/**
 * Static FAQ pages — self-contained styles aligned with cad.thingraph.site.
 * New articles: copy an existing .html, update <title>, meta, JSON-LD, and <main>.
 */
:root {
  --font-sans: ui-sans-serif, system-ui, -apple-system, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  --bg-page: #f5f7fb;
  --bg-surface: #ffffff;
  --text-heading: #303133;
  --text-prose: #333333;
  --text-muted: #606266;
  --text-subtle: #6b7280;
  --border-color: #e5e7eb;
  --link-color: #315fb6;
  --link-hover-color: #1a6dff;
  --logo-accent-1: #1a6dff;
  --logo-accent-2: #c822ff;
  --shadow-card: 0 8px 24px rgba(15, 23, 42, 0.08);
  --radius-lg: 12px;
  --max-width: 800px;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

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

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

a {
  color: var(--link-color);
  text-decoration: none;
}

a:hover {
  color: var(--link-hover-color);
  text-decoration: underline;
}

/* ── Header ─────────────────────────────────────────────────────────────── */
.faq-header {
  background: var(--bg-surface);
  border-bottom: 1px solid var(--border-color);
  position: sticky;
  top: 0;
  z-index: 10;
}

.faq-header__inner {
  max-width: 960px;
  margin: 0 auto;
  padding: 14px 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
}

.faq-brand {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 1.25rem;
  font-weight: 400;
  color: var(--text-subtle);
  text-decoration: none;
}

.faq-brand:hover {
  color: var(--text-heading);
  text-decoration: none;
}

.faq-brand img {
  width: 32px;
  height: 32px;
}

.faq-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 6px 18px;
  list-style: none;
  margin: 0;
  padding: 0;
  font-size: 0.9rem;
}

.faq-nav a {
  color: var(--text-muted);
}

.faq-nav a[aria-current='page'] {
  color: var(--text-heading);
  font-weight: 600;
  text-decoration: none;
}

/* ── Layout ───────────────────────────────────────────────────────────────── */
.faq-wrap {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 24px 20px 48px;
}

.faq-card {
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-card);
  padding: 40px 48px;
  background-image: linear-gradient(90deg, var(--logo-accent-1), var(--logo-accent-2));
  background-size: 100% 3px;
  background-position: top;
  background-repeat: no-repeat;
}

@media (max-width: 768px) {
  .faq-card {
    padding: 24px 20px;
  }
}

/* ── Typography ───────────────────────────────────────────────────────────── */
.faq-breadcrumb {
  font-size: 0.875rem;
  color: var(--text-muted);
  margin: 0 0 20px;
}

.faq-breadcrumb ol {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 4px;
}

.faq-breadcrumb li:not(:last-child)::after {
  content: '›';
  margin-left: 4px;
  color: var(--text-subtle);
}

.faq-eyebrow {
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--logo-accent-1);
  margin: 0 0 8px;
}

.faq-card h1 {
  font-size: 1.75rem;
  font-weight: 600;
  color: var(--text-heading);
  line-height: 1.3;
  margin: 0 0 16px;
}

.faq-lead {
  font-size: 1.05rem;
  color: var(--text-muted);
  margin: 0 0 28px;
}

.faq-card h2 {
  font-size: 1.2rem;
  font-weight: 600;
  color: var(--text-heading);
  margin: 32px 0 12px;
  padding-top: 8px;
  border-top: 1px solid var(--border-color);
}

.faq-card h2:first-of-type {
  border-top: none;
  padding-top: 0;
  margin-top: 0;
}

.faq-card h3 {
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--text-heading);
  margin: 20px 0 8px;
}

.faq-card p,
.faq-card li {
  margin: 0 0 12px;
}

.faq-card ul,
.faq-card ol {
  margin: 0 0 16px;
  padding-left: 1.4rem;
}

.faq-card li {
  margin-bottom: 8px;
}

.faq-card code {
  font-size: 0.9em;
  background: #f3f4f6;
  padding: 2px 6px;
  border-radius: 4px;
}

.faq-note {
  background: #f8fafc;
  border-left: 3px solid var(--logo-accent-1);
  padding: 14px 16px;
  margin: 20px 0;
  font-size: 0.95rem;
  color: var(--text-muted);
}

.faq-note strong {
  color: var(--text-heading);
}

/* ── YouTube embed (16:9) ─────────────────────────────────────────────────── */
.faq-video {
  margin: 24px 0 28px;
}

.faq-video__embed {
  position: relative;
  width: 100%;
  aspect-ratio: 16 / 9;
  background: #0f172a;
  border-radius: 8px;
  overflow: hidden;
  border: 1px solid var(--border-color);
}

.faq-video__embed iframe {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  border: 0;
}

.faq-video figcaption {
  margin-top: 10px;
  font-size: 0.875rem;
  color: var(--text-muted);
  text-align: center;
}

/* ── Index: article list ──────────────────────────────────────────────────── */
.faq-section-title {
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--text-heading);
  margin: 28px 0 12px;
}

.faq-article-list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.faq-article-list li {
  margin: 0 0 10px;
  padding: 0;
}

.faq-article-list a {
  display: block;
  padding: 14px 16px;
  border: 1px solid var(--border-color);
  border-radius: 8px;
  background: #fafbfc;
  color: var(--text-heading);
  font-weight: 500;
  text-decoration: none;
  transition: border-color 0.15s, box-shadow 0.15s;
}

.faq-article-list a:hover {
  border-color: var(--logo-accent-1);
  box-shadow: 0 2px 8px rgba(26, 109, 255, 0.08);
  text-decoration: none;
  color: var(--link-hover-color);
}

.faq-article-list .faq-article-desc {
  display: block;
  font-size: 0.875rem;
  font-weight: 400;
  color: var(--text-muted);
  margin-top: 4px;
}

/* ── Related links ────────────────────────────────────────────────────────── */
.faq-related {
  margin-top: 36px;
  padding-top: 24px;
  border-top: 1px solid var(--border-color);
}

.faq-related h2 {
  border: none;
  margin-top: 0;
  padding-top: 0;
  font-size: 1rem;
}

.faq-related ul {
  list-style: none;
  padding: 0;
  margin: 0;
}

.faq-related li {
  margin-bottom: 8px;
}

/* ── Footer ───────────────────────────────────────────────────────────────── */
.faq-footer {
  max-width: 960px;
  margin: 0 auto;
  padding: 24px 20px 40px;
  text-align: center;
  font-size: 0.85rem;
  color: var(--text-muted);
  border-top: 1px solid var(--border-color);
}

.faq-footer nav {
  margin-bottom: 12px;
}

.faq-footer nav a {
  margin: 0 10px;
}