/* ==========================================================================
   DESIGN SYSTEM: Technical Broadsheet
   Typography: Newsreader (headlines) + Work Sans (body/UI)
   Palette: Deep Charcoal, Pure White, Subtle Teal, Neutral Grays
   Grid: 12-column fixed, 1280px max, 64px margins
   ========================================================================== */

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

:root {
  --surface: #f9f9f9;
  --surface-container-low: #f3f3f4;
  --surface-container: #eeeeee;
  --surface-container-high: #e8e8e8;
  --on-surface: #1a1c1c;
  --on-surface-variant: #45474a;
  --primary: #121417;
  --on-primary: #ffffff;
  --secondary: #2D4A4B;
  --secondary-container: #C4D7D6;
  --on-secondary-container: #1c2b8b;
  --outline: #76777b;
  --outline-variant: #c6c6ca;
  --border: #E5E7EB;
  --white: #ffffff;
  --footer-bg: #F9FAFB;

  --font-serif: 'Newsreader', Georgia, serif;
  --font-sans: 'Work Sans', system-ui, sans-serif;

  --container-max: 1280px;
  --gutter: 32px;
  --margin-desktop: 64px;
  --section-gap: 128px;
  --stack-sm: 12px;
  --stack-md: 24px;
  --stack-lg: 48px;
}

html {
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-sans);
  font-size: 16px;
  font-weight: 400;
  line-height: 1.6;
  color: var(--on-surface);
  background-color: var(--surface-container-low);
}

img {
  display: block;
  max-width: 100%;
  height: auto;
}

a {
  color: inherit;
  text-decoration: none;
}

ul, ol {
  list-style: none;
}

/* --- Typography Scale --- */
.display-xl {
  font-family: var(--font-serif);
  font-size: 72px;
  font-weight: 600;
  line-height: 1.1;
  letter-spacing: -0.02em;
}

.headline-lg {
  font-family: var(--font-serif);
  font-size: 48px;
  font-weight: 500;
  line-height: 1.2;
  letter-spacing: -0.01em;
}

.headline-md {
  font-family: var(--font-serif);
  font-size: 32px;
  font-weight: 500;
  line-height: 1.3;
}

.body-lg {
  font-family: var(--font-sans);
  font-size: 20px;
  font-weight: 400;
  line-height: 1.6;
}

.body-md {
  font-family: var(--font-sans);
  font-size: 16px;
  font-weight: 400;
  line-height: 1.6;
}

.label-caps {
  font-family: var(--font-sans);
  font-size: 12px;
  font-weight: 600;
  line-height: 1.4;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

.meta-sm {
  font-family: var(--font-sans);
  font-size: 14px;
  font-weight: 400;
  line-height: 1.5;
}

/* --- Top Bar (Advertorial label) --- */
.top-bar {
  background-color: var(--surface-container-high);
  color: var(--on-surface-variant);
  text-align: center;
  padding: 6px 0;
  font-family: var(--font-sans);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

/* --- Header --- */
.header {
  background-color: var(--white);
  border-bottom: 1px solid var(--border);
  top: 0;
  z-index: 50;
}

.header-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--margin-desktop);
  height: 80px;
}

.header-logo {
  height: 36px;
  width: auto;
}

.btn-primary {
  display: inline-block;
  background-color: var(--primary);
  color: var(--on-primary);
  font-family: var(--font-sans);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  padding: 12px 28px;
  border: none;
  cursor: pointer;
  transition: opacity 0.2s ease;
  text-decoration: none;
}

.btn-primary:hover {
  opacity: 0.88;
}

/* --- Main Content Area --- */
.main-content {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: var(--stack-lg) var(--margin-desktop) var(--section-gap);
}

/* --- Hero Section --- */
.hero-section {
  display: grid;
  grid-template-columns: repeat(12, 1fr);
  gap: var(--gutter);
  margin-bottom: 60px;
}

.hero-text {
  grid-column: span 8;
}

.hero-meta {
  grid-column: span 4;
  align-self: end;
}

.hero-tag {
  display: inline-block;
  background-color: var(--secondary-container);
  color: var(--on-secondary-container);
  padding: 4px 12px;
  font-family: var(--font-sans);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  margin-bottom: 24px;
}

.hero-text h1 {
  margin-bottom: 24px;
}

.hero-lead {
  max-width: 640px;
  border-left: 4px solid var(--secondary);
  padding-left: 24px;
  color: var(--on-surface-variant);
}

.hero-author-block {
  border-top: 1px solid #d1d5db;
  padding-top: 24px;
}

.hero-author-label {
  color: var(--on-surface-variant);
  margin-bottom: 8px;
}

.hero-author-name {
  color: var(--primary);
}

.hero-author-title {
  color: var(--on-surface-variant);
  font-style: italic;
  margin-top: 4px;
}

/* --- Featured Imagery (Hero Image) --- */
.hero-bg {
  width: 100%;
  aspect-ratio: 21 / 9;
  overflow: hidden;
  margin-bottom: var(--section-gap);
  filter: grayscale(100%);
  transition: filter 0.7s ease;
  cursor: crosshair;
}

.hero-bg:hover {
  filter: grayscale(0%);
}

.hero-bg img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

/* --- Editorial Grid (8col + 4col sidebar) --- */
.editorial-section {
  display: grid;
  grid-template-columns: repeat(12, 1fr);
  gap: var(--gutter);
}

.col-8 {
  grid-column: span 8;
}

.col-4 {
  grid-column: span 4;
}

.col-12 {
  grid-column: span 12;
}

/* --- Narrative Column --- */
.narrative-col > * + * {
  margin-top: var(--stack-lg);
}

.narrative-col h2 {
  border-bottom: 1px solid var(--border);
  padding-bottom: 16px;
}

.narrative-col p {
  color: var(--on-surface);
}

.narrative-col p + p {
  margin-top: var(--stack-md);
}

/* --- Checklist Card --- */
.checklist-card {
  background-color: var(--white);
  border: 1px solid var(--border);
  padding: 48px;
  position: relative;
}

.checklist-title {
  font-family: var(--font-serif);
  font-size: 32px;
  font-weight: 500;
  line-height: 1.3;
  margin-bottom: 24px;
}

.checklist-item {
  display: flex;
  gap: 16px;
  align-items: flex-start;
  margin-bottom: 16px;
  font-size: 16px;
  line-height: 1.6;
}

.checklist-marker {
  flex-shrink: 0;
  width: 8px;
  height: 8px;
  margin-top: 10px;
  background-color: var(--secondary);
}

/* --- Sidebar --- */
.col-4 > * + * {
  margin-top: 64px;
}

/* Sidebar: Technical Insights */
.sidebar-insights {
  background-color: var(--surface-container-low);
  padding: 32px;
  border-left: 2px solid var(--secondary);
}

.sidebar-insights h4 {
  color: var(--secondary);
  margin-bottom: 24px;
}

.sidebar-insight-item + .sidebar-insight-item {
  margin-top: 32px;
}

.sidebar-insight-item .insight-title {
  font-weight: 700;
  color: var(--primary);
  margin-bottom: 4px;
}

.sidebar-insight-item p {
  color: var(--on-surface-variant);
}

/* Sidebar: Glossary */
.sidebar-glossary h4 {
  color: var(--on-surface-variant);
  border-bottom: 1px solid var(--border);
  padding-bottom: 8px;
  margin-bottom: 24px;
}

.glossary-term {
  margin-bottom: 24px;
}

.glossary-term dt {
  font-family: var(--font-sans);
  font-size: 14px;
  font-weight: 700;
  margin-bottom: 4px;
}

.glossary-term dd {
  font-family: var(--font-sans);
  font-size: 14px;
  color: var(--on-surface-variant);
  padding-left: 16px;
  border-left: 1px solid var(--border);
}

/* Sidebar: Resource Parameters */
.sidebar-params {
  border: 1px solid var(--border);
  padding: 32px;
}

.sidebar-params h4 {
  color: var(--on-surface-variant);
  margin-bottom: 24px;
}

.param-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 8px 0;
  border-bottom: 1px solid #f3f4f6;
  font-size: 14px;
}

.param-value {
  font-family: 'Courier New', monospace;
  color: var(--secondary);
}

/* Sidebar: Image */
.sidebar-image {
  aspect-ratio: 1 / 1;
  overflow: hidden;
  filter: grayscale(100%);
}

.sidebar-image img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

/* --- Image Frame (content image in main col) --- */
.image-frame {
  position: relative;
  overflow: hidden;
}

.image-frame img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

/* --- CTA Block --- */
.cta-block {
  background-color: var(--primary);
  color: var(--on-primary);
  padding: 64px;
  display: flex;
  flex-direction: row;
  align-items: center;
  gap: 48px;
  margin-top: 64px;
}

.cta-block-text {
  flex: 1;
}

.cta-block-text h2 {
  color: var(--on-primary);
  margin-bottom: 16px;
  border-bottom: none;
  padding-bottom: 0;
}

.cta-block-text p {
  color: var(--on-primary);
  opacity: 0.8;
}

.cta-btn {
  display: inline-block;
  background-color: var(--secondary);
  color: var(--on-primary);
  font-family: var(--font-sans);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  padding: 20px 40px;
  white-space: nowrap;
  transition: background-color 0.2s ease, color 0.2s ease;
}

.cta-btn:hover {
  background-color: var(--on-primary);
  color: var(--primary);
}

/* --- CTA Logo Section (full-width offer) --- */
.cta-logo-section {
  text-align: center;
  padding: 80px 0;
}

.cta-logo-inner {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--margin-desktop);
}

.cta-logo-inner h2 {
  margin-bottom: 40px;
}

.cta-logo-link {
  display: inline-block;
}

.cta-logo {
  max-width: 180px;
  margin: 0 auto;
  outline: 3px solid var(--secondary);
  outline-offset: 8px;
}

.mt-md {
  margin-top: var(--stack-md);
}

.mt-sm {
  margin-top: var(--stack-sm);
}

.mt-xl {
  margin-top: 80px;
}

.mb-xl {
  margin-bottom: 80px;
}

/* --- Disclaimer Section (above footer, not in it) --- */
.disclaimer-section {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--margin-desktop) var(--stack-lg);
}

.disclaimer-text {
  font-family: var(--font-sans);
  font-size: 12px;
  color: var(--outline);
  line-height: 1.7;
  letter-spacing: 0.02em;
}

/* --- Footer --- */
.footer {
  background-color: var(--footer-bg);
  border-top: 1px solid var(--border);
}

.footer-container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 96px var(--margin-desktop);
  display: grid;
  grid-template-columns: repeat(12, 1fr);
  gap: var(--gutter);
  align-items: start;
}

.footer-brand {
  grid-column: span 4;
}

.footer-brand-name {
  font-family: var(--font-serif);
  font-size: 20px;
  font-weight: 700;
  color: var(--primary);
  margin-bottom: 24px;
}

.footer-copy {
  font-family: var(--font-sans);
  font-size: 12px;
  color: #6b7280;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  line-height: 1.8;
}

.footer-nav {
  grid-column: span 5;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.footer-nav a {
  font-family: var(--font-sans);
  font-size: 12px;
  color: #6b7280;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  text-decoration: underline;
  transition: color 0.2s ease;
}

.footer-nav a:hover {
  color: var(--primary);
}

.footer-contact {
  grid-column: span 3;
}

.footer-contact-label {
  font-family: var(--font-sans);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--primary);
  margin-bottom: 16px;
}

.footer-contact p {
  font-family: var(--font-sans);
  font-size: 12px;
  color: #6b7280;
  line-height: 1.8;
  letter-spacing: 0.02em;
}

/* --- Byline Component --- */
.byline {
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 16px 0;
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  margin-bottom: var(--stack-lg);
}

.byline-divider {
  width: 1px;
  height: 16px;
  background-color: var(--outline-variant);
}

.byline span {
  font-family: var(--font-sans);
  font-size: 14px;
  color: var(--on-surface-variant);
}

/* --- Responsive --- */
@media (max-width: 1024px) {
  .display-xl {
    font-size: 48px;
  }

  .headline-lg {
    font-size: 36px;
  }

  .headline-md {
    font-size: 26px;
  }

  .hero-section {
    grid-template-columns: 1fr;
  }

  .hero-text {
    grid-column: span 1;
  }

  .hero-meta {
    grid-column: span 1;
  }

  .editorial-section {
    grid-template-columns: 1fr;
  }

  .col-8,
  .col-4,
  .col-12 {
    grid-column: span 1;
  }

  .cta-block {
    flex-direction: column;
    padding: 48px 32px;
  }

  .footer-container {
    grid-template-columns: 1fr;
    padding: 48px var(--gutter);
  }

  .footer-brand,
  .footer-nav,
  .footer-contact {
    grid-column: span 1;
  }

  .main-content {
    padding-left: var(--gutter);
    padding-right: var(--gutter);
  }

  .header-inner {
    padding: 0 var(--gutter);
  }

  .disclaimer-section {
    padding-left: var(--gutter);
    padding-right: var(--gutter);
  }

  .cta-logo-inner {
    padding: 0 var(--gutter);
  }
}

@media (max-width: 640px) {
  .display-xl {
    font-size: 36px;
  }

  .headline-lg {
    font-size: 28px;
  }

  .headline-md {
    font-size: 22px;
  }

  .body-lg {
    font-size: 18px;
  }

  .header-inner {
    padding: 0 16px;
    height: 64px;
  }

  .main-content {
    padding-left: 16px;
    padding-right: 16px;
    padding-top: var(--stack-md);
  }

  .hero-bg {
    aspect-ratio: 16 / 9;
    margin-bottom: 64px;
  }

  .checklist-card {
    padding: 24px;
  }

  .cta-block {
    padding: 32px 20px;
  }

  .cta-logo {
    max-width: 100%;
  }

  .disclaimer-section {
    padding-left: 16px;
    padding-right: 16px;
  }

  .footer-container {
    padding: 40px 16px;
  }
}