/* =========================================================================
   Detronyx — main.css
   Brand: brand_v1.md (IBM Plex Mono + Inter Variable, dark navy backbone)
   Stack: vanilla CSS, mobile-first, no framework, CSS variables, WCAG 2.1 AA
   Layout: single-page landing rendered from detronyx_landing_copy_v3.1.md
   ========================================================================= */

/* -------------------------------------------------------------------------
   1. Design tokens — palette, typography, spacing, radius, shadow
   ------------------------------------------------------------------------- */
:root {
  /* Palette — navy backbone */
  --navy-900: #080D1C;          /* page background */
  --navy-800: #0E1527;          /* card backgrounds */
  --navy-700: #162034;          /* dividers, subtle borders */
  --navy-600: #1E2D44;          /* hover bg on dark surfaces */
  --ground-illustration: #0B1220; /* hero canvas, OG, logo backplate */

  /* Palette — light surfaces (rare on this page) */
  --surface-50: #F8FAFC;
  --surface-100: #EEF2F8;
  --surface-200: #DDE4F0;

  /* Palette — primary blue (UI side, AA contrast) */
  --blue-400: #93C5FD;          /* disabled state on dark */
  --blue-500: #3B82F6;          /* link, focus ring, accent */
  --blue-600: #2563EB;          /* primary CTA fill, AA on white text */
  --blue-700: #1D4ED8;          /* CTA hover */
  --blue-800: #1E40AF;          /* CTA active */
  --accent-illustration: #1D6AFF; /* hero/logo/OG illustration accent only */

  /* Palette — feedback states */
  --success-500: #16A34A;
  --warning-500: #D97706;
  --error-500: #DC2626;
  --info-500: #0EA5E9;

  /* Text on dark (primary surface) */
  --text-primary: #F0F4FF;      /* AAA on navy-900 */
  --text-secondary: #94A3B8;    /* AAA on navy-900 */
  --text-tertiary: #64748B;     /* AA on navy-900 (≥14 px) */
  --text-disabled: #3F4E63;     /* decorative only */

  /* Text on light (rare) */
  --text-on-light: #0F172A;
  --text-on-light-sec: #334155;
  --text-on-light-ter: #64748B;

  /* Typography stacks */
  --font-sans: 'Inter', system-ui, -apple-system, 'Segoe UI', 'Helvetica Neue',
               'Helvetica', 'Arial', sans-serif;
  --font-mono: 'IBM Plex Mono', 'JetBrains Mono', 'Fira Code', 'Cascadia Code',
               ui-monospace, 'SFMono-Regular', 'Menlo', 'Consolas', monospace;

  /* Spacing scale (4 px base) */
  --space-0: 0;
  --space-1: 0.25rem;   /* 4 px */
  --space-2: 0.5rem;    /* 8 px */
  --space-3: 0.75rem;   /* 12 px */
  --space-4: 1rem;      /* 16 px */
  --space-6: 1.5rem;    /* 24 px */
  --space-8: 2rem;      /* 32 px */
  --space-12: 3rem;     /* 48 px */
  --space-16: 4rem;     /* 64 px */
  --space-24: 6rem;     /* 96 px */
  --space-32: 8rem;     /* 128 px */

  /* Border radius */
  --radius-0: 0;
  --radius-1: 2px;     /* buttons, badge pills */
  --radius-2: 4px;     /* cards, code blocks, feature tiles */
  --radius-3: 8px;     /* modals, drawer panels, form inputs */
  --radius-4: 12px;    /* large overlay panels (rare) */

  /* Shadows (used sparingly on dark) */
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.4);
  --shadow-md: 0 4px 12px -2px rgba(0, 0, 0, 0.5),
               0 2px 4px -1px rgba(0, 0, 0, 0.3);
  --shadow-lg: 0 16px 48px -8px rgba(0, 0, 0, 0.7),
               0 4px 12px -2px rgba(0, 0, 0, 0.4);

  /* Layout */
  --max-content: 72rem;       /* 1152 px */
  --max-text:    44rem;       /* 704 px — comfortable measure for body copy */
  --header-height: 64px;

  /* Tell UA we are dark-only — adjusts default form-control colors */
  color-scheme: dark;
}

/* -------------------------------------------------------------------------
   2. Reset & base
   ------------------------------------------------------------------------- */
*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: var(--header-height);
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

body {
  margin: 0;
  background: var(--navy-900);
  color: var(--text-primary);
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.65;
  font-weight: 400;
  font-feature-settings: 'ss01', 'cv11';
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
}

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

a {
  color: var(--blue-500);
  text-decoration-color: rgba(59, 130, 246, 0.4);
  text-underline-offset: 0.15em;
  transition: color 150ms ease;
}
a:hover { color: var(--blue-400); }
a:focus-visible {
  outline: none;
  box-shadow: 0 0 0 2px var(--navy-900), 0 0 0 4px var(--blue-500);
  border-radius: var(--radius-1);
}

/* Skip-link */
.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  background: var(--blue-600);
  color: var(--text-primary);
  padding: var(--space-3) var(--space-4);
  z-index: 1000;
  font-weight: 600;
  border-radius: var(--radius-1);
}
.skip-link:focus {
  left: var(--space-2);
  top: var(--space-2);
}

/* -------------------------------------------------------------------------
   3. Typography — heading scale, body scale, special styles
   ------------------------------------------------------------------------- */
h1, h2, h3, h4, h5, h6 {
  margin: 0 0 var(--space-4) 0;
  color: var(--text-primary);
  font-weight: 700;
  line-height: 1.15;
  letter-spacing: -0.025em;
}

h1 {
  font-size: clamp(2.25rem, 4.5vw, 3.5rem); /* 36 px → 56 px */
  line-height: 1.1;
  letter-spacing: -0.03em;
  font-weight: 700;
}
h2 {
  font-size: clamp(1.75rem, 3.2vw, 2.5rem); /* 28 px → 40 px */
  line-height: 1.15;
  letter-spacing: -0.025em;
  font-weight: 700;
}
h3 {
  font-size: clamp(1.375rem, 2.4vw, 1.875rem); /* 22 px → 30 px */
  line-height: 1.2;
  letter-spacing: -0.02em;
  font-weight: 600;
}
h4 {
  font-size: clamp(1.125rem, 1.8vw, 1.375rem); /* 18 px → 22 px */
  line-height: 1.3;
  letter-spacing: -0.015em;
  font-weight: 600;
}
h5 {
  font-size: 1.125rem;
  line-height: 1.4;
  font-weight: 600;
  letter-spacing: -0.01em;
}
h6 {
  font-size: 0.875rem;
  line-height: 1.5;
  font-weight: 600;
  letter-spacing: 0;
}

p { margin: 0 0 var(--space-4) 0; }
p:last-child { margin-bottom: 0; }

ul, ol {
  margin: 0 0 var(--space-4) 0;
  padding-left: 1.25rem;
}
li { margin-bottom: var(--space-2); }

strong, b { color: var(--text-primary); font-weight: 600; }
em, i     { color: var(--text-primary); font-style: italic; }

small { font-size: 0.875rem; color: var(--text-secondary); }

/* Eyebrow text — monospace, small-caps effect */
.eyebrow {
  font-family: var(--font-mono);
  font-size: 0.6875rem;     /* 11 px */
  font-weight: 500;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--blue-500);
  margin-bottom: var(--space-3);
  display: inline-block;
}

/* Inline code */
code:not(pre code) {
  font-family: var(--font-mono);
  font-size: 0.875em;
  background: var(--navy-700);
  border: 1px solid var(--navy-600);
  border-radius: 3px;
  padding: 1px 5px;
  color: var(--blue-400);
  word-break: break-word;
}

/* Code block */
pre {
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  line-height: 1.65;
  background: var(--navy-800);
  border: 1px solid var(--navy-700);
  border-radius: var(--radius-2);
  padding: var(--space-6) var(--space-8);
  overflow-x: auto;
  tab-size: 4;
  margin: 0 0 var(--space-6) 0;
}
pre code { background: transparent; border: none; padding: 0; color: var(--text-primary); }

blockquote {
  margin: var(--space-6) 0;
  padding: var(--space-4) var(--space-6);
  border-left: 3px solid var(--blue-500);
  background: var(--navy-800);
  color: var(--text-primary);
  font-size: 1.0625rem;
  border-radius: 0 var(--radius-2) var(--radius-2) 0;
}
blockquote p { margin-bottom: var(--space-2); }
blockquote p:last-child { margin-bottom: 0; }

hr {
  border: 0;
  border-top: 1px solid var(--navy-700);
  margin: var(--space-12) 0;
}

::selection {
  background: var(--blue-600);
  color: var(--text-primary);
}

/* -------------------------------------------------------------------------
   4. Layout — container, sections
   ------------------------------------------------------------------------- */
.container {
  width: 100%;
  max-width: var(--max-content);
  margin-inline: auto;
  padding-inline: var(--space-4);
}
@media (min-width: 768px) {
  .container { padding-inline: var(--space-8); }
}

.container--narrow {
  max-width: var(--max-text);
}

section {
  padding-block: var(--space-12);
}
@media (min-width: 768px) {
  section { padding-block: var(--space-16); }
}
@media (min-width: 1024px) {
  section { padding-block: var(--space-24); }
}

.section-eyebrow {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--text-secondary);
  margin-bottom: var(--space-3);
}

/* -------------------------------------------------------------------------
   5. Header / nav
   ------------------------------------------------------------------------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  height: var(--header-height);
  background: rgba(8, 13, 28, 0.85);
  backdrop-filter: saturate(160%) blur(8px);
  -webkit-backdrop-filter: saturate(160%) blur(8px);
  border-bottom: 1px solid var(--navy-700);
}

.site-header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
  max-width: var(--max-content);
  margin-inline: auto;
  padding-inline: var(--space-4);
}
@media (min-width: 768px) {
  .site-header__inner { padding-inline: var(--space-8); }
}

.brand-link {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  text-decoration: none;
  color: var(--text-primary);
  font-family: var(--font-mono);
  font-weight: 600;
  font-size: 1rem;
  letter-spacing: 0.04em;
}
.brand-link:hover { color: var(--text-primary); }
.brand-link img { height: 28px; width: auto; }

.nav-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  background: transparent;
  border: 1px solid var(--navy-700);
  border-radius: var(--radius-1);
  color: var(--text-primary);
  cursor: pointer;
}
.nav-toggle:hover { background: var(--navy-800); }
.nav-toggle:focus-visible {
  outline: 2px solid var(--blue-500);
  outline-offset: 2px;
}
@media (min-width: 1024px) {
  .nav-toggle { display: none; }
}
.nav-toggle__icon { width: 20px; height: 2px; background: currentColor; position: relative; }
.nav-toggle__icon::before,
.nav-toggle__icon::after {
  content: '';
  position: absolute;
  left: 0;
  width: 100%;
  height: 2px;
  background: currentColor;
}
.nav-toggle__icon::before { top: -6px; }
.nav-toggle__icon::after  { top:  6px; }

.site-nav {
  display: none;
}
@media (min-width: 1024px) {
  .site-nav { display: block; }
  .site-nav__list {
    display: flex;
    align-items: center;
    gap: var(--space-6);
    list-style: none;
    margin: 0;
    padding: 0;
  }
  .site-nav__list a {
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.9375rem;
    font-weight: 500;
  }
  .site-nav__list a:hover { color: var(--text-primary); }
}

/* Mobile nav (open state) */
.site-nav.is-open {
  display: block;
  position: fixed;
  inset: var(--header-height) 0 0 0;
  background: var(--navy-900);
  z-index: 99;
  padding: var(--space-8) var(--space-4);
  overflow-y: auto;
}
.site-nav.is-open .site-nav__list {
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
  list-style: none;
  margin: 0;
  padding: 0;
}
.site-nav.is-open .site-nav__list a {
  display: block;
  padding: var(--space-3) var(--space-2);
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--text-primary);
  text-decoration: none;
  border-bottom: 1px solid var(--navy-700);
}

/* -------------------------------------------------------------------------
   6. Buttons
   ------------------------------------------------------------------------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  padding: 0.875rem 1.25rem;
  font-family: var(--font-sans);
  font-size: 0.9375rem;
  font-weight: 600;
  line-height: 1;
  text-decoration: none;
  border: 1px solid transparent;
  border-radius: var(--radius-1);
  cursor: pointer;
  transition: background-color 150ms ease, border-color 150ms ease, color 150ms ease;
  white-space: nowrap;
}
.btn:focus-visible {
  outline: none;
  box-shadow: 0 0 0 2px var(--navy-900), 0 0 0 4px var(--blue-500);
}

.btn--primary {
  background: var(--blue-600);
  color: var(--text-primary);
}
.btn--primary:hover  { background: var(--blue-700); color: var(--text-primary); }
.btn--primary:active { background: var(--blue-800); color: var(--text-primary); }
.btn--primary:disabled {
  background: var(--blue-400);
  color: var(--navy-700);
  cursor: not-allowed;
}

.btn--secondary {
  background: transparent;
  color: var(--text-primary);
  border-color: rgba(240, 244, 255, 0.3);
}
.btn--secondary:hover {
  background: var(--navy-800);
  border-color: rgba(240, 244, 255, 0.6);
  color: var(--text-primary);
}

.btn--ghost {
  background: transparent;
  color: var(--blue-500);
  padding: 0.625rem 0.75rem;
}
.btn--ghost:hover { color: var(--blue-400); }

.btn-row {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-3);
  margin-top: var(--space-6);
}

/* -------------------------------------------------------------------------
   7. Hero
   ------------------------------------------------------------------------- */
.hero {
  padding-block: var(--space-16);
  position: relative;
  background: var(--navy-900);
  overflow: hidden;
}
@media (min-width: 768px) {
  .hero { padding-block: var(--space-24); }
}

.hero__inner {
  max-width: var(--max-content);
  margin-inline: auto;
  padding-inline: var(--space-4);
  display: grid;
  gap: var(--space-12);
  grid-template-columns: 1fr;
  align-items: center;
}
@media (min-width: 768px) {
  .hero__inner { padding-inline: var(--space-8); }
}
@media (min-width: 1024px) {
  .hero__inner {
    grid-template-columns: 1.2fr 1fr;
    gap: var(--space-16);
  }
}

.hero__tagline {
  font-size: clamp(1.25rem, 2.4vw, 1.875rem);
  font-weight: 600;
  color: var(--text-primary);
  margin-block: var(--space-4) var(--space-6);
  letter-spacing: -0.02em;
  line-height: 1.25;
}

.hero__subhead {
  color: var(--text-secondary);
  font-size: 1.0625rem;
  line-height: 1.7;
  max-width: 38rem;
}

.hero__visual {
  display: flex;
  align-items: center;
  justify-content: center;
}
.hero__visual img {
  max-width: 100%;
  width: 100%;
  border-radius: var(--radius-2);
  border: 1px solid var(--navy-700);
}

/* Trust strip — monospace badges */
.trust-strip {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  margin-top: var(--space-8);
  padding-top: var(--space-6);
  border-top: 1px solid var(--navy-700);
  list-style: none;
  padding-left: 0;
}
.trust-strip li { margin: 0; }
.trust-strip__badge {
  display: inline-block;
  padding: 0.375rem 0.625rem;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 500;
  letter-spacing: 0.01em;
  color: var(--text-secondary);
  background: var(--navy-800);
  border: 1px solid var(--navy-700);
  border-radius: var(--radius-1);
}

/* -------------------------------------------------------------------------
   8. Cards
   ------------------------------------------------------------------------- */
.card {
  background: var(--navy-800);
  border: 1px solid var(--navy-700);
  border-radius: var(--radius-2);
  padding: var(--space-6);
  transition: border-color 150ms ease;
}
.card:hover { border-color: var(--blue-600); }

.card__eyebrow {
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--blue-500);
  margin-bottom: var(--space-3);
}
.card__title {
  margin-bottom: var(--space-3);
  color: var(--text-primary);
}
.card__body {
  color: var(--text-secondary);
  font-size: 0.9375rem;
  line-height: 1.65;
}
.card__body strong { color: var(--text-primary); }
.card__footer {
  margin-top: var(--space-4);
  padding-top: var(--space-4);
  border-top: 1px solid var(--navy-700);
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--text-tertiary);
}

/* Card grids */
.card-grid {
  display: grid;
  gap: var(--space-6);
  grid-template-columns: 1fr;
}
@media (min-width: 640px) {
  .card-grid--2 { grid-template-columns: repeat(2, 1fr); }
}
@media (min-width: 1024px) {
  .card-grid--3 { grid-template-columns: repeat(3, 1fr); }
  .card-grid--4 { grid-template-columns: repeat(4, 1fr); }
}

/* Section lead */
.section-lead {
  color: var(--text-secondary);
  font-size: 1.0625rem;
  line-height: 1.7;
  max-width: var(--max-text);
  margin-bottom: var(--space-8);
}
.section-lead strong { color: var(--text-primary); }

/* -------------------------------------------------------------------------
   9. Architecture / domains visualization
   ------------------------------------------------------------------------- */
.domain-card {
  background: var(--navy-800);
  border: 1px solid var(--navy-700);
  border-radius: var(--radius-2);
  padding: var(--space-6);
  position: relative;
}
.domain-card__index {
  position: absolute;
  top: var(--space-3);
  right: var(--space-4);
  font-family: var(--font-mono);
  font-size: 1.5rem;
  font-weight: 600;
  color: var(--blue-500);
  opacity: 0.4;
}
.domain-card__name {
  font-family: var(--font-mono);
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: var(--space-2);
  letter-spacing: 0.02em;
}
.domain-card__size {
  font-family: var(--font-mono);
  font-size: 0.875rem;
  color: var(--blue-400);
  margin-bottom: var(--space-4);
}
.domain-card__role {
  color: var(--text-secondary);
  font-size: 0.9375rem;
  margin-bottom: var(--space-4);
}
.domain-card__attag {
  background: var(--navy-700);
  border-left: 3px solid var(--blue-500);
  padding: var(--space-3) var(--space-4);
  border-radius: 0 var(--radius-2) var(--radius-2) 0;
  font-size: 0.875rem;
  color: var(--text-primary);
}
.domain-card__attag-label {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--blue-500);
  margin-bottom: var(--space-1);
}

/* Mechanism list */
.mech-list {
  display: grid;
  gap: var(--space-4);
  list-style: none;
  padding-left: 0;
  margin-top: var(--space-8);
}
@media (min-width: 768px) {
  .mech-list { grid-template-columns: repeat(2, 1fr); }
}
.mech-list li {
  background: var(--navy-800);
  border: 1px solid var(--navy-700);
  border-radius: var(--radius-2);
  padding: var(--space-4) var(--space-6);
  margin-bottom: 0;
}
.mech-list strong {
  display: block;
  margin-bottom: var(--space-1);
  color: var(--text-primary);
}
.mech-list em {
  display: block;
  margin-top: var(--space-2);
  font-style: normal;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--blue-500);
  letter-spacing: 0.04em;
}

/* -------------------------------------------------------------------------
   10. Tables (tier'd benefits, etc.)
   ------------------------------------------------------------------------- */
.table-wrap {
  overflow-x: auto;
  margin: var(--space-6) 0;
  border: 1px solid var(--navy-700);
  border-radius: var(--radius-2);
}
table {
  width: 100%;
  min-width: 600px;
  border-collapse: collapse;
  font-size: 0.9375rem;
}
thead {
  background: var(--navy-800);
}
th, td {
  text-align: left;
  padding: var(--space-3) var(--space-4);
  border-bottom: 1px solid var(--navy-700);
  vertical-align: top;
  color: var(--text-secondary);
}
th {
  font-weight: 600;
  color: var(--text-primary);
  font-size: 0.875rem;
  font-family: var(--font-mono);
  text-transform: uppercase;
  letter-spacing: 0.06em;
}
tr:last-child td { border-bottom: 0; }
td strong { color: var(--text-primary); }

/* -------------------------------------------------------------------------
   11. Forms
   ------------------------------------------------------------------------- */
.form {
  display: grid;
  gap: var(--space-5);
  max-width: 38rem;
}

.form__group {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.form__label {
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--text-secondary);
}
.form__label--required::after {
  content: ' *';
  color: var(--blue-500);
}

.form__input,
.form__select,
.form__textarea {
  display: block;
  width: 100%;
  padding: 0.625rem 0.875rem;
  font-family: var(--font-sans);
  font-size: 0.9375rem;
  background: var(--navy-800);
  color: var(--text-primary);
  border: 1px solid var(--navy-700);
  border-radius: var(--radius-3);
  transition: border-color 150ms ease, box-shadow 150ms ease;
}
.form__input::placeholder,
.form__textarea::placeholder { color: var(--text-disabled); }
.form__input:focus-visible,
.form__select:focus-visible,
.form__textarea:focus-visible {
  outline: 2px solid var(--blue-500);
  outline-offset: 2px;
  border-color: var(--blue-600);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.25);
}
/* Mouse focus retains a subtle ring without the AA outline */
.form__input:focus:not(:focus-visible),
.form__select:focus:not(:focus-visible),
.form__textarea:focus:not(:focus-visible) {
  outline: none;
  border-color: var(--blue-600);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.25);
}
.form__textarea { resize: vertical; min-height: 7rem; }

.form__hint {
  font-size: 0.8125rem;
  color: var(--text-tertiary);
  margin-top: var(--space-1);
}

/* -------------------------------------------------------------------------
   12. FAQ accordion (CSS-only via <details>)
   ------------------------------------------------------------------------- */
.faq-list { display: grid; gap: var(--space-3); }
.faq-item {
  background: var(--navy-800);
  border: 1px solid var(--navy-700);
  border-radius: var(--radius-2);
  padding: var(--space-4) var(--space-6);
}
.faq-item summary {
  cursor: pointer;
  font-weight: 600;
  color: var(--text-primary);
  font-size: 1rem;
  list-style: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: var(--space-3);
}
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary::after {
  content: '+';
  font-family: var(--font-mono);
  font-size: 1.25rem;
  color: var(--blue-500);
  transition: transform 150ms ease;
}
.faq-item[open] summary::after { content: '−'; }
.faq-item summary:focus-visible {
  outline: none;
  box-shadow: 0 0 0 2px var(--navy-900), 0 0 0 4px var(--blue-500);
  border-radius: var(--radius-1);
}
.faq-item__body {
  margin-top: var(--space-3);
  color: var(--text-secondary);
  font-size: 0.9375rem;
  line-height: 1.7;
}
.faq-item__body p { margin-bottom: var(--space-2); }
.faq-item__body p:last-child { margin-bottom: 0; }

/* -------------------------------------------------------------------------
   13. Footer
   ------------------------------------------------------------------------- */
.site-footer {
  background: var(--navy-800);
  border-top: 1px solid var(--navy-700);
  padding-block: var(--space-12) var(--space-8);
  color: var(--text-secondary);
  font-size: 0.9375rem;
}

.site-footer__inner {
  max-width: var(--max-content);
  margin-inline: auto;
  padding-inline: var(--space-4);
}
@media (min-width: 768px) {
  .site-footer__inner { padding-inline: var(--space-8); }
}

.footer-grid {
  display: grid;
  gap: var(--space-8);
  grid-template-columns: 1fr;
}
@media (min-width: 768px) {
  .footer-grid { grid-template-columns: repeat(3, 1fr); }
}

.footer-col h6 {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--blue-500);
  margin-bottom: var(--space-3);
}
.footer-col ul {
  list-style: none;
  padding: 0;
  margin: 0;
}
.footer-col li { margin-bottom: var(--space-2); }
.footer-col a {
  color: var(--text-secondary);
  text-decoration: none;
}
.footer-col a:hover { color: var(--text-primary); }

.footer-baseline {
  margin-top: var(--space-8);
  padding-top: var(--space-6);
  border-top: 1px solid var(--navy-700);
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: var(--space-3);
  font-size: 0.875rem;
  color: var(--text-tertiary);
}
.footer-strapline {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--text-secondary);
}

/* -------------------------------------------------------------------------
   14. Utilities
   ------------------------------------------------------------------------- */
.visually-hidden {
  position: absolute !important;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}
.text-mono    { font-family: var(--font-mono); }
.text-mute    { color: var(--text-secondary); }
.text-accent  { color: var(--blue-500); }
.text-tertiary { color: var(--text-tertiary); }

/* Margin-top utilities (replace inline style="margin-top: var(--space-N)") */
.mt-1  { margin-top: var(--space-1); }
.mt-2  { margin-top: var(--space-2); }
.mt-3  { margin-top: var(--space-3); }
.mt-4  { margin-top: var(--space-4); }
.mt-6  { margin-top: var(--space-6); }
.mt-8  { margin-top: var(--space-8); }
.mt-12 { margin-top: var(--space-12); }

/* Tight reset for nested lists in callout */
.list-tight { margin: var(--space-2) 0 0 0; }

.callout {
  border-left: 3px solid var(--blue-500);
  background: var(--navy-800);
  padding: var(--space-4) var(--space-6);
  border-radius: 0 var(--radius-2) var(--radius-2) 0;
  margin: var(--space-6) 0;
}
.callout strong { color: var(--text-primary); }

.tag-ipfence {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  padding: 1px 5px;
  background: var(--navy-700);
  color: var(--blue-400);
  border-radius: 3px;
  letter-spacing: 0.04em;
  margin-left: var(--space-1);
}

/* -------------------------------------------------------------------------
   15. Print
   ------------------------------------------------------------------------- */
@media print {
  :root { --navy-900: #ffffff; --navy-800: #f7f8fb; --navy-700: #d8dde6; }
  body { background: #ffffff; color: #0F172A; }
  .site-header, .site-nav, .nav-toggle { display: none; }
  a { color: #0F172A; text-decoration: underline; }
  section { padding-block: var(--space-8); page-break-inside: avoid; }
  .hero__visual, .trust-strip { display: none; }
  .card, .domain-card, .faq-item, blockquote { background: #f7f8fb; border: 1px solid #d8dde6; }
}