/* Ghost card styles for validation */
.kg-width-wide { max-width: 1040px; margin: 0 auto; }
.kg-width-full { max-width: 100%; margin: 0 auto; }

/* ==========================================================================
   FastenerInsight — Design System
   ========================================================================== */

:root {
  --fi-black: #111418;
  --fi-charcoal: #1c2126;
  --fi-slate-900: #232a31;
  --fi-slate-700: #3d4750;
  --fi-slate-500: #626d78;
  --fi-slate-300: #9aa5b1;
  --fi-slate-100: #e4e8ec;
  --fi-white: #ffffff;
  --fi-steel-700: #35526b;
  --fi-steel-500: #4d7690;
  --fi-steel-300: #7fa0b5;
  --fi-bg: var(--fi-white);
  --fi-bg-inverse: var(--fi-charcoal);
  --fi-text: var(--fi-slate-900);
  --fi-text-muted: var(--fi-slate-500);
  --fi-border: var(--fi-slate-100);
  --fi-accent: var(--fi-steel-700);
  --fi-font-sans: -apple-system, BlinkMacSystemFont, "Inter", "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --fi-font-mono: "IBM Plex Mono", "SFMono-Regular", Consolas, Menlo, monospace;
  --fi-content-width: 760px;
  --fi-wide-width: 1200px;
  --fi-radius: 4px;
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  font-family: var(--fi-font-sans);
  font-size: 17px;
  line-height: 1.65;
  color: var(--fi-text);
  background: var(--fi-bg);
  -webkit-font-smoothing: antialiased;
}

a { color: var(--fi-accent); text-decoration: none; }
a:hover { text-decoration: underline; }
img { max-width: 100%; display: block; }

/* Container */
.container {
  max-width: var(--fi-wide-width);
  margin: 0 auto;
  padding: 0 24px;
}
.container--narrow {
  max-width: 780px;
  margin: 0 auto;
  padding: 0 24px;
}

/* ============ SITE HEADER ============ */
.site-header {
  border-bottom: 1px solid var(--fi-border);
  background: var(--fi-bg);
  position: sticky;
  top: 0;
  z-index: 40;
}
.site-header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 18px 24px;
  max-width: var(--fi-wide-width);
  margin: 0 auto;
}
.site-logo {
  font-family: var(--fi-font-mono);
  font-weight: 600;
  font-size: 19px;
  letter-spacing: -0.02em;
  color: var(--fi-black);
}
.site-logo span { color: var(--fi-steel-500); }
.site-nav { display: flex; gap: 28px; }
.site-nav a {
  color: var(--fi-slate-700);
  font-size: 15px;
  font-weight: 500;
}
.site-nav a:hover { color: var(--fi-black); text-decoration: none; }

/* ============ HERO ============ */
.hero {
  background: var(--fi-bg-inverse);
  color: var(--fi-slate-100);
  padding: 96px 24px 88px;
}
.hero__inner {
  max-width: 780px;
  margin: 0 auto;
  text-align: left;
}
.hero__badge {
  font-family: var(--fi-font-mono);
  text-transform: uppercase;
  letter-spacing: 0.14em;
  font-size: 12.5px;
  color: var(--fi-steel-300);
  margin-bottom: 18px;
}
.hero h1 {
  font-size: clamp(32px, 5vw, 48px);
  line-height: 1.15;
  font-weight: 700;
  letter-spacing: -0.02em;
  margin: 0 0 20px;
  color: var(--fi-white);
}
.hero__sub {
  font-size: 19px;
  line-height: 1.6;
  color: var(--fi-slate-300);
  max-width: 620px;
  margin: 0 0 32px;
}
.hero__actions { display: flex; gap: 14px; flex-wrap: wrap; }
.hero__stats {
  display: flex;
  gap: 40px;
  margin-top: 48px;
  padding-top: 32px;
  border-top: 1px solid rgba(255,255,255,0.1);
}
.hero__stat-num {
  font-family: var(--fi-font-mono);
  font-size: 28px;
  font-weight: 700;
  color: var(--fi-white);
}
.hero__stat-label {
  font-size: 13px;
  color: var(--fi-slate-300);
  margin-top: 4px;
}
.hero__visual { display: none; }

/* ============ BUTTONS ============ */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 22px;
  border-radius: var(--fi-radius);
  font-size: 15px;
  font-weight: 600;
  border: 1px solid transparent;
  cursor: pointer;
  text-decoration: none;
  line-height: 1;
}
.btn--primary {
  background: var(--fi-white);
  color: var(--fi-black);
}
.btn--primary:hover { background: var(--fi-slate-100); text-decoration: none; }
.btn--ghost {
  background: transparent;
  color: var(--fi-white);
  border-color: var(--fi-slate-700);
}
.btn--ghost:hover { border-color: var(--fi-slate-300); text-decoration: none; }
.btn-primary {
  background: var(--fi-white);
  color: var(--fi-black);
}
.btn-primary:hover { background: var(--fi-slate-100); text-decoration: none; }
.btn-secondary {
  background: transparent;
  color: var(--fi-white);
  border-color: var(--fi-slate-700);
}
.btn-secondary:hover { border-color: var(--fi-slate-300); text-decoration: none; }

/* ============ SECTION SCAFFOLDING ============ */
.section {
  padding: 64px 24px;
  border-bottom: 1px solid var(--fi-border);
}
.section--alt { background: var(--fi-slate-100); border-bottom: none; }
.section.tools-section { background: var(--fi-slate-100); border-bottom: none; }
.section__header {
  text-align: center;
  max-width: var(--fi-wide-width);
  margin: 0 auto 40px;
}
.section-eyebrow {
  font-family: var(--fi-font-mono);
  text-transform: uppercase;
  letter-spacing: 0.12em;
  font-size: 12px;
  color: var(--fi-steel-700);
  margin: 0 0 8px;
}
.section-eyebrow--light { color: var(--fi-steel-300); }
.section__header h2 {
  font-size: 28px;
  font-weight: 700;
  margin: 0 0 10px;
}
.section__header p {
  font-size: 16px;
  color: var(--fi-text-muted);
  margin: 0;
}
.section-header {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  max-width: var(--fi-wide-width);
  margin: 0 auto 32px;
}
.section-header h2 {
  font-size: 24px;
  font-weight: 700;
  margin: 0;
}
.section-link {
  font-size: 14px;
  font-weight: 600;
  color: var(--fi-slate-500);
}

/* ============ FILTER BAR ============ */
.filter-bar {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 40px;
}
.filter-btn {
  display: inline-block;
  padding: 8px 18px;
  border-radius: 20px;
  font-size: 13px;
  font-weight: 500;
  border: 1px solid var(--fi-border);
  background: transparent;
  color: var(--fi-slate-500);
  cursor: pointer;
  transition: all 0.15s ease;
}
.filter-btn:hover {
  border-color: var(--fi-accent);
  color: var(--fi-accent);
}
.filter-btn.active {
  background: var(--fi-accent);
  color: var(--fi-white);
  border-color: var(--fi-accent);
}

/* ============ ARTICLE GRID ============ */
.articles-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
  max-width: var(--fi-wide-width);
  margin: 0 auto;
}
@media (max-width: 980px) { .articles-grid { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 640px) { .articles-grid { grid-template-columns: 1fr; } }

/* ============ CARD ============ */
.card {
  display: flex;
  flex-direction: column;
  border: 1px solid var(--fi-border);
  border-radius: var(--fi-radius);
  overflow: hidden;
  background: var(--fi-bg);
  transition: border-color .15s ease, transform .15s ease;
  position: relative;
}
.card:hover {
  border-color: var(--fi-slate-300);
  transform: translateY(-2px);
}
.card--featured { grid-column: 1 / -1; display: grid; grid-template-columns: 1fr; }
.card__accent {
  height: 3px;
  background: var(--fi-accent);
  flex-shrink: 0;
}
.card__body { padding: 20px 22px 24px; }
.card__cat {
  font-family: var(--fi-font-mono);
  font-size: 11.5px;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--fi-steel-700);
  margin-bottom: 10px;
  display: inline-block;
}
.card h3, .card h4 {
  font-size: 18px;
  line-height: 1.35;
  margin: 0 0 8px;
  color: var(--fi-black);
}
.card h3 a, .card h4 a { color: inherit; text-decoration: none; }
.card h3 a:hover, .card h4 a:hover { color: var(--fi-accent); }
.card__excerpt {
  font-size: 14.5px;
  color: var(--fi-text-muted);
  margin: 0 0 14px;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}
.card__meta {
  font-size: 13px;
  color: var(--fi-slate-500);
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
}
.card__meta-dot {
  width: 3px;
  height: 3px;
  border-radius: 50%;
  background: var(--fi-slate-300);
}
.ai-chip {
  font-size: 11px;
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 2px 8px;
  background: var(--fi-slate-100);
  border-radius: 3px;
  color: var(--fi-slate-500);
}
.card__read-more {
  margin-top: 14px;
  font-size: 14px;
  font-weight: 600;
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

/* ============ ARTICLES LIST (compact) ============ */
.articles-list {
  display: flex;
  flex-direction: column;
  max-width: var(--fi-wide-width);
  margin: 0 auto;
}
.article-item {
  display: flex;
  gap: 16px;
  padding: 20px 0;
  border-bottom: 1px solid var(--fi-border);
  align-items: flex-start;
}
.article-item:last-child { border-bottom: none; }
.article-item__num {
  flex-shrink: 0;
  font-family: var(--fi-font-mono);
  font-size: 13px;
  color: var(--fi-slate-300);
  width: 28px;
  text-align: right;
}
.article-item__content { flex: 1; }
.article-item__content h4 {
  font-size: 16px;
  margin: 0 0 6px;
}
.article-item__content h4 a { color: var(--fi-black); text-decoration: none; }
.article-item__content h4 a:hover { color: var(--fi-accent); }
.article-item__content p {
  font-size: 14px;
  color: var(--fi-text-muted);
  margin: 0 0 8px;
}
.article-item__meta {
  font-size: 13px;
  color: var(--fi-slate-500);
  display: flex;
  align-items: center;
  gap: 8px;
}

/* ============ PAGINATION ============ */
.pagination {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 16px;
  padding: 40px 0;
  font-size: 14px;
  color: var(--fi-slate-500);
}
.pagination__current { font-family: var(--fi-font-mono); font-size: 13px; }

/* ============ STANDARDS INDEX ============ */
.standards-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 20px;
  max-width: var(--fi-wide-width);
  margin: 0 auto;
}
.std-card {
  display: block;
  border: 1px solid var(--fi-border);
  border-radius: var(--fi-radius);
  padding: 24px;
  cursor: pointer;
  color: inherit;
  text-decoration: none;
  transition: border-color .15s ease, transform .15s ease;
  background: var(--fi-bg);
}
.std-card:hover {
  border-color: var(--fi-accent);
  transform: translateY(-2px);
}
.std-card__code {
  font-family: var(--fi-font-mono);
  font-size: 16px;
  font-weight: 700;
  color: var(--fi-accent);
  margin-bottom: 6px;
}
.std-card__title {
  font-size: 15px;
  font-weight: 600;
  color: var(--fi-black);
  margin-bottom: 8px;
  line-height: 1.35;
}
.std-card__desc {
  font-size: 13.5px;
  color: var(--fi-text-muted);
  line-height: 1.5;
  margin-bottom: 12px;
}
.std-card__tags { display: flex; flex-wrap: wrap; gap: 6px; }
.tag {
  display: inline-block;
  font-size: 11px;
  font-family: var(--fi-font-mono);
  padding: 3px 8px;
  background: var(--fi-slate-100);
  border-radius: 3px;
  color: var(--fi-slate-700);
}

/* ============ TOOLS SECTION ============ */
.tools-row {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  max-width: var(--fi-wide-width);
  margin: 0 auto;
}
@media (max-width: 900px) { .tools-row { grid-template-columns: 1fr; } }
.tool-card {
  display: block;
  background: var(--fi-white);
  border: 1px solid var(--fi-slate-300);
  border-radius: var(--fi-radius);
  padding: 26px 24px;
  cursor: pointer;
  color: inherit;
  text-decoration: none;
  transition: border-color .15s ease, transform .15s ease;
}
.tool-card:hover {
  border-color: var(--fi-accent);
  transform: translateY(-2px);
}
.tool-card__icon, .tool-card-icon {
  width: 40px;
  height: 40px;
  border-radius: var(--fi-radius);
  background: var(--fi-bg-inverse);
  color: var(--fi-white);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 16px;
}
.tool-card h4 { font-size: 17px; margin: 0 0 8px; }
.tool-card p {
  font-size: 14.5px;
  color: var(--fi-text-muted);
  margin: 0 0 16px;
}
.tool-card__cta, .tool-link {
  font-size: 14px;
  font-weight: 600;
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

/* ============ GLOSSARY ============ */
.glossary-row {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
  max-width: var(--fi-wide-width);
  margin: 0 auto;
}
@media (max-width: 700px) { .glossary-row { grid-template-columns: 1fr; } }
.gloss-item { padding: 20px 0; }
.gloss-item__term {
  font-size: 15px;
  font-weight: 600;
  color: var(--fi-black);
  margin-bottom: 6px;
}
.gloss-item__def {
  font-size: 14px;
  color: var(--fi-text-muted);
  line-height: 1.55;
}

/* ============ NEWSLETTER ============ */
.newsletter {
  background: var(--fi-bg-inverse);
  color: var(--fi-white);
  padding: 56px 40px;
  border-radius: var(--fi-radius);
  text-align: center;
}
.newsletter h2 {
  font-size: 26px;
  margin: 10px 0 8px;
}
.newsletter p {
  color: var(--fi-slate-300);
  font-size: 15px;
  max-width: 480px;
  margin: 0 auto 28px;
}
.newsletter__form { display: flex; gap: 10px; max-width: 440px; margin: 0 auto; flex-wrap: wrap; justify-content: center; }
.newsletter__input {
  flex: 1;
  min-width: 200px;
  padding: 12px 16px;
  border-radius: var(--fi-radius);
  border: 1px solid var(--fi-slate-700);
  background: transparent;
  color: var(--fi-white);
  font-size: 15px;
}
.newsletter__input::placeholder { color: var(--fi-slate-500); }
.newsletter__submit {
  padding: 12px 24px;
  border-radius: var(--fi-radius);
  border: none;
  background: var(--fi-white);
  color: var(--fi-black);
  font-weight: 600;
  font-size: 15px;
  cursor: pointer;
}
.newsletter__submit:hover { background: var(--fi-slate-100); }
.newsletter__note {
  display: block;
  font-size: 12.5px;
  color: var(--fi-slate-500);
  margin-top: 12px;
  width: 100%;
}

/* ============ SITE FOOTER ============ */
.site-footer {
  padding: 48px 24px 32px;
  border-top: 1px solid var(--fi-border);
  font-size: 14px;
  color: var(--fi-slate-500);
}
.site-footer a { color: var(--fi-slate-700); }
.site-footer a:hover { color: var(--fi-black); }
.footer-meta {
  margin-top: 28px;
  padding-top: 20px;
  border-top: 1px solid var(--fi-border);
  font-size: 12.5px;
  color: var(--fi-slate-300);
}
.reveal { opacity: 1; transition: opacity 0.6s ease; }
.fade-up, .fade-up-2, .fade-up-3, .fade-up-4 { opacity: 1; }

/* ============ HERO DIAGRAM ============ */
.hero__diagram {
  border: 1px solid rgba(255,255,255,0.1);
  border-radius: var(--fi-radius);
  overflow: hidden;
}
.hero__diagram-header {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 12px 16px;
  background: rgba(255,255,255,0.04);
}
.hero__diagram-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
}
.hero__diagram-title {
  font-family: var(--fi-font-mono);
  font-size: 11px;
  color: var(--fi-slate-300);
  margin-left: auto;
}
.hero__diagram-body { padding: 16px; }
.grade-row { display: flex; align-items: center; gap: 12px; margin-bottom: 8px; }
.grade-label {
  font-family: var(--fi-font-mono);
  font-size: 12px;
  color: var(--fi-slate-300);
  width: 36px;
  text-align: right;
}
.grade-bar-wrap { flex: 1; height: 14px; background: rgba(255,255,255,0.06); border-radius: 2px; overflow: hidden; }
.grade-bar { height: 100%; border-radius: 2px; }
.grade-val {
  font-family: var(--fi-font-mono);
  font-size: 11px;
  color: var(--fi-slate-300);
  width: 60px;
}

/* ============ POST TEMPLATE ============ */
.post-header { max-width: var(--fi-content-width); margin: 56px auto 32px; padding: 0 24px; }
.post-header__inner { max-width: var(--fi-content-width); margin: 0 auto; }
.post-header__back { font-size: 14px; margin-bottom: 16px; display: inline-block; }
.post-header__cats { display: flex; gap: 8px; margin-bottom: 12px; flex-wrap: wrap; }
.post-tag-link {
  font-family: var(--fi-font-mono);
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--fi-steel-700);
}
.post-tag { font-family: var(--fi-font-mono); font-size: 12px; text-transform: uppercase; letter-spacing: 0.08em; color: var(--fi-steel-700); }
.post-header h1 {
  font-size: clamp(30px, 4.4vw, 42px);
  line-height: 1.2;
  font-weight: 700;
  letter-spacing: -0.02em;
  margin: 14px 0 18px;
}
.post-excerpt { font-size: 19px; color: var(--fi-text-muted); line-height: 1.55; }
.post-header__meta {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-top: 24px;
  padding-top: 20px;
  border-top: 1px solid var(--fi-border);
  font-size: 14px;
  color: var(--fi-slate-500);
  flex-wrap: wrap;
}
.post-progress {
  position: fixed;
  top: 0;
  left: 0;
  height: 3px;
  background: var(--fi-accent);
  z-index: 50;
  transition: width 0.1s linear;
}
.post-feature-image { max-width: var(--fi-wide-width); margin: 0 auto 48px; padding: 0 24px; }
.post-feature-image img { border-radius: var(--fi-radius); width: 100%; }
.post-content {
  max-width: var(--fi-content-width);
  margin: 0 auto;
  padding: 0 24px 64px;
  font-size: 18px;
  line-height: 1.75;
}
.post-content h2 { font-size: 26px; margin: 44px 0 18px; letter-spacing: -0.01em; }
.post-content h3 { font-size: 21px; margin: 36px 0 14px; }
.post-content p { margin: 0 0 22px; }
.post-content code { font-family: var(--fi-font-mono); background: var(--fi-slate-100); padding: 2px 6px; border-radius: 3px; font-size: 0.88em; }
.post-content pre { background: var(--fi-charcoal); color: var(--fi-slate-100); padding: 18px 20px; border-radius: var(--fi-radius); overflow-x: auto; font-size: 14px; }
.post-content table { width: 100%; border-collapse: collapse; margin: 0 0 28px; font-size: 15.5px; }
.post-content table th,
.post-content table td { border: 1px solid var(--fi-border); padding: 10px 14px; text-align: left; }
.post-content table th { background: var(--fi-slate-100); font-family: var(--fi-font-mono); font-size: 12.5px; text-transform: uppercase; letter-spacing: 0.05em; }
.post-content blockquote { border-left: 3px solid var(--fi-steel-700); margin: 0 0 22px; padding: 4px 0 4px 20px; color: var(--fi-slate-700); font-style: italic; }

/* ============ RELATED POSTS ============ */
.related-posts { max-width: var(--fi-wide-width); margin: 0 auto; padding: 0 24px 48px; }
.related-posts h2 { font-size: 22px; margin-bottom: 24px; }
.related-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
@media (max-width: 800px) { .related-grid { grid-template-columns: 1fr; } }

/* ============ TOOLS EMBED ============ */
.tool-embed { max-width: var(--fi-wide-width); margin: 40px auto; padding: 0 24px; }
.tool-embed-frame { position: relative; width: 100%; padding-bottom: 70%; height: 0; overflow: hidden; border-radius: var(--fi-radius); border: 1px solid var(--fi-border); background: var(--fi-white); }
.tool-embed-frame iframe { position: absolute; top: 0; left: 0; width: 100%; height: 100%; border: 0; display: block; }

/* ============ LEGACY SUPPORT ============ */
.post-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 32px; max-width: var(--fi-wide-width); margin: 0 auto; }
.post-card { display: flex; flex-direction: column; border: 1px solid var(--fi-border); border-radius: var(--fi-radius); overflow: hidden; background: var(--fi-bg); transition: border-color .15s ease, transform .15s ease; }
.post-card-body { padding: 20px 22px 24px; }
.post-card-image { aspect-ratio: 16 / 9; background: var(--fi-slate-100); overflow: hidden; }
.post-card-image img { width: 100%; height: 100%; object-fit: cover; }
.post-card-tag { font-family: var(--fi-font-mono); font-size: 11.5px; text-transform: uppercase; letter-spacing: 0.08em; color: var(--fi-steel-700); margin-bottom: 10px; display: inline-block; }
.post-card h3 { font-size: 18px; line-height: 1.35; margin: 0 0 8px; color: var(--fi-black); }
.post-card-link { color: inherit; text-decoration: none; }
.post-card p.excerpt { font-size: 14.5px; color: var(--fi-text-muted); margin: 0 0 14px; }
.post-card-meta { font-size: 13px; color: var(--fi-slate-500); display: flex; gap: 10px; }
.post-tags { display: flex; gap: 6px; flex-wrap: wrap; margin: 20px 0; }
.post-tags__label { font-family: var(--fi-font-mono); font-size: 11px; text-transform: uppercase; color: var(--fi-slate-500); margin-right: 6px; }
.tools-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; max-width: var(--fi-wide-width); margin: 0 auto; }
.cat-blue { color: var(--fi-accent); }