/* ============================================================
   GUARDIAN GAS SOLUTIONS — site styles
   dark / chrome / sleek
   ============================================================ */

/* -- DESIGN TOKENS ---------------------------------------- */
:root {
  /* foundation */
  --near-black:   #0E0E10;
  --black:        #050507;
  --charcoal:     #1F2024;
  --charcoal-2:   #14151A;
  --charcoal-3:   #2A2B30;

  /* chrome */
  --silver-light: #E8E8E8;
  --silver-mid:   #9DA3A8;
  --silver-deep:  #6B7280;
  --silver-faint: #3F434B;

  /* accent */
  --royal:        #1E5BBF;
  --royal-2:      #2F6BD0;
  --royal-deep:   #154A9C;
  --cyan:         #8FD0F0;

  /* light surfaces */
  --paper:        #FAFAFB;
  --hairline:     rgba(255,255,255,0.08);
  --hairline-strong: rgba(255,255,255,0.16);

  /* type tokens */
  --font-display: 'Oswald', 'Arial Narrow', sans-serif;
  --font-body:    'Manrope', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-mono:    'JetBrains Mono', 'Courier New', monospace;

  /* spacing scale */
  --space-1: 0.5rem;
  --space-2: 1rem;
  --space-3: 1.5rem;
  --space-4: 2rem;
  --space-5: 3rem;
  --space-6: 4rem;
  --space-7: 6rem;
  --space-8: 8rem;

  /* layout */
  --container:    1200px;
  --container-wide: 1400px;
}

/* -- RESET ------------------------------------------------ */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

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

body {
  font-family: var(--font-body);
  font-weight: 400;
  font-size: 16px;
  line-height: 1.6;
  color: var(--silver-light);
  background: var(--near-black);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
  min-height: 100vh;
}

img { max-width: 100%; height: auto; display: block; }
a   { color: inherit; text-decoration: none; }
button { font-family: inherit; cursor: pointer; border: none; background: none; color: inherit; }

/* -- TYPE ------------------------------------------------- */
h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: 600;
  line-height: 1.05;
  letter-spacing: 0.02em;
  color: var(--silver-light);
  text-transform: uppercase;
}

h1 {
  font-size: clamp(2.5rem, 6vw, 5.5rem);
  font-weight: 700;
  letter-spacing: 0.01em;
}

h2 {
  font-size: clamp(2rem, 4vw, 3.5rem);
  letter-spacing: 0.03em;
}

h3 {
  font-size: clamp(1.25rem, 2vw, 1.75rem);
  letter-spacing: 0.05em;
}

h4 {
  font-size: 1rem;
  letter-spacing: 0.15em;
  color: var(--silver-mid);
  font-weight: 500;
}

p { color: var(--silver-mid); }
p strong { color: var(--silver-light); font-weight: 600; }

/* eyebrow — small monospaced label above section titles */
.eyebrow {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 500;
  letter-spacing: 0.25em;
  text-transform: uppercase;
  color: var(--royal-2);
  margin-bottom: var(--space-2);
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.eyebrow::before {
  content: "";
  width: 24px;
  height: 1px;
  background: var(--royal-2);
}

.eyebrow.centered {
  justify-content: center;
}
.eyebrow.centered::after {
  content: "";
  width: 24px;
  height: 1px;
  background: var(--royal-2);
}

/* mono = inline code-style text */
.mono { font-family: var(--font-mono); font-size: 0.875rem; letter-spacing: 0.02em; }

/* -- LAYOUT ----------------------------------------------- */
.container {
  width: 100%;
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 var(--space-3);
}

.container-wide {
  width: 100%;
  max-width: var(--container-wide);
  margin: 0 auto;
  padding: 0 var(--space-3);
}

section {
  padding: var(--space-7) 0;
  position: relative;
}

@media (max-width: 768px) {
  section { padding: var(--space-6) 0; }
}

/* -- BACKGROUND TEXTURES --------------------------------- */
.bg-scan {
  position: relative;
  overflow: hidden;
}
.bg-scan::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    repeating-linear-gradient(0deg,
      transparent 0,
      transparent 3px,
      rgba(255,255,255,0.012) 3px,
      rgba(255,255,255,0.012) 4px);
  pointer-events: none;
  z-index: 1;
}

.bg-grid {
  background-image:
    linear-gradient(to right, var(--hairline) 1px, transparent 1px),
    linear-gradient(to bottom, var(--hairline) 1px, transparent 1px);
  background-size: 60px 60px;
}

.bg-gradient-radial {
  background:
    radial-gradient(ellipse 80% 60% at 50% 0%,
      rgba(30, 91, 191, 0.12) 0%,
      transparent 50%),
    var(--near-black);
}

/* -- NAV -------------------------------------------------- */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  background: rgba(14, 14, 16, 0.85);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--hairline);
  transition: all 0.3s ease;
}

.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1rem var(--space-3);
  max-width: var(--container-wide);
  margin: 0 auto;
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.nav-logo img {
  height: 42px;
  width: auto;
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: 2.5rem;
  list-style: none;
}

.nav-menu a {
  font-family: var(--font-body);
  font-size: 0.875rem;
  font-weight: 500;
  letter-spacing: 0.05em;
  color: var(--silver-mid);
  text-transform: uppercase;
  transition: color 0.2s ease;
  position: relative;
  padding: 0.5rem 0;
}

.nav-menu a:hover, .nav-menu a.active {
  color: var(--silver-light);
}

.nav-menu a.active::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: var(--royal);
}

.nav-cta {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.625rem 1.25rem;
  background: var(--royal);
  color: var(--silver-light) !important;
  border-radius: 2px;
  font-weight: 600 !important;
  font-size: 0.8125rem !important;
  letter-spacing: 0.08em !important;
  transition: all 0.2s ease;
}

.nav-cta:hover {
  background: var(--royal-2);
  transform: translateY(-1px);
}

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  padding: 0.5rem;
}
.nav-toggle span {
  width: 24px; height: 2px; background: var(--silver-light);
  transition: all 0.3s ease;
}

@media (max-width: 900px) {
  .nav-menu { display: none; }
  .nav-menu.open {
    display: flex;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    flex-direction: column;
    background: var(--near-black);
    padding: 2rem;
    gap: 1.5rem;
    border-bottom: 1px solid var(--hairline);
  }
  .nav-toggle { display: flex; }
  .nav-toggle.open span:nth-child(1) { transform: rotate(45deg) translate(5px, 5px); }
  .nav-toggle.open span:nth-child(2) { opacity: 0; }
  .nav-toggle.open span:nth-child(3) { transform: rotate(-45deg) translate(5px, -5px); }
}

/* spacer so content doesn't go under fixed nav */
.nav-spacer { height: 74px; }

/* -- BUTTONS ---------------------------------------------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
  padding: 1rem 1.75rem;
  font-family: var(--font-body);
  font-size: 0.875rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  border-radius: 2px;
  transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
  cursor: pointer;
  border: 1px solid transparent;
  position: relative;
  overflow: hidden;
}

.btn-primary {
  background: var(--royal);
  color: var(--silver-light);
  border-color: var(--royal);
}
.btn-primary:hover {
  background: var(--royal-2);
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(30, 91, 191, 0.3);
}

.btn-ghost {
  background: transparent;
  color: var(--silver-light);
  border-color: var(--silver-deep);
}
.btn-ghost:hover {
  border-color: var(--silver-light);
  background: rgba(255,255,255,0.03);
}

.btn-arrow {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  transition: gap 0.2s ease;
}
.btn:hover .btn-arrow { gap: 0.75rem; }

/* -- HERO ------------------------------------------------- */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  position: relative;
  padding: var(--space-7) 0 var(--space-7);
  overflow: hidden;
}

.hero-grid-bg {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(to right, var(--hairline) 1px, transparent 1px),
    linear-gradient(to bottom, var(--hairline) 1px, transparent 1px);
  background-size: 80px 80px;
  mask-image: radial-gradient(ellipse 60% 60% at 50% 40%, black 30%, transparent 75%);
  -webkit-mask-image: radial-gradient(ellipse 60% 60% at 50% 40%, black 30%, transparent 75%);
}

.hero-glow {
  position: absolute;
  top: 20%; left: 50%;
  transform: translate(-50%, -50%);
  width: 800px;
  height: 800px;
  background: radial-gradient(circle,
    rgba(30, 91, 191, 0.18) 0%,
    rgba(30, 91, 191, 0.05) 30%,
    transparent 60%);
  pointer-events: none;
}

.hero-content {
  position: relative;
  z-index: 2;
  text-align: center;
  max-width: 900px;
  margin: 0 auto;
}

.hero-shield {
  width: 160px;
  height: 160px;
  margin: 0 auto var(--space-4);
  filter: drop-shadow(0 0 30px rgba(30, 91, 191, 0.4));
  animation: float 6s ease-in-out infinite;
}

@keyframes float {
  0%, 100% { transform: translateY(0); }
  50%      { transform: translateY(-8px); }
}

.hero h1 {
  margin-bottom: var(--space-3);
}

.hero h1 span.accent {
  color: var(--royal-2);
  display: block;
}

.hero-tagline {
  font-size: clamp(1.125rem, 1.5vw, 1.25rem);
  color: var(--silver-mid);
  max-width: 640px;
  margin: 0 auto var(--space-5);
  line-height: 1.6;
}

.hero-cta {
  display: flex;
  gap: 1rem;
  justify-content: center;
  flex-wrap: wrap;
}

.hero-meta {
  margin-top: var(--space-6);
  display: flex;
  justify-content: center;
  gap: 3rem;
  flex-wrap: wrap;
}

.hero-meta-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.25rem;
}

.hero-meta-label {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--silver-deep);
}

.hero-meta-value {
  font-family: var(--font-display);
  font-size: 1.5rem;
  font-weight: 600;
  color: var(--silver-light);
  letter-spacing: 0.02em;
}

/* -- SECTION HEADER PATTERN ------------------------------ */
.section-header {
  text-align: center;
  margin-bottom: var(--space-6);
  max-width: 720px;
  margin-left: auto;
  margin-right: auto;
}

.section-header.left {
  text-align: left;
  margin-left: 0;
}

.section-header.left .eyebrow {
  justify-content: flex-start;
}

.section-header p {
  margin-top: var(--space-2);
  font-size: 1.125rem;
  line-height: 1.6;
}

/* -- CARDS ------------------------------------------------ */
.card {
  background: var(--charcoal-2);
  border: 1px solid var(--hairline);
  padding: var(--space-4);
  border-radius: 4px;
  transition: all 0.3s ease;
  position: relative;
  overflow: hidden;
}

.card:hover {
  border-color: var(--hairline-strong);
  transform: translateY(-2px);
}

.card-icon {
  width: 48px;
  height: 48px;
  color: var(--royal-2);
  margin-bottom: var(--space-3);
}

.card-icon svg { width: 100%; height: 100%; }

.card h3 {
  font-size: 1.25rem;
  margin-bottom: var(--space-2);
  color: var(--silver-light);
}

.card p {
  font-size: 0.9375rem;
  color: var(--silver-mid);
  line-height: 1.6;
}

.card-link {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  margin-top: var(--space-3);
  color: var(--royal-2);
  font-size: 0.8125rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  transition: gap 0.2s ease;
}
.card:hover .card-link { gap: 0.75rem; }

/* highlighted card variant - has a subtle accent */
.card.featured {
  background: linear-gradient(180deg, rgba(30,91,191,0.08), transparent 60%), var(--charcoal-2);
  border-color: rgba(30, 91, 191, 0.25);
}

/* -- GRID UTILITIES --------------------------------------- */
.grid {
  display: grid;
  gap: var(--space-3);
}

.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }

@media (max-width: 900px) {
  .grid-3, .grid-4 { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 600px) {
  .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; }
}

/* -- STATS BAND ------------------------------------------- */
.stats-band {
  background: var(--black);
  border-top: 1px solid var(--hairline);
  border-bottom: 1px solid var(--hairline);
  padding: var(--space-5) 0;
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-3);
  text-align: center;
}

@media (max-width: 700px) {
  .stats-grid { grid-template-columns: repeat(2, 1fr); }
}

.stat-num {
  font-family: var(--font-display);
  font-size: clamp(2rem, 4vw, 3rem);
  font-weight: 700;
  color: var(--silver-light);
  letter-spacing: 0.02em;
  line-height: 1;
  margin-bottom: 0.5rem;
}

.stat-num .unit {
  color: var(--royal-2);
}

.stat-label {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--silver-deep);
}

/* -- FOOTER ----------------------------------------------- */
footer {
  background: var(--black);
  border-top: 1px solid var(--hairline);
  padding: var(--space-6) 0 var(--space-4);
  color: var(--silver-mid);
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.5fr 1fr 1fr 1fr;
  gap: var(--space-5);
  margin-bottom: var(--space-5);
}

@media (max-width: 900px) {
  .footer-grid { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 600px) {
  .footer-grid { grid-template-columns: 1fr; }
}

.footer-brand img {
  height: 48px;
  width: auto;
  margin-bottom: var(--space-2);
}

.footer-tagline {
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  color: var(--silver-deep);
  letter-spacing: 0.05em;
}

.footer-col h4 {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.2em;
  color: var(--silver-deep);
  margin-bottom: var(--space-3);
  text-transform: uppercase;
}

.footer-col ul { list-style: none; }
.footer-col li { margin-bottom: 0.75rem; font-size: 0.9375rem; }
.footer-col a:hover { color: var(--silver-light); }

.footer-bottom {
  border-top: 1px solid var(--hairline);
  padding-top: var(--space-3);
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 1rem;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--silver-deep);
  letter-spacing: 0.05em;
}

.footer-signoff {
  color: var(--silver-mid);
  font-style: italic;
}

/* -- FORM ------------------------------------------------- */
.form-group {
  margin-bottom: var(--space-3);
}

.form-label {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--silver-deep);
  margin-bottom: 0.5rem;
}

.form-input,
.form-textarea,
.form-select {
  width: 100%;
  background: var(--charcoal-2);
  border: 1px solid var(--hairline-strong);
  color: var(--silver-light);
  font-family: var(--font-body);
  font-size: 1rem;
  padding: 0.875rem 1rem;
  border-radius: 2px;
  transition: all 0.2s ease;
}

.form-input:focus,
.form-textarea:focus,
.form-select:focus {
  outline: none;
  border-color: var(--royal-2);
  background: var(--charcoal);
  box-shadow: 0 0 0 3px rgba(30, 91, 191, 0.15);
}

.form-textarea {
  min-height: 140px;
  resize: vertical;
  font-family: var(--font-body);
}

.form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-3);
}

@media (max-width: 600px) {
  .form-row { grid-template-columns: 1fr; }
}

.honeypot {
  position: absolute;
  left: -9999px;
  visibility: hidden;
}

/* -- UTILITIES ------------------------------------------- */
.text-center { text-align: center; }
.text-mono   { font-family: var(--font-mono); }
.text-accent { color: var(--royal-2); }
.text-silver { color: var(--silver-light); }

.divider-rule {
  height: 1px;
  background: var(--hairline);
  margin: var(--space-5) 0;
}

/* -- SCROLL-IN ANIMATIONS -------------------------------- */
.fade-up {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.8s ease, transform 0.8s ease;
}
.fade-up.visible {
  opacity: 1;
  transform: translateY(0);
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
  .fade-up { opacity: 1; transform: none; }
}

/* ============================================================
   INTERACTIVE COMPONENTS
   BTU calculator · Checklist · Accordion · etc.
   ============================================================ */

/* -- BTU CALCULATOR --------------------------------------- */
.btu-calc {
  background: var(--charcoal-2);
  border: 1px solid var(--hairline);
  border-radius: 6px;
  overflow: hidden;
  display: grid;
  grid-template-columns: 1.4fr 1fr;
}
@media (max-width: 900px) {
  .btu-calc { grid-template-columns: 1fr; }
}

.btu-calc-list {
  padding: var(--space-3);
  border-right: 1px solid var(--hairline);
  max-height: 540px;
  overflow-y: auto;
}
@media (max-width: 900px) {
  .btu-calc-list { border-right: none; border-bottom: 1px solid var(--hairline); max-height: none; }
}

.btu-calc-list::-webkit-scrollbar { width: 6px; }
.btu-calc-list::-webkit-scrollbar-track { background: var(--charcoal); }
.btu-calc-list::-webkit-scrollbar-thumb { background: var(--silver-faint); border-radius: 3px; }

.btu-calc-head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  padding-bottom: var(--space-2);
  margin-bottom: var(--space-2);
  border-bottom: 1px solid var(--hairline);
}
.btu-calc-head h3 {
  font-size: 1rem;
  letter-spacing: 0.1em;
  color: var(--silver-light);
  margin: 0;
}
.btu-calc-head .mono {
  color: var(--silver-deep);
  font-size: 0.7rem;
  letter-spacing: 0.2em;
}

.btu-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.75rem 0;
  border-bottom: 1px solid rgba(255,255,255,0.04);
  transition: background 0.2s ease;
}
.btu-row:last-child { border-bottom: none; }
.btu-row.active {
  background: linear-gradient(90deg, rgba(30,91,191,0.06), transparent);
}
.btu-row-label { flex: 1; min-width: 0; }
.btu-row-name {
  display: block;
  font-size: 0.9375rem;
  font-weight: 500;
  color: var(--silver-light);
  margin-bottom: 2px;
}
.btu-row-btu {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--silver-deep);
  letter-spacing: 0.05em;
}
.btu-row-qty {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  flex-shrink: 0;
}
.btu-qty-btn {
  width: 30px; height: 30px;
  border-radius: 4px;
  background: var(--charcoal);
  border: 1px solid var(--hairline-strong);
  color: var(--silver-light);
  font-size: 1.1rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.15s ease;
  display: flex; align-items: center; justify-content: center;
  padding: 0; line-height: 1;
}
.btu-qty-btn:hover { background: var(--royal); border-color: var(--royal); }
.btu-qty-btn:active { transform: scale(0.95); }
.btu-qty-val {
  font-family: var(--font-mono);
  font-size: 1rem;
  font-weight: 600;
  color: var(--silver-light);
  min-width: 20px;
  text-align: center;
}
.btu-row.active .btu-qty-val { color: var(--royal-2); }

/* result panel */
.btu-calc-result {
  padding: var(--space-4);
  background: linear-gradient(180deg, rgba(30,91,191,0.08), transparent 80%), var(--charcoal-2);
  display: flex;
  flex-direction: column;
}
.btu-result-eyebrow {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--silver-deep);
  margin-bottom: var(--space-1);
}
.btu-result-total {
  font-family: var(--font-display);
  font-size: clamp(2rem, 4vw, 3rem);
  font-weight: 700;
  color: var(--silver-light);
  letter-spacing: 0.02em;
  line-height: 1;
}
.btu-result-total .unit {
  font-size: 0.4em;
  color: var(--royal-2);
  margin-left: 0.5rem;
  letter-spacing: 0.1em;
}
.btu-result-detail {
  font-size: 0.875rem;
  color: var(--silver-mid);
  margin-top: 0.5rem;
}
.btu-result-divider {
  height: 1px;
  background: var(--hairline);
  margin: var(--space-3) 0;
}
.btu-result-tank {
  font-family: var(--font-display);
  font-size: 2rem;
  font-weight: 600;
  color: var(--cyan);
  letter-spacing: 0.02em;
  line-height: 1.1;
}
.btu-result-tank-desc {
  font-size: 0.875rem;
  color: var(--silver-mid);
  margin-top: 0.75rem;
  line-height: 1.5;
}
.btu-result-cta {
  margin-top: auto;
  padding-top: var(--space-3);
}
.btu-result-cta .btn { width: 100%; justify-content: center; }
.btu-result-disclaimer {
  font-size: 0.75rem;
  color: var(--silver-deep);
  margin-top: var(--space-2);
  line-height: 1.5;
  font-style: italic;
}

.btu-reset {
  background: none;
  border: none;
  color: var(--silver-deep);
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  cursor: pointer;
  padding: 0;
  transition: color 0.2s ease;
}
.btu-reset:hover { color: var(--royal-2); }

/* -- CHECKLIST -------------------------------------------- */
.checklist-progress {
  background: var(--charcoal-2);
  border: 1px solid var(--hairline);
  border-radius: 6px;
  padding: var(--space-3);
  margin-bottom: var(--space-4);
  display: flex;
  align-items: center;
  gap: var(--space-3);
  flex-wrap: wrap;
}
.checklist-progress-bar-wrap {
  flex: 1;
  min-width: 200px;
  height: 8px;
  background: var(--charcoal);
  border-radius: 4px;
  overflow: hidden;
  position: relative;
}
.checklist-progress-bar {
  height: 100%;
  background: linear-gradient(90deg, var(--royal), var(--cyan));
  border-radius: 4px;
  width: 0%;
  transition: width 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}
.checklist-progress-label {
  font-family: var(--font-mono);
  font-size: 1rem;
  font-weight: 600;
  color: var(--silver-light);
  letter-spacing: 0.05em;
  min-width: 50px;
  text-align: right;
}
.checklist-progress-count {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.1em;
  color: var(--silver-deep);
}
.checklist-progress-count strong { color: var(--cyan); font-weight: 600; }

.checklist-actions {
  display: flex;
  gap: 0.75rem;
  flex-wrap: wrap;
}
.checklist-action-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.5rem 0.9rem;
  background: var(--charcoal);
  border: 1px solid var(--hairline-strong);
  border-radius: 3px;
  color: var(--silver-light);
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  cursor: pointer;
  transition: all 0.2s ease;
}
.checklist-action-btn:hover {
  border-color: var(--royal-2);
  color: var(--royal-2);
}
.checklist-action-btn svg {
  width: 14px; height: 14px;
  stroke: currentColor;
  fill: none;
  stroke-width: 2;
}

.check-group {
  margin-bottom: var(--space-4);
}
.check-group-header {
  display: flex;
  align-items: baseline;
  gap: 1rem;
  margin-bottom: var(--space-3);
  padding-bottom: var(--space-2);
  border-bottom: 1px solid var(--hairline);
}
.check-group-num {
  font-family: var(--font-mono);
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--royal-2);
  letter-spacing: 0.05em;
}
.check-group-title {
  font-family: var(--font-display);
  font-size: 1.5rem;
  letter-spacing: 0.02em;
  color: var(--silver-light);
  margin: 0;
  text-transform: uppercase;
}

.check-group-intro {
  color: var(--silver-mid);
  margin-bottom: var(--space-3);
  font-size: 0.9375rem;
}

.check-list {
  list-style: none;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.5rem 1rem;
}
@media (max-width: 700px) { .check-list { grid-template-columns: 1fr; } }

.check-item {
  position: relative;
}
.check-item label {
  display: flex;
  align-items: flex-start;
  gap: 0.75rem;
  padding: 0.75rem 1rem;
  background: var(--charcoal-2);
  border: 1px solid var(--hairline);
  border-radius: 4px;
  cursor: pointer;
  transition: all 0.2s ease;
}
.check-item:hover label { border-color: var(--hairline-strong); }
.check-item.checked label {
  background: linear-gradient(90deg, rgba(30,91,191,0.10), rgba(30,91,191,0.02)), var(--charcoal-2);
  border-color: rgba(30,91,191,0.35);
}

.check-item input[type="checkbox"] {
  appearance: none;
  -webkit-appearance: none;
  width: 18px; height: 18px;
  border: 2px solid var(--silver-deep);
  border-radius: 3px;
  background: transparent;
  cursor: pointer;
  flex-shrink: 0;
  margin: 0;
  margin-top: 2px;
  position: relative;
  transition: all 0.15s ease;
}
.check-item input[type="checkbox"]:hover { border-color: var(--silver-light); }
.check-item input[type="checkbox"]:checked {
  background: var(--royal);
  border-color: var(--royal);
}
.check-item input[type="checkbox"]:checked::after {
  content: "";
  position: absolute;
  left: 4px; top: 0px;
  width: 6px; height: 11px;
  border: solid white;
  border-width: 0 2.5px 2.5px 0;
  transform: rotate(45deg);
}

.check-label-text {
  font-size: 0.9375rem;
  color: var(--silver-light);
  line-height: 1.5;
  flex: 1;
}
.check-item.checked .check-label-text {
  color: var(--silver-mid);
  text-decoration: line-through;
  text-decoration-color: var(--royal-2);
  text-decoration-thickness: 1px;
}

.check-callout {
  margin: var(--space-2) 0;
  padding: var(--space-2) var(--space-3);
  background: rgba(30,91,191,0.08);
  border-left: 3px solid var(--royal-2);
  border-radius: 0 4px 4px 0;
  font-size: 0.875rem;
  color: var(--silver-light);
}
.check-callout strong {
  color: var(--cyan);
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  display: block;
  margin-bottom: 0.25rem;
}

.check-warning {
  background: rgba(255, 100, 100, 0.05);
  border: 1px solid rgba(255, 100, 100, 0.25);
  border-radius: 4px;
  padding: var(--space-3);
  margin-bottom: var(--space-3);
}
.check-warning strong {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: #ff8585;
  display: block;
  margin-bottom: 0.5rem;
}
.check-warning p {
  color: var(--silver-light);
  font-size: 0.9375rem;
  line-height: 1.6;
  margin: 0;
}

/* -- ACCORDION (FAQ) ------------------------------------- */
.accordion-item {
  background: var(--charcoal-2);
  border: 1px solid var(--hairline);
  border-radius: 4px;
  margin-bottom: 0.75rem;
  overflow: hidden;
  transition: border-color 0.2s ease;
}
.accordion-item[open] { border-color: rgba(30,91,191,0.4); }

.accordion-item summary {
  cursor: pointer;
  padding: 1.125rem 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  font-weight: 600;
  font-size: 1rem;
  color: var(--silver-light);
  list-style: none;
  transition: background 0.2s ease;
}
.accordion-item summary::-webkit-details-marker { display: none; }
.accordion-item summary:hover { background: rgba(255,255,255,0.02); }

.accordion-icon {
  width: 20px; height: 20px;
  flex-shrink: 0;
  transition: transform 0.3s ease;
  color: var(--royal-2);
}
.accordion-item[open] .accordion-icon { transform: rotate(45deg); }

.accordion-content {
  padding: 0 1.5rem 1.5rem;
  color: var(--silver-mid);
  line-height: 1.7;
  font-size: 0.9375rem;
}

/* -- PRINT STYLES (checklist) ---------------------------- */
@media print {
  body { background: white; color: black; }
  /* Force any scroll-animated content fully visible — otherwise unscrolled sections print blank */
  .fade-up { opacity: 1 !important; transform: none !important; }
  .nav, .nav-spacer, footer, .checklist-actions, .btu-reset, .check-warning, .page-hero, .mobile-call-bar, .no-print { display: none !important; }
  .checklist-progress { background: white; border: 1px solid #999; }
  .check-item label {
    background: white !important;
    border: 1px solid #ccc !important;
    color: black;
  }
  .check-label-text, .check-group-title, .check-group-intro { color: black !important; }
  .check-group-num { color: black !important; }
  .check-callout { background: #f5f5f5; border-left-color: #333; color: black; }
  .check-callout strong { color: black; }
  h1, h2, h3, h4, p { color: black !important; }
  .checklist-progress-bar { background: #333 !important; }
  section { padding: 1rem 0 !important; }
}

/* ============================================================
   v6 UPDATES — phone CTA, bigger logo/badges, sticky call bar
   ============================================================ */

/* Bigger nav logo */
.nav-logo img { height: 58px; }
@media (max-width: 900px) { .nav-logo img { height: 48px; } }

/* High-visibility click-to-call button */
.btn-call {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  padding: 1rem 1.9rem;
  background: var(--royal);
  color: #fff;
  border: 2px solid var(--royal-2);
  border-radius: 4px;
  font-family: var(--font-display);
  font-size: 1.35rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  line-height: 1;
  box-shadow: 0 6px 22px rgba(30,91,191,0.45);
  transition: all 0.2s ease;
  white-space: nowrap;
}
.btn-call:hover {
  background: var(--royal-2);
  color: #fff;
  transform: translateY(-2px);
  box-shadow: 0 10px 30px rgba(30,91,191,0.6);
}
.btn-call svg { width: 22px; height: 22px; flex-shrink: 0; }
.btn-call .call-sub {
  font-family: var(--font-mono);
  font-size: 0.6rem;
  letter-spacing: 0.2em;
  opacity: 0.85;
  display: block;
  margin-bottom: 2px;
}
@media (max-width: 480px) { .btn-call { font-size: 1.15rem; padding: 0.9rem 1.3rem; } }

/* Nav phone link — visible on desktop beside menu */
.nav-call {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  padding: 0.55rem 1.1rem;
  background: var(--royal);
  color: #fff !important;
  border-radius: 3px;
  font-family: var(--font-display) !important;
  font-size: 1.05rem !important;
  font-weight: 600 !important;
  letter-spacing: 0.03em !important;
  text-transform: none !important;
  box-shadow: 0 3px 12px rgba(30,91,191,0.4);
  transition: all 0.2s ease;
}
.nav-call:hover { background: var(--royal-2); color:#fff !important; transform: translateY(-1px); }
.nav-call svg { width: 17px; height: 17px; }

/* Sticky mobile call bar — always-visible phone on small screens */
.mobile-call-bar { display: none; }
@media (max-width: 900px) {
  .mobile-call-bar {
    display: flex;
    position: fixed;
    bottom: 0; left: 0; right: 0;
    z-index: 200;
    background: var(--royal);
    color: #fff;
    align-items: center;
    justify-content: center;
    gap: 0.6rem;
    padding: 0.95rem;
    font-family: var(--font-display);
    font-size: 1.25rem;
    font-weight: 600;
    letter-spacing: 0.04em;
    box-shadow: 0 -4px 20px rgba(0,0,0,0.5);
    border-top: 2px solid var(--royal-2);
  }
  .mobile-call-bar svg { width: 20px; height: 20px; }
  body { padding-bottom: 60px; }
}

/* Bigger, clearer credibility badges */
.cred-badges {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: clamp(2rem, 6vw, 5rem);
  flex-wrap: wrap;
}
.cred-badges img {
  opacity: 1;
  transition: transform 0.2s ease;
}
.cred-badges img:hover { transform: scale(1.04); }
.cred-badges .badge-bbb       { height: 92px; }
.cred-badges .badge-fpga      { height: 110px; }
.cred-badges .badge-chamber   { height: 140px; }
.cred-badges .badge-younggas  { height: 118px; }
@media (max-width: 600px) {
  .cred-badges .badge-bbb      { height: 68px; }
  .cred-badges .badge-fpga     { height: 80px; }
  .cred-badges .badge-chamber  { height: 104px; }
  .cred-badges .badge-younggas { height: 86px; }
}