/* ============================================================
   ThinkForAI — site.css
   Complete stylesheet for AI for Business pillar page
   ============================================================ */

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
  font-size: 1rem;
  line-height: 1.75;
  color: #1a1a2e;
  background: #ffffff;
}

img { max-width: 100%; height: auto; display: block; }
a  { color: #2563eb; text-decoration: none; }
a:hover { text-decoration: underline; color: #1d4ed8; }

ul, ol { padding-left: 1.5rem; }
li { margin-bottom: 0.4rem; }

p { margin-bottom: 1.15rem; }
p:last-child { margin-bottom: 0; }

/* ── Typography Scale ─────────────────────────────────────── */
h1, h2, h3, h4, h5 {
  font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
  font-weight: 700;
  line-height: 1.25;
  color: #0f172a;
  margin-bottom: 0.75rem;
}

h1 { font-size: clamp(1.75rem, 4vw, 2.75rem); }
h2 { font-size: clamp(1.35rem, 3vw, 1.9rem); margin-top: 2.5rem; }
h3 { font-size: clamp(1.1rem, 2.5vw, 1.35rem); margin-top: 1.75rem; font-weight: 600; }
h4 { font-size: 1.05rem; font-weight: 600; margin-top: 1.25rem; }

/* ── Layout: Container ────────────────────────────────────── */
.container {
  max-width: 900px;
  margin: 0 auto;
  padding: 0 1.25rem;
}

/* ── Site Header ──────────────────────────────────────────── */
.site-header {
  background: #0f172a;
  padding: 0;
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: 0 2px 8px rgba(0,0,0,.25);
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 2rem;
  padding: 0.9rem 1.25rem;
  max-width: 1100px;
  margin: 0 auto;
}

.site-logo {
  font-size: 1.25rem;
  font-weight: 800;
  color: #60a5fa;
  letter-spacing: -0.5px;
  white-space: nowrap;
}
.site-logo:hover { color: #93c5fd; text-decoration: none; }

.nav-links {
  display: flex;
  list-style: none;
  gap: 1.5rem;
  padding: 0;
  margin: 0 0 0 auto;
  flex-wrap: wrap;
}

.nav-links li { margin: 0; }

.nav-links a {
  color: #cbd5e1;
  font-size: 0.9rem;
  font-weight: 500;
  transition: color .15s;
}
.nav-links a:hover { color: #ffffff; text-decoration: none; }

/* ── Article Hero ─────────────────────────────────────────── */
.article-hero {
  background: linear-gradient(135deg, #0f172a 0%, #1e3a5f 100%);
  color: #f1f5f9;
  padding: 3rem 0 2.5rem;
}

.breadcrumb {
  font-size: 0.82rem;
  color: #94a3b8;
  margin-bottom: 1rem;
}
.breadcrumb a { color: #60a5fa; }
.breadcrumb a:hover { color: #93c5fd; }

.article-title {
  color: #f1f5f9;
  font-size: clamp(1.5rem, 4vw, 2.4rem);
  line-height: 1.2;
  margin-bottom: 1rem;
  max-width: 820px;
}

.article-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem 1.5rem;
  font-size: 0.85rem;
  color: #94a3b8;
  margin-bottom: 1.5rem;
}

.article-intro-callout {
  background: rgba(96, 165, 250, 0.15);
  border-left: 4px solid #60a5fa;
  padding: 1rem 1.25rem;
  border-radius: 0 8px 8px 0;
  max-width: 700px;
  font-size: 0.95rem;
}
.article-intro-callout p { color: #e2e8f0; margin: 0; }
.article-intro-callout strong { color: #93c5fd; }

/* ── Article Body ─────────────────────────────────────────── */
.article-body {
  padding-top: 2.5rem;
  padding-bottom: 3rem;
}

.article-section {
  margin-bottom: 3rem;
  padding-bottom: 2.5rem;
  border-bottom: 1px solid #e2e8f0;
}
.article-section:last-of-type { border-bottom: none; }

/* ── Table of Contents ────────────────────────────────────── */
.toc-section { margin-bottom: 3rem; }

.toc-box {
  background: #f8fafc;
  border: 1px solid #e2e8f0;
  border-radius: 12px;
  padding: 1.75rem 2rem;
}

.toc-title {
  font-size: 1.1rem;
  font-weight: 700;
  color: #0f172a;
  margin: 0 0 1rem 0;
  padding-bottom: 0.75rem;
  border-bottom: 2px solid #2563eb;
  display: inline-block;
}

.toc-list {
  columns: 2;
  column-gap: 2rem;
  padding-left: 1.5rem;
}

.toc-list li {
  margin-bottom: 0.5rem;
  break-inside: avoid;
  font-size: 0.9rem;
}

.toc-list a {
  color: #374151;
  font-weight: 500;
}
.toc-list a:hover { color: #2563eb; }

/* ── Callout Boxes ────────────────────────────────────────── */
.callout-box {
  border-radius: 10px;
  padding: 1.25rem 1.5rem;
  margin: 1.75rem 0;
  font-size: 0.95rem;
}
.callout-box p { margin: 0; }

.insight-callout {
  background: #eff6ff;
  border-left: 4px solid #2563eb;
  color: #1e40af;
}
.insight-callout strong { color: #1e3a8a; }

.stat-callout {
  background: #f0fdf4;
  border-left: 4px solid #16a34a;
  color: #166534;
}
.stat-callout strong { color: #14532d; }

.so-what-callout {
  background: #fefce8;
  border-left: 4px solid #ca8a04;
  color: #713f12;
}
.so-what-callout strong { color: #92400e; }

/* ── Example & Case Study Boxes ──────────────────────────── */
.example-box,
.case-study-box {
  background: #f8fafc;
  border: 1px solid #e2e8f0;
  border-radius: 10px;
  padding: 1.5rem;
  margin: 1.75rem 0;
}

.example-box h4,
.case-study-box h4 {
  font-size: 0.95rem;
  font-weight: 700;
  color: #1e40af;
  margin-top: 0;
  margin-bottom: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.03em;
  font-size: 0.78rem;
}

.example-box p:last-child,
.case-study-box p:last-child { margin-bottom: 0; }

/* ── Data Tables ──────────────────────────────────────────── */
.data-table-wrapper {
  overflow-x: auto;
  margin: 2rem 0;
  border-radius: 10px;
  border: 1px solid #e2e8f0;
  box-shadow: 0 1px 4px rgba(0,0,0,.06);
}

.data-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.88rem;
}

.data-table caption {
  caption-side: top;
  font-weight: 700;
  font-size: 0.85rem;
  color: #475569;
  text-align: left;
  padding: 0.85rem 1rem 0.5rem;
  background: #f8fafc;
  border-bottom: 1px solid #e2e8f0;
  border-radius: 10px 10px 0 0;
}

.data-table thead {
  background: #1e3a5f;
  color: #f1f5f9;
}

.data-table thead th {
  padding: 0.75rem 1rem;
  text-align: left;
  font-weight: 600;
  font-size: 0.82rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  white-space: nowrap;
}

.data-table tbody tr {
  border-bottom: 1px solid #f1f5f9;
  transition: background .1s;
}

.data-table tbody tr:hover { background: #f8fafc; }

.data-table tbody td {
  padding: 0.7rem 1rem;
  vertical-align: top;
  color: #334155;
  line-height: 1.5;
}

.data-table tbody tr:last-child { border-bottom: none; }

.total-row td {
  background: #eff6ff;
  font-weight: 700;
  color: #1e3a8a !important;
  border-top: 2px solid #bfdbfe;
}

/* ── Framework & Step Lists ───────────────────────────────── */
.framework-list {
  list-style: none;
  padding: 0;
  margin: 1rem 0 1.5rem;
}

.framework-list li {
  padding: 0.85rem 1.1rem 0.85rem 1.1rem;
  margin-bottom: 0.6rem;
  background: #f8fafc;
  border-left: 4px solid #2563eb;
  border-radius: 0 8px 8px 0;
  line-height: 1.55;
  font-size: 0.95rem;
}

.framework-list li strong {
  color: #1e40af;
  display: inline-block;
  min-width: 110px;
}

.numbered-steps {
  padding-left: 0;
  list-style: none;
  counter-reset: step-counter;
  margin: 1rem 0 1.5rem;
}

.numbered-steps li {
  counter-increment: step-counter;
  padding: 0.85rem 1rem 0.85rem 3.25rem;
  margin-bottom: 0.6rem;
  background: #f8fafc;
  border-radius: 8px;
  position: relative;
  font-size: 0.95rem;
  line-height: 1.55;
  border: 1px solid #e2e8f0;
}

.numbered-steps li::before {
  content: counter(step-counter);
  position: absolute;
  left: 0.9rem;
  top: 0.8rem;
  background: #2563eb;
  color: white;
  width: 1.6rem;
  height: 1.6rem;
  border-radius: 50%;
  font-size: 0.8rem;
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
  line-height: 1;
}

.numbered-steps li strong { color: #1e40af; }

/* ── Comparison Table ─────────────────────────────────────── */
.comparison-table-wrapper { margin: 2rem 0; }

/* ── Resource Links ───────────────────────────────────────── */
.supporting-articles-section h3 {
  font-size: 1rem;
  color: #0f172a;
  padding-bottom: 0.4rem;
  border-bottom: 2px solid #e2e8f0;
  margin-bottom: 0.75rem;
}

.resource-links {
  list-style: none;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 0.4rem;
  margin-bottom: 1.75rem;
}

.resource-links li { margin: 0; }

.resource-links a {
  display: block;
  padding: 0.5rem 0.75rem;
  font-size: 0.875rem;
  color: #374151;
  border: 1px solid #e5e7eb;
  border-radius: 6px;
  transition: all .15s;
  line-height: 1.4;
  background: #fafafa;
}

.resource-links a::before {
  content: "→ ";
  color: #2563eb;
  font-weight: 700;
}

.resource-links a:hover {
  background: #eff6ff;
  border-color: #bfdbfe;
  color: #1e40af;
  text-decoration: none;
}

/* ── FAQ Section ──────────────────────────────────────────── */
.faq-section { margin-bottom: 3rem; }

.faq-item {
  border: 1px solid #e2e8f0;
  border-radius: 10px;
  margin-bottom: 0.85rem;
  overflow: hidden;
}

.faq-question {
  font-size: 1rem;
  font-weight: 600;
  color: #0f172a;
  padding: 1.1rem 1.25rem;
  margin: 0;
  background: #f8fafc;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: space-between;
  line-height: 1.4;
}

.faq-question::after {
  content: "+";
  font-size: 1.4rem;
  font-weight: 300;
  color: #2563eb;
  flex-shrink: 0;
  margin-left: 1rem;
  line-height: 1;
}

.faq-item.open .faq-question::after { content: "−"; }

.faq-answer {
  padding: 1.1rem 1.25rem;
  background: #ffffff;
  border-top: 1px solid #e2e8f0;
  font-size: 0.95rem;
  color: #374151;
  display: none;
}

.faq-item.open .faq-answer { display: block; }

/* ── Checklist ────────────────────────────────────────────── */
.checklist-container {
  background: #f8fafc;
  border: 1px solid #e2e8f0;
  border-radius: 12px;
  padding: 1.75rem;
}

.checklist-container h3 {
  margin-top: 1.25rem;
  font-size: 1rem;
  color: #0f172a;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid #e2e8f0;
  margin-bottom: 0.75rem;
}

.checklist-container h3:first-child { margin-top: 0; }

.checklist {
  list-style: none;
  padding: 0;
  margin-bottom: 0.5rem;
}

.checklist-item {
  padding: 0.5rem 0.5rem 0.5rem 2rem;
  position: relative;
  font-size: 0.9rem;
  color: #374151;
  border-bottom: 1px solid #f1f5f9;
  margin-bottom: 0;
}

.checklist-item:last-child { border-bottom: none; }

.checklist-item::before {
  content: "☐";
  position: absolute;
  left: 0.25rem;
  color: #2563eb;
  font-size: 1.1rem;
  line-height: 1.4;
}

/* ── Banner Placeholders ──────────────────────────────────── */
.banner-placeholder {
  margin: 2rem 0;
  border-radius: 8px;
  overflow: hidden;
  text-align: center;
  background: #f1f5f9;
  border: 1px solid #e2e8f0;
}

.banner-placeholder .banner-image {
  width: 100%;
  max-height: 120px;
  object-fit: cover;
  display: block;
}

/* Hide broken banner images gracefully */
.banner-placeholder .banner-image[src=""] ,
.banner-placeholder .banner-image:not([src]) {
  display: none;
}

/* ── Article Conclusion ───────────────────────────────────── */
.article-conclusion {
  background: linear-gradient(135deg, #eff6ff 0%, #f0fdf4 100%);
  border: 1px solid #bfdbfe;
  border-radius: 14px;
  padding: 2.5rem;
  margin-bottom: 3rem;
}

.article-conclusion h2 {
  margin-top: 0;
  color: #1e3a8a;
}

/* ── Author Bio ───────────────────────────────────────────── */
.author-bio-section {
  margin-bottom: 3rem;
}

.author-bio-card {
  display: flex;
  gap: 1.5rem;
  background: #f8fafc;
  border: 1px solid #e2e8f0;
  border-radius: 12px;
  padding: 1.75rem;
  margin-bottom: 1rem;
  align-items: flex-start;
}

.author-avatar {
  width: 64px;
  height: 64px;
  min-width: 64px;
  background: #1e3a5f;
  color: #60a5fa;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 800;
  font-size: 0.85rem;
  letter-spacing: 0.05em;
}

.author-name {
  font-size: 1.05rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
  margin-top: 0;
}

.author-description {
  font-size: 0.9rem;
  color: #475569;
  margin-bottom: 0.5rem;
}

.author-expertise {
  font-size: 0.85rem;
  color: #64748b;
}

.disclosure-note {
  font-size: 0.8rem;
  color: #64748b;
  background: #f1f5f9;
  border-radius: 8px;
  padding: 1rem 1.25rem;
  border-left: 3px solid #94a3b8;
  line-height: 1.55;
}

/* ── Site Footer ──────────────────────────────────────────── */
.site-footer {
  background: #0f172a;
  color: #94a3b8;
  padding: 3rem 0 1.5rem;
  margin-top: 2rem;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 2rem;
  padding-bottom: 2rem;
  border-bottom: 1px solid #1e293b;
  margin-bottom: 1.5rem;
}

.footer-heading {
  color: #f1f5f9;
  font-size: 0.9rem;
  font-weight: 700;
  margin-bottom: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 0.07em;
}

.footer-description {
  font-size: 0.87rem;
  line-height: 1.6;
  margin-bottom: 0;
}

.footer-links {
  list-style: none;
  padding: 0;
  margin: 0;
}

.footer-links li { margin-bottom: 0.45rem; }

.footer-links a {
  color: #94a3b8;
  font-size: 0.87rem;
  transition: color .15s;
}
.footer-links a:hover { color: #60a5fa; text-decoration: none; }

.footer-bottom {
  font-size: 0.82rem;
  color: #64748b;
  text-align: center;
}

.footer-bottom a { color: #64748b; }
.footer-bottom a:hover { color: #94a3b8; }

/* ── Utility: strong/em ───────────────────────────────────── */
strong { font-weight: 700; color: #0f172a; }
em { font-style: italic; }

/* ── Inline code ──────────────────────────────────────────── */
code {
  background: #f1f5f9;
  border: 1px solid #e2e8f0;
  border-radius: 4px;
  padding: 0.1em 0.4em;
  font-size: 0.88em;
  font-family: 'Cascadia Code', 'Fira Code', monospace;
}

/* ── Responsive ───────────────────────────────────────────── */
@media (max-width: 768px) {
  .toc-list { columns: 1; }

  .footer-grid {
    grid-template-columns: 1fr 1fr;
  }

  .author-bio-card {
    flex-direction: column;
    align-items: center;
    text-align: center;
  }

  .resource-links {
    grid-template-columns: 1fr;
  }

  .site-nav {
    flex-wrap: wrap;
    gap: 0.75rem;
  }

  .nav-links {
    gap: 1rem;
    margin: 0;
  }
}

@media (max-width: 540px) {
  .footer-grid { grid-template-columns: 1fr; gap: 1.5rem; }
  .article-meta { flex-direction: column; gap: 0.3rem; }
  h2 { margin-top: 2rem; }
  .data-table { font-size: 0.8rem; }
  .data-table thead th, .data-table tbody td { padding: 0.6rem 0.7rem; }
}

/* ── Smooth section anchors (offset for sticky header) ─────── */
:target { scroll-margin-top: 70px; }

/* ── Print styles ─────────────────────────────────────────── */
@media print {
  .site-header, .site-footer, .banner-placeholder { display: none; }
  .article-hero { background: #fff; color: #000; padding: 1rem 0; }
  .article-title { color: #000; }
  a { color: #000; text-decoration: underline; }
}