/* ==========================================================================
   NextEra Blog — blog.css
   Blue brand system (_context/brand-guidelines.md), typography matched to the
   main NextEra site (Albert Sans / Inter body, Manrope display). Mobile-first,
   68ch reading measure, light + dark via prefers-color-scheme.
   Every class is bg- (blog) prefixed so nothing collides if a snippet of this
   sheet ever ends up inlined next to page styles.
   ========================================================================== */

:root {
  /* brand constants (same in both themes) */
  --bg-accent:     #4A90FF;   /* website accent blue */
  --bg-accent-2:   #2FAAFF;   /* wordmark / label blue */
  --bg-accent-lt:  #70BFFF;   /* gradient end */
  --bg-cta:        #3D7DFF;   /* buttons */
  --bg-dark:       #060C18;   /* site dark background */
  --bg-dark-card:  #0D1B2E;
  --bg-glow:       #0F2540;

  /* light theme (default) */
  --bg-page:       #FFFFFF;
  --bg-page-soft:  #F5F8FC;
  --bg-ink:        #1A1A2E;
  --bg-muted:      #5A6577;
  --bg-faint:      #8A94A6;
  --bg-line:       rgba(26, 26, 46, 0.10);
  --bg-card:       #FFFFFF;
  --bg-card-line:  rgba(26, 26, 46, 0.08);
  --bg-card-shadow: 0 1px 2px rgba(15, 37, 64, 0.06), 0 12px 32px -16px rgba(15, 37, 64, 0.18);
  --bg-card-shadow-hover: 0 2px 4px rgba(15, 37, 64, 0.08), 0 20px 44px -16px rgba(15, 37, 64, 0.26);
  --bg-code-bg:    #0D1B2E;
  --bg-code-ink:   #9CCBFF;
  --bg-quote-bg:   rgba(74, 144, 255, 0.06);
  --bg-chip-bg:    rgba(26, 26, 46, 0.05);
  --bg-chip-ink:   #3D4657;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg-page:       #060C18;
    --bg-page-soft:  #0A1424;
    --bg-ink:        #E8EEF7;
    --bg-muted:      #9BA8B9;
    --bg-faint:      #6E7E93;
    --bg-line:       rgba(255, 255, 255, 0.10);
    --bg-card:       #0D1B2E;
    --bg-card-line:  rgba(255, 255, 255, 0.08);
    --bg-card-shadow: 0 1px 2px rgba(0, 0, 0, 0.4), 0 16px 40px -20px rgba(0, 0, 0, 0.6);
    --bg-card-shadow-hover: 0 2px 4px rgba(0, 0, 0, 0.5), 0 24px 52px -20px rgba(0, 0, 0, 0.7);
    --bg-code-bg:    #0A1424;
    --bg-code-ink:   #9CCBFF;
    --bg-quote-bg:   rgba(74, 144, 255, 0.10);
    --bg-chip-bg:    rgba(255, 255, 255, 0.07);
    --bg-chip-ink:   #C4CFDE;
  }
}

* { margin: 0; padding: 0; box-sizing: border-box; -webkit-tap-highlight-color: transparent; }
html { scroll-behavior: smooth; }
body {
  font-family: 'Albert Sans', 'Inter', system-ui, -apple-system, sans-serif;
  background: var(--bg-page);
  color: var(--bg-ink);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}
img { max-width: 100%; display: block; }
a { color: inherit; }

/* ------------------------------------------------------------------ */
/* Top bar — dark in both themes, matches the main site's band         */
/* ------------------------------------------------------------------ */

.bg-topbar {
  background: var(--bg-dark);
  background-image: radial-gradient(120% 160% at 50% -40%, var(--bg-glow) 0%, var(--bg-dark) 62%);
  border-bottom: 1px solid rgba(255, 255, 255, 0.07);
}
.bg-topbar-inner {
  max-width: 1080px;
  margin: 0 auto;
  padding: 16px 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}
.bg-brand { display: inline-flex; align-items: center; gap: 10px; text-decoration: none; }
.bg-mark { width: 26px; height: 26px; object-fit: contain; }
.bg-word {
  font-family: 'Manrope', 'Albert Sans', sans-serif;
  font-weight: 800;
  font-size: 17px;
  letter-spacing: -0.01em;
  color: #FFFFFF;
}
.bg-word .bg-next { color: var(--bg-accent); }
.bg-nav { display: flex; align-items: center; gap: 2px; }
.bg-nav-link {
  font-size: 14px;
  font-weight: 500;
  letter-spacing: -0.01em;
  color: rgba(255, 255, 255, 0.85);
  text-decoration: none;
  padding: 8px 12px;
  border-radius: 8px;
  transition: color 220ms ease;
}
.bg-nav-link:hover { color: var(--bg-accent); }
.bg-nav-link.is-active { color: var(--bg-accent-lt); }
.bg-nav-cta {
  margin-left: 8px;
  padding: 9px 16px;
  background: linear-gradient(135deg, #2FAAFF 0%, #4A90FF 55%, #6B5BFF 100%);
  color: #FFFFFF;
  border-radius: 999px;
  font-size: 13.5px;
  font-weight: 600;
  letter-spacing: -0.01em;
  text-decoration: none;
  white-space: nowrap;
  box-shadow:
    inset 0 0 0 1px rgba(255, 255, 255, 0.14),
    0 8px 24px -8px rgba(74, 144, 255, 0.6);
  transition: transform 200ms cubic-bezier(.2, .9, .3, 1.1), box-shadow 200ms ease;
}
.bg-nav-cta:hover {
  transform: translateY(-1px);
  box-shadow:
    inset 0 0 0 1px rgba(255, 255, 255, 0.20),
    0 14px 32px -8px rgba(74, 144, 255, 0.75);
}
/* On small phones the link row yields to brand + CTA */
@media (max-width: 560px) {
  .bg-nav-link { display: none; }
  .bg-nav-link.is-active { display: inline-block; }
}

/* ------------------------------------------------------------------ */
/* Index hero band                                                     */
/* ------------------------------------------------------------------ */

.bg-hero {
  background: var(--bg-dark);
  background-image: radial-gradient(90% 130% at 50% -10%, var(--bg-glow) 0%, var(--bg-dark) 68%);
  color: #FFFFFF;
  padding: 56px 0 60px;
}
.bg-hero-inner { max-width: 720px; margin: 0 auto; padding: 0 20px; text-align: center; }
.bg-hero h1 {
  font-family: 'Manrope', 'Albert Sans', sans-serif;
  font-weight: 800;
  font-size: clamp(32px, 6vw, 48px);
  line-height: 1.08;
  letter-spacing: -0.02em;
  margin: 10px 0 14px;
  background: linear-gradient(100deg, #FFFFFF 30%, var(--bg-accent-lt) 100%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}
.bg-hero .bg-lede { color: #9BA8B9; font-size: 16.5px; max-width: 54ch; margin: 0 auto; }

.bg-eyebrow {
  font-size: 12.5px;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--bg-accent-2);
}

/* ------------------------------------------------------------------ */
/* Main column                                                         */
/* ------------------------------------------------------------------ */

.bg-main { max-width: 720px; margin: 0 auto; padding: 40px 20px 72px; }
.bg-main--index { max-width: 1080px; padding-top: 32px; }
.bg-lede { color: var(--bg-muted); font-size: 16.5px; }

/* ------------------------------------------------------------------ */
/* Filter chips                                                        */
/* ------------------------------------------------------------------ */

.bg-chips {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 0 0 24px;
  position: relative;
  z-index: 2;
}
.bg-chip {
  font-family: inherit;
  font-size: 13px;
  font-weight: 600;
  letter-spacing: -0.005em;
  color: var(--bg-chip-ink);
  background: var(--bg-card);
  border: 1px solid var(--bg-card-line);
  box-shadow: var(--bg-card-shadow);
  padding: 8px 15px;
  border-radius: 999px;
  cursor: pointer;
  transition: color 180ms ease, background 180ms ease, border-color 180ms ease, transform 180ms ease;
}
.bg-chip:hover { color: var(--bg-accent); border-color: rgba(74, 144, 255, 0.45); }
.bg-chip.is-on {
  color: #FFFFFF;
  background: linear-gradient(135deg, #2FAAFF 0%, #4A90FF 70%);
  border-color: transparent;
  box-shadow: 0 8px 20px -8px rgba(74, 144, 255, 0.55);
}

/* ------------------------------------------------------------------ */
/* Card grid                                                           */
/* ------------------------------------------------------------------ */

.bg-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(290px, 1fr));
  gap: 22px;
}
.bg-card {
  display: flex;
  flex-direction: column;
  background: var(--bg-card);
  border: 1px solid var(--bg-card-line);
  border-radius: 16px;
  overflow: hidden;
  text-decoration: none;
  box-shadow: var(--bg-card-shadow);
  transition: transform 220ms cubic-bezier(.2, .9, .3, 1.05), box-shadow 220ms ease, border-color 220ms ease;
}
.bg-card:hover {
  transform: translateY(-3px);
  box-shadow: var(--bg-card-shadow-hover);
  border-color: rgba(74, 144, 255, 0.35);
}
.bg-card-media {
  aspect-ratio: 1200 / 630;
  background: var(--bg-page-soft);
  overflow: hidden;
}
.bg-card-media img { width: 100%; height: 100%; object-fit: cover; }
.bg-card-media--empty {
  display: grid;
  place-items: center;
  background: var(--bg-dark);
  background-image: radial-gradient(110% 150% at 50% -20%, var(--bg-glow) 0%, var(--bg-dark) 70%);
}
.bg-card-media--empty span {
  font-family: 'Manrope', 'Albert Sans', sans-serif;
  font-weight: 800;
  font-size: 22px;
  letter-spacing: -0.01em;
  color: var(--bg-accent);
}
.bg-card-media--empty span b { color: #FFFFFF; font-weight: 800; }
.bg-card-body { display: flex; flex-direction: column; gap: 8px; padding: 18px 20px 20px; flex: 1; }
.bg-card-pillar {
  font-size: 11.5px;
  font-weight: 600;
  letter-spacing: 0.10em;
  text-transform: uppercase;
  color: var(--bg-accent-2);
}
.bg-card-title {
  font-family: 'Manrope', 'Albert Sans', sans-serif;
  font-weight: 800;
  font-size: 19px;
  line-height: 1.22;
  letter-spacing: -0.015em;
  color: var(--bg-ink);
}
.bg-card:hover .bg-card-title { color: var(--bg-accent); }
.bg-card-excerpt {
  font-size: 14.5px;
  color: var(--bg-muted);
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}
.bg-card-meta { margin-top: auto; padding-top: 6px; font-size: 13px; color: var(--bg-faint); }
.bg-dot { margin: 0 2px; color: var(--bg-faint); }

/* ------------------------------------------------------------------ */
/* Article                                                             */
/* ------------------------------------------------------------------ */

.bg-article { padding-top: 8px; }
.bg-article-head { padding: 24px 0 8px; }
.bg-article-head h1 {
  font-family: 'Manrope', 'Albert Sans', sans-serif;
  font-weight: 800;
  font-size: clamp(30px, 5.4vw, 42px);
  line-height: 1.12;
  letter-spacing: -0.02em;
  margin: 10px 0 16px;
}
.bg-byline {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 14px;
  color: var(--bg-muted);
  padding-bottom: 22px;
  border-bottom: 1px solid var(--bg-line);
}
.bg-author { font-weight: 600; color: var(--bg-ink); }
.bg-cover {
  margin: 26px 0 6px;
  border-radius: 16px;
  overflow: hidden;
  border: 1px solid var(--bg-card-line);
  box-shadow: var(--bg-card-shadow);
}
.bg-cover img { width: 100%; }

/* Prose — the reading measure */
.bg-prose {
  max-width: 68ch;
  margin-top: 26px;
  font-size: 17px;
}
.bg-prose > * + * { margin-top: 1.15em; }
.bg-prose h2 {
  font-family: 'Manrope', 'Albert Sans', sans-serif;
  font-weight: 800;
  font-size: 25px;
  line-height: 1.2;
  letter-spacing: -0.015em;
  margin-top: 1.9em;
}
.bg-prose h2.bp-h1 { font-size: 28px; }
.bg-prose h3 {
  font-weight: 700;
  font-size: 19px;
  line-height: 1.3;
  letter-spacing: -0.01em;
  margin-top: 1.6em;
}
.bg-prose p { color: var(--bg-ink); }
.bg-prose a { color: var(--bg-accent); text-decoration: underline; text-underline-offset: 3px; text-decoration-thickness: 1px; }
.bg-prose a:hover { color: var(--bg-cta); }
.bg-prose strong { font-weight: 700; }
.bg-prose ul, .bg-prose ol { padding-left: 1.35em; }
.bg-prose li { margin-top: 0.45em; }
.bg-prose li::marker { color: var(--bg-accent); font-weight: 700; }
.bg-prose blockquote {
  border-left: 3px solid var(--bg-accent);
  background: var(--bg-quote-bg);
  border-radius: 0 12px 12px 0;
  padding: 16px 20px;
  font-size: 18px;
  line-height: 1.55;
  font-weight: 500;
  color: var(--bg-ink);
}
.bg-prose hr { border: none; border-top: 1px solid var(--bg-line); margin: 2.2em auto; width: 120px; }
.bg-prose figure { margin: 1.8em 0; }
.bg-prose figure img {
  width: 100%;
  border-radius: 14px;
  border: 1px solid var(--bg-card-line);
  box-shadow: var(--bg-card-shadow);
}
.bg-prose figcaption {
  margin-top: 10px;
  font-size: 13.5px;
  color: var(--bg-faint);
  text-align: center;
}
.bg-prose pre {
  background: var(--bg-code-bg);
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: 12px;
  padding: 16px 18px;
  overflow-x: auto;
}
.bg-prose pre code {
  font-family: 'SF Mono', ui-monospace, Consolas, Menlo, monospace;
  font-size: 13.5px;
  line-height: 1.6;
  color: var(--bg-code-ink);
  background: none;
  padding: 0;
}
.bg-prose code {
  font-family: 'SF Mono', ui-monospace, Consolas, Menlo, monospace;
  font-size: 0.88em;
  background: var(--bg-chip-bg);
  border-radius: 5px;
  padding: 0.15em 0.4em;
}

/* 404 */
.bg-404 { text-align: center; padding: 48px 0 24px; }
.bg-404 h1 {
  font-family: 'Manrope', 'Albert Sans', sans-serif;
  font-weight: 800;
  font-size: clamp(28px, 5vw, 38px);
  letter-spacing: -0.02em;
  margin: 10px 0 12px;
}
.bg-404 .bg-lede { max-width: 44ch; margin: 0 auto 26px; }

/* ------------------------------------------------------------------ */
/* CTA block                                                           */
/* ------------------------------------------------------------------ */

.bg-cta-block {
  margin-top: 56px;
  background: var(--bg-dark);
  background-image: radial-gradient(110% 160% at 50% -30%, var(--bg-glow) 0%, var(--bg-dark) 70%);
  border: 1px solid rgba(74, 144, 255, 0.28);
  border-radius: 20px;
  padding: 36px 28px;
  text-align: center;
  color: #FFFFFF;
}
.bg-cta-eyebrow {
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--bg-accent-2);
}
.bg-cta-title {
  font-family: 'Manrope', 'Albert Sans', sans-serif;
  font-weight: 800;
  font-size: clamp(22px, 4vw, 28px);
  line-height: 1.16;
  letter-spacing: -0.015em;
  margin: 10px auto 10px;
  max-width: 24ch;
}
.bg-cta-body { color: #9BA8B9; font-size: 15px; max-width: 52ch; margin: 0 auto 22px; }
.bg-cta-btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 13px 26px;
  background: linear-gradient(135deg, #2FAAFF 0%, #3D7DFF 60%, #4A90FF 100%);
  color: #FFFFFF;
  border-radius: 999px;
  font-size: 15px;
  font-weight: 600;
  letter-spacing: -0.01em;
  text-decoration: none;
  box-shadow:
    inset 0 0 0 1px rgba(255, 255, 255, 0.16),
    0 10px 28px -8px rgba(61, 125, 255, 0.65);
  transition: transform 200ms cubic-bezier(.2, .9, .3, 1.1), box-shadow 200ms ease;
}
.bg-cta-btn:hover {
  transform: translateY(-1px);
  box-shadow:
    inset 0 0 0 1px rgba(255, 255, 255, 0.22),
    0 16px 36px -8px rgba(61, 125, 255, 0.8);
}

/* ------------------------------------------------------------------ */
/* Footer                                                              */
/* ------------------------------------------------------------------ */

.bg-footer {
  background: var(--bg-dark);
  color: rgba(255, 255, 255, 0.65);
  font-size: 13px;
  border-top: 1px solid rgba(255, 255, 255, 0.07);
}
.bg-footer-inner {
  max-width: 1080px;
  margin: 0 auto;
  padding: 26px 20px;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}
.bg-footer-nav { display: flex; flex-wrap: wrap; gap: 18px; }
.bg-footer-nav a { color: rgba(255, 255, 255, 0.85); text-decoration: none; transition: color 180ms ease; }
.bg-footer-nav a:hover { color: var(--bg-accent); }

/* ------------------------------------------------------------------ */
/* Wider screens                                                       */
/* ------------------------------------------------------------------ */

@media (min-width: 800px) {
  .bg-topbar-inner { padding: 18px 28px; }
  .bg-hero { padding: 76px 0 84px; }
  .bg-main { padding-top: 48px; }
  .bg-main--index { padding-top: 40px; }
  .bg-article-head { padding-top: 36px; }
  .bg-cta-block { padding: 44px 40px; }
}

@media (prefers-reduced-motion: reduce) {
  * { transition: none !important; }
  html { scroll-behavior: auto; }
}