 1px solid rgba(199, 212, 232, 0.3);
  font-weight: 500;
}
.btn--link:hover { color: var(--cyan); border-bottom-color: var(--cyan); }

/* Primary button on LIGHT surfaces flips to navy fill */
.surface-light .btn--primary {
  background: var(--navy-deep);
  color: #FFFFFF;
}
.surface-light .btn--primary:hover {
  background: var(--blue-mid);
  box-shadow: 0 12px 28px -10px rgba(30,79,163,0.45);
}
.surface-light .btn--ghost {
  color: var(--ink);
  border-color: var(--rule);
}
.surface-light .btn--ghost:hover {
  border-color: var(--ink);
}
.surface-light .btn--link {
  color: var(--ink);
  border-bottom-color: var(--ink);
}
.surface-light .btn--link:hover { color: var(--blue-mid); border-bottom-color: var(--blue-mid); }

.btn .arrow { transition: transform 0.2s var(--ease-quick); }
.btn:hover .arrow { transform: translateX(4px); }

/* ---------- Footer ---------- */
.site-footer {
  background: #06152C;
  color: var(--text-on-dark);
  padding: var(--s-24) 0 var(--s-8);
  border-top: 1px solid var(--navy-line);
}
.site-footer a {
  color: var(--text-on-dark-muted);
  transition: color 0.2s;
  font-size: var(--text-sm);
}
.site-footer a:hover { color: var(--cyan); }
.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: var(--s-12);
  margin-bottom: var(--s-16);
}
.footer-grid h4 {
  font-family: var(--font-body);
  font-size: var(--text-xs);
  text-transform: uppercase;
  letter-spacing: 0.14em;
  color: var(--cyan);
  margin-bottom: var(--s-4);
  font-weight: 600;
}
.footer-grid ul { list-style: none; display: flex; flex-direction: column; gap: var(--s-3); }
.footer-meta {
  display: flex;
  justify-content: space-between;
  padding-top: var(--s-6);
  border-top: 1px solid rgba(199, 212, 232, 0.1);
  font-size: var(--text-xs);
  color: var(--text-on-dark-faint);
}

/* ---------- Reveal animation ---------- */
.reveal { opacity: 0; transform: translateY(16px); transition: opacity 0.9s var(--ease), transform 0.9s var(--ease); }
.reveal.is-visible { opacity: 1; transform: none; }

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

/* ---------- Mobile ---------- */
@media (max-width: 880px) {
  .site-header__inner { padding: var(--s-4) var(--s-6); }
  .nav {
    display: none;
    position: fixed;
    inset: 60px 0 0 0;
    flex-direction: column;
    align-items: flex-start;
    gap: 0;
    background: var(--navy-deep);
    padding: var(--s-8);
    border-top: 1px solid var(--navy-line);
  }
  .nav.is-open { display: flex; }
  .nav a {
    padding: var(--s-4) 0;
    font-size: var(--text-lg);
    font-family: var(--font-display);
    font-weight: 500;
    width: 100%;
    border-bottom: 1px solid var(--navy-line);
  }
  .menu-toggle { display: inline-flex; padding: 0; width: 32px; height: 32px; align-items: center; justify-content: center; }
  .container, .container-narrow, .container-prose { padding: 0 var(--s-6); }
  .footer-grid { grid-template-columns: 1fr 1fr; gap: var(--s-8); }
}