/* ==========================================================================
   CAIRN ETP — Enterprise Trust Plane Design System (cairnetp.com)
   Palette: Graphite (#23272E), Slate (#3B4450), Limestone (#F5F5F1), Oxide Green (#5B6F5A)
   ========================================================================== */

:root {
  /* Graphite, Slate & Limestone Palette */
  --bg-dark: #1b1e24;
  --bg-graphite: #23272e;
  --bg-slate: #2e353f;
  --bg-slate-card: #3b4450;
  
  --color-limestone: #f5f5f1;
  --color-stone-muted: #9ca3af;
  --color-granite-dark: #4b5563;
  
  /* Oxide Green Signature Accent */
  --color-oxide-green: #5b6f5a;
  --color-oxide-hover: #6e866d;
  --color-oxide-dim: rgba(91, 111, 90, 0.18);
  --border-color: rgba(91, 111, 90, 0.3);
  --border-highlight: #5b6f5a;
  
  --text-main: #f5f5f1;
  --text-secondary: #9ca3af;
  --text-muted: #6b7280;
  
  /* Typography */
  --font-heading: 'IBM Plex Sans', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-body: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-mono: 'IBM Plex Mono', monospace;
  
  /* Radii */
  --radius-sm: 4px;
  --radius-md: 6px;
  --radius-lg: 8px;
  
  --shadow-card: 0 10px 30px rgba(0, 0, 0, 0.45);
  --transition-fast: 0.15s ease-in-out;
  --transition-normal: 0.25s ease-in-out;
}

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

html, body {
  width: 100%;
  max-width: 100%;
  overflow-x: hidden;
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
  background-color: var(--bg-dark);
  color: var(--text-main);
  font-family: var(--font-body);
  -webkit-font-smoothing: antialiased;
}

body {
  line-height: 1.65;
  background: var(--bg-dark);
  min-height: 100vh;
}

img, video, iframe, svg {
  max-width: 100%;
  height: auto;
}

pre, code {
  max-width: 100%;
  overflow-x: auto;
  font-family: var(--font-mono);
  white-space: pre-wrap;
  word-break: break-word;
}

/* Typography Utilities */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  font-weight: 600;
  line-height: 1.15;
  color: var(--text-main);
  letter-spacing: -0.02em;
}

.text-oxide {
  color: var(--color-oxide-green);
}

.badge-authority {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  padding: 0.35rem 0.85rem;
  border-radius: var(--radius-sm);
  font-family: var(--font-mono);
  font-size: 0.775rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  background: var(--color-oxide-dim);
  border: 1px solid var(--border-color);
  color: var(--color-oxide-green);
}

/* Layout Containers */
.container {
  max-width: 1200px;
  width: 100%;
  margin: 0 auto;
  padding: 0 2rem;
}

.section-spacing {
  padding: 6.5rem 0;
  border-bottom: 1px solid rgba(255, 255, 255, 0.06);
}

/* Header & Navigation */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 100;
  transition: var(--transition-normal);
  padding: 1.25rem 0;
  background: rgba(27, 30, 36, 0.95);
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.site-header.scrolled {
  padding: 0.85rem 0;
  border-bottom-color: var(--border-color);
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.5);
}

.nav-wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.brand-logo {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  text-decoration: none;
  color: var(--text-main);
  font-family: var(--font-heading);
  font-size: 1.25rem;
  font-weight: 700;
  letter-spacing: 0.05em;
}

.brand-logo img {
  width: 28px;
  height: 28px;
}

.brand-tag {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  padding: 0.1rem 0.4rem;
  border-radius: 2px;
  background: var(--color-oxide-dim);
  color: var(--color-oxide-green);
  border: 1px solid var(--border-color);
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 2rem;
  list-style: none;
}

.nav-link {
  text-decoration: none;
  color: var(--text-secondary);
  font-size: 0.9rem;
  font-weight: 500;
  transition: var(--transition-fast);
  padding: 0.2rem 0;
}

.nav-link:hover, .nav-link.active {
  color: var(--text-main);
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 1rem;
}

/* Mobile Toggle Hamburger */
.mobile-toggle-btn {
  display: none;
  background: transparent;
  border: 1px solid var(--bg-slate-card);
  color: var(--text-main);
  width: 38px;
  height: 38px;
  border-radius: var(--radius-sm);
  font-size: 1.1rem;
  cursor: pointer;
  align-items: center;
  justify-content: center;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.6rem;
  padding: 0.75rem 1.6rem;
  border-radius: var(--radius-sm);
  font-family: var(--font-heading);
  font-size: 0.9rem;
  font-weight: 600;
  text-decoration: none;
  cursor: pointer;
  transition: var(--transition-fast);
  border: 1px solid transparent;
  white-space: nowrap;
}

.btn-oxide {
  background: var(--color-oxide-green);
  color: #0d100d;
  border-color: var(--color-oxide-green);
}

.btn-oxide:hover {
  background: var(--color-oxide-hover);
  border-color: var(--color-oxide-hover);
}

.btn-secondary {
  background: var(--bg-graphite);
  border-color: var(--bg-slate-card);
  color: var(--text-main);
}

.btn-secondary:hover {
  background: var(--bg-slate);
  border-color: var(--color-stone-muted);
}

.btn-linkedin {
  background: #0a66c2;
  color: #ffffff;
  border-color: rgba(255, 255, 255, 0.2);
}

.btn-linkedin:hover {
  background: #004182;
}

.btn-outline {
  background: transparent;
  border-color: var(--bg-slate-card);
  color: var(--text-secondary);
}

.btn-outline:hover {
  border-color: var(--color-oxide-green);
  color: var(--text-main);
}

/* Problem-First Hero Section */
.hero-section {
  padding-top: 11rem;
  padding-bottom: 6rem;
  text-align: left;
}

.category-statement {
  font-size: 4.5rem;
  font-weight: 700;
  letter-spacing: -0.035em;
  margin: 1.25rem 0 1.25rem 0;
  max-width: 980px;
  color: var(--text-main);
  line-height: 1.08;
}

.problem-box {
  background: var(--bg-graphite);
  border-left: 3px solid var(--color-oxide-green);
  border-radius: var(--radius-sm);
  padding: 2.25rem;
  margin: 2.5rem 0 3rem 0;
  max-width: 860px;
}

.problem-box-title {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--color-oxide-green);
  margin-bottom: 1rem;
}

.problem-list {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem 2rem;
  list-style: none;
}

.problem-item {
  font-size: 1.05rem;
  color: var(--text-main);
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.problem-item i {
  color: var(--color-oxide-green);
  font-size: 0.85rem;
}

.solution-statement {
  font-size: 1.35rem;
  color: var(--text-main);
  font-weight: 500;
  margin-bottom: 2.5rem;
  max-width: 840px;
}

.hero-cta-wrap {
  display: flex;
  align-items: center;
  gap: 1.25rem;
  flex-wrap: wrap;
}

/* Statement Callout Card */
.statement-card {
  background: var(--bg-graphite);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 2.5rem;
  margin-top: 3rem;
}

.statement-quote {
  font-size: 1.5rem;
  font-weight: 600;
  color: var(--text-main);
  line-height: 1.4;
  margin-bottom: 0.75rem;
}

/* Target Sectors Bar */
.sectors-bar {
  padding: 3.5rem 0;
  background: #14171c;
  border-top: 1px solid rgba(255, 255, 255, 0.06);
  border-bottom: 1px solid rgba(255, 255, 255, 0.06);
}

.sectors-label {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--text-muted);
  margin-bottom: 1.25rem;
}

.sectors-list {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.5rem;
  flex-wrap: wrap;
}

.sector-tag {
  font-family: var(--font-heading);
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--text-secondary);
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.sector-tag i {
  color: var(--color-oxide-green);
  font-size: 0.9rem;
}

/* The Trust Layer Category Diagram */
.trust-plane-comparison {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2.5rem;
  margin-top: 3rem;
}

.diagram-card {
  background: var(--bg-graphite);
  border: 1px solid var(--bg-slate-card);
  border-radius: var(--radius-md);
  padding: 2.25rem;
}

.diagram-card.cairn-plane {
  border-color: var(--border-highlight);
  box-shadow: 0 0 25px rgba(91, 111, 90, 0.12);
}

.diagram-card-title {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 1.5rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.diagram-flow-chain {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.flow-step-box {
  background: #181b20;
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: var(--radius-sm);
  padding: 0.85rem 1.25rem;
  font-family: var(--font-heading);
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-main);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.flow-step-box.highlight {
  border-color: var(--color-oxide-green);
  color: var(--color-oxide-green);
  background: var(--color-oxide-dim);
}

.flow-step-arrow {
  text-align: center;
  color: var(--color-stone-muted);
  font-size: 0.85rem;
}

/* Pillar Architecture Cards */
.gartner-pillar-card {
  background: var(--bg-graphite);
  border: 1px solid var(--bg-slate-card);
  border-radius: var(--radius-md);
  padding: 2.5rem;
  margin-bottom: 2.5rem;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2.5rem;
  align-items: center;
}

.gartner-pillar-content h3 {
  font-size: 1.75rem;
  margin-bottom: 0.35rem;
}

.gartner-pillar-role {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--color-oxide-green);
  text-transform: uppercase;
  margin-bottom: 1.25rem;
}

.gartner-pillar-desc p {
  color: var(--text-secondary);
  font-size: 0.975rem;
  line-height: 1.7;
  margin-bottom: 1rem;
}

.gartner-pillar-visual {
  border-radius: var(--radius-sm);
  overflow: hidden;
  border: 1px solid var(--bg-slate-card);
}

/* ==========================================================================
   Book Showcase & Author Layout (book.html)
   ========================================================================== */
.book-hero {
  padding-top: 11rem;
  padding-bottom: 6rem;
}

.book-hero-grid {
  display: grid;
  grid-template-columns: 1fr 420px;
  gap: 4rem;
  align-items: center;
}

.book-cover-stage {
  display: flex;
  justify-content: center;
  align-items: center;
  background: var(--bg-graphite);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 2.5rem;
  box-shadow: var(--shadow-card);
}

.book-cover-image {
  max-width: 100%;
  height: auto;
  border-radius: var(--radius-sm);
  box-shadow: 0 15px 35px rgba(0, 0, 0, 0.6);
  transition: transform var(--transition-normal);
}

.book-cover-image:hover {
  transform: translateY(-4px);
}

.author-card {
  background: var(--bg-graphite);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 3.5rem;
  display: grid;
  grid-template-columns: 120px 1fr;
  gap: 3rem;
  align-items: flex-start;
  box-shadow: var(--shadow-card);
}

.author-avatar {
  width: 110px;
  height: 110px;
  border-radius: 50%;
  background: var(--color-oxide-green);
  display: flex;
  align-items: center;
  justify-content: center;
  color: #0d100d;
  font-size: 2.75rem;
  font-family: var(--font-heading);
  font-weight: 700;
  box-shadow: 0 8px 20px rgba(91, 111, 90, 0.3);
}

/* Modal Dialog for Demonstration Request */
.modal-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  background: rgba(20, 23, 28, 0.9);
  backdrop-filter: blur(8px);
  z-index: 1000;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  visibility: hidden;
  transition: var(--transition-fast);
  padding: 1.5rem;
}

.modal-overlay.open {
  opacity: 1;
  visibility: visible;
}

.modal-container {
  background: var(--bg-graphite);
  border: 1px solid var(--border-highlight);
  border-radius: var(--radius-md);
  max-width: 560px;
  width: 100%;
  padding: 2.5rem;
  box-shadow: var(--shadow-card);
}

.modal-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 1.5rem;
  border-bottom: 1px solid var(--bg-slate-card);
  padding-bottom: 1rem;
}

.modal-close-btn {
  background: transparent;
  border: none;
  color: var(--text-secondary);
  font-size: 1.4rem;
  cursor: pointer;
}

.form-group {
  margin-bottom: 1.25rem;
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}

.form-group label {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--text-secondary);
  text-transform: uppercase;
}

.form-input {
  background: #181b20;
  border: 1px solid var(--bg-slate-card);
  border-radius: var(--radius-sm);
  padding: 0.75rem 1rem;
  color: var(--text-main);
  font-family: var(--font-body);
  font-size: 0.95rem;
  outline: none;
}

.form-input:focus {
  border-color: var(--color-oxide-green);
}

/* Footer */
.site-footer {
  background: #14171c;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  padding: 4rem 0 2rem 0;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 2.5rem;
  margin-bottom: 3rem;
}

.footer-brand p {
  color: var(--text-secondary);
  font-size: 0.9rem;
  margin-top: 0.85rem;
  max-width: 340px;
}

.footer-col h4 {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-main);
  margin-bottom: 1.1rem;
}

.footer-col ul {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.55rem;
}

.footer-col a {
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.875rem;
  transition: var(--transition-fast);
}

.footer-col a:hover {
  color: var(--color-oxide-green);
}

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.06);
  padding-top: 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  color: var(--text-muted);
  font-size: 0.825rem;
  flex-wrap: wrap;
  gap: 0.75rem;
}

/* Responsive Media Queries */
@media (max-width: 992px) {
  .category-statement { font-size: 3.25rem; }
  .problem-list { grid-template-columns: 1fr; }
  .trust-plane-comparison { grid-template-columns: 1fr; }
  .gartner-pillar-card { grid-template-columns: 1fr; }
  .book-hero-grid { grid-template-columns: 1fr; gap: 2.5rem; }
  .author-card { grid-template-columns: 1fr; gap: 1.75rem; padding: 2.25rem; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 768px) {
  .category-statement { font-size: 2.35rem; }
  .solution-statement { font-size: 1.15rem; }
  .sectors-list { justify-content: center; }
  .mobile-toggle-btn { display: flex; }
  .nav-links {
    position: fixed;
    top: 60px;
    left: 0;
    width: 100vw;
    background: #181b20;
    border-bottom: 1px solid var(--bg-slate-card);
    flex-direction: column;
    padding: 1.5rem;
    gap: 1.25rem;
    opacity: 0;
    visibility: hidden;
    transform: translateY(-10px);
    transition: var(--transition-normal);
  }
  .nav-links.mobile-open {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
  }
}