/* 
  Tankless Water Heater Installation — North Huntingdon PA
  Design DNA: Flow · Precision · Modern Efficiency
  Mobile-first · Editorial · Product-inspired
*/

:root {
  /* Color language — water, metal, warmth */
  --color-bg: #0B1220;
  --color-surface: #111827;
  --color-surface-2: #1A2332;
  --color-border: rgba(148, 163, 184, 0.12);
  --color-text: #F1F5F9;
  --color-text-muted: #94A3B8;
  --color-text-soft: #CBD5E1;
  --color-accent: #38BDF8;
  --color-accent-soft: rgba(56, 189, 248, 0.12);
  --color-warm: #F59E0B;
  --color-warm-soft: rgba(245, 158, 11, 0.12);
  --color-success: #34D399;
  --color-white: #FFFFFF;
  --color-dark: #020617;

  /* Typography */
  --font-sans: "Inter", system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --font-display: "Outfit", "Inter", system-ui, sans-serif;

  /* Spacing & rhythm */
  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-5: 1.25rem;
  --space-6: 1.5rem;
  --space-8: 2rem;
  --space-10: 2.5rem;
  --space-12: 3rem;
  --space-16: 4rem;
  --space-20: 5rem;
  --space-24: 6rem;

  /* Radii — restrained */
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-xl: 24px;

  /* Layout */
  --max-width: 1120px;
  --header-h: 64px;
  --safe-bottom: env(safe-area-inset-bottom, 0px);

  /* Motion */
  --ease: cubic-bezier(0.22, 1, 0.36, 1);
  --duration: 0.35s;
}

/* Reset & base */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
@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 {
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.6;
  color: var(--color-text);
  background: var(--color-bg);
  min-height: 100dvh;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}
img { max-width: 100%; height: auto; display: block; }
a { color: inherit; text-decoration: none; }
ul, ol { list-style: none; }
button, input, textarea { font: inherit; color: inherit; border: none; background: none; }
button { cursor: pointer; }
:focus-visible { outline: 2px solid var(--color-accent); outline-offset: 3px; }

/* Typography scale */
.display {
  font-family: var(--font-display);
  font-weight: 600;
  letter-spacing: -0.03em;
  line-height: 1.1;
}
h1, .h1 { font-size: clamp(2rem, 6vw, 3.25rem); }
h2, .h2 { font-size: clamp(1.5rem, 4vw, 2.25rem); }
h3, .h3 { font-size: clamp(1.2rem, 3vw, 1.5rem); }
.lead { font-size: 1.125rem; color: var(--color-text-soft); line-height: 1.65; }
.meta { font-size: 0.8125rem; letter-spacing: 0.04em; text-transform: uppercase; color: var(--color-text-muted); font-weight: 500; }
.text-muted { color: var(--color-text-muted); }
.text-soft { color: var(--color-text-soft); }

/* Layout utilities */
.container {
  width: 100%;
  max-width: var(--max-width);
  margin-inline: auto;
  padding-inline: var(--space-4);
}
@media (min-width: 768px) {
  .container { padding-inline: var(--space-6); }
}
.section {
  padding-block: var(--space-12);
}
@media (min-width: 768px) {
  .section { padding-block: var(--space-16); }
}
.section-tight { padding-block: var(--space-10); }

/* Header */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(11, 18, 32, 0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-border);
  height: var(--header-h);
}
.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
  gap: var(--space-4);
}
.logo {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 1.05rem;
  letter-spacing: -0.02em;
  display: flex;
  flex-direction: column;
  line-height: 1.15;
}
.logo span { font-size: 0.7rem; font-weight: 500; color: var(--color-text-muted); letter-spacing: 0.02em; }
.nav-desktop { display: none; }
.nav-desktop ul {
  display: flex;
  gap: var(--space-1);
  align-items: center;
}
.nav-desktop a {
  padding: var(--space-2) var(--space-3);
  font-size: 0.9rem;
  color: var(--color-text-soft);
  border-radius: var(--radius-sm);
  transition: color var(--duration) var(--ease), background var(--duration) var(--ease);
}
.nav-desktop a:hover,
.nav-desktop a[aria-current="page"] {
  color: var(--color-white);
  background: var(--color-accent-soft);
}
.header-actions {
  display: flex;
  align-items: center;
  gap: var(--space-2);
}
.btn-call-header {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.55rem 0.9rem;
  background: var(--color-accent);
  color: var(--color-dark);
  font-weight: 600;
  font-size: 0.875rem;
  border-radius: var(--radius-md);
  min-height: 44px;
  transition: transform 0.2s var(--ease), background 0.2s var(--ease);
}
.btn-call-header:hover { background: #7DD3FC; transform: translateY(-1px); }
.btn-call-header svg { width: 16px; height: 16px; flex-shrink: 0; }
.menu-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  border-radius: var(--radius-sm);
  color: var(--color-text);
  background: var(--color-surface-2);
}
.menu-toggle svg { width: 22px; height: 22px; }
@media (min-width: 900px) {
  .nav-desktop { display: block; }
  .menu-toggle { display: none; }
  .logo { font-size: 1.1rem; }
}

/* Mobile nav */
.mobile-nav {
  position: fixed;
  inset: 0;
  z-index: 200;
  background: var(--color-bg);
  padding: var(--space-6);
  padding-top: calc(var(--header-h) + var(--space-6));
  transform: translateX(100%);
  transition: transform var(--duration) var(--ease);
  visibility: hidden;
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}
.mobile-nav.is-open {
  transform: translateX(0);
  visibility: visible;
}
.mobile-nav a {
  display: block;
  padding: var(--space-4);
  font-size: 1.15rem;
  font-weight: 500;
  border-radius: var(--radius-md);
  color: var(--color-text-soft);
  min-height: 48px;
}
.mobile-nav a[aria-current="page"],
.mobile-nav a:hover {
  background: var(--color-accent-soft);
  color: var(--color-white);
}
.mobile-nav-close {
  position: absolute;
  top: var(--space-4);
  right: var(--space-4);
  width: 44px;
  height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-sm);
  background: var(--color-surface-2);
}
.mobile-nav-cta {
  margin-top: auto;
  padding: var(--space-4);
}
.mobile-nav-cta .btn {
  width: 100%;
  justify-content: center;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.85rem 1.4rem;
  font-weight: 600;
  font-size: 0.95rem;
  border-radius: var(--radius-md);
  min-height: 48px;
  transition: transform 0.2s var(--ease), background 0.2s var(--ease), box-shadow 0.2s var(--ease);
  text-align: center;
}
.btn:active { transform: scale(0.98); }
.btn-primary {
  background: var(--color-accent);
  color: var(--color-dark);
}
.btn-primary:hover {
  background: #7DD3FC;
  box-shadow: 0 8px 24px rgba(56, 189, 248, 0.25);
}
.btn-secondary {
  background: var(--color-surface-2);
  color: var(--color-text);
  border: 1px solid var(--color-border);
}
.btn-secondary:hover {
  background: var(--color-surface);
  border-color: rgba(148, 163, 184, 0.25);
}
.btn-ghost {
  background: transparent;
  color: var(--color-accent);
  border: 1px solid transparent;
}
.btn-ghost:hover { background: var(--color-accent-soft); }
.btn-lg { padding: 1rem 1.6rem; font-size: 1rem; min-height: 52px; }
.btn-block { width: 100%; }

/* Hero */
.hero {
  position: relative;
  padding-block: var(--space-10) var(--space-12);
  overflow: hidden;
}
@media (min-width: 768px) {
  .hero { padding-block: var(--space-16) var(--space-20); }
}
.hero-grid {
  display: grid;
  gap: var(--space-8);
  align-items: center;
}
@media (min-width: 900px) {
  .hero-grid {
    grid-template-columns: 1.1fr 0.9fr;
    gap: var(--space-12);
  }
}
.hero-eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  margin-bottom: var(--space-4);
  padding: 0.35rem 0.75rem;
  background: var(--color-accent-soft);
  border-radius: 999px;
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--color-accent);
}
.hero h1 {
  margin-bottom: var(--space-5);
  max-width: 14ch;
}
.hero .lead {
  margin-bottom: var(--space-6);
  max-width: 36ch;
}
.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-3);
  margin-bottom: var(--space-8);
}
.hero-meta {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-4);
  padding-top: var(--space-4);
  border-top: 1px solid var(--color-border);
}
.hero-meta-item {
  display: flex;
  flex-direction: column;
  gap: 0.15rem;
}
.hero-meta-item strong {
  font-size: 0.95rem;
  font-weight: 600;
}
.hero-visual {
  position: relative;
  border-radius: var(--radius-xl);
  overflow: hidden;
  aspect-ratio: 4/5;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
}
@media (min-width: 900px) {
  .hero-visual { aspect-ratio: 1/1.05; }
}
.hero-visual img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.hero-visual-caption {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  padding: var(--space-4);
  background: linear-gradient(transparent, rgba(2, 6, 23, 0.85));
  font-size: 0.8rem;
  color: var(--color-text-soft);
}

/* Cards & info blocks */
.card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-6);
  transition: border-color var(--duration) var(--ease);
}
.card:hover { border-color: rgba(148, 163, 184, 0.22); }
.card-icon {
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-accent-soft);
  color: var(--color-accent);
  border-radius: var(--radius-md);
  margin-bottom: var(--space-4);
  font-size: 1.1rem;
}
.grid-2 {
  display: grid;
  gap: var(--space-5);
}
@media (min-width: 640px) {
  .grid-2 { grid-template-columns: 1fr 1fr; }
}
.grid-3 {
  display: grid;
  gap: var(--space-5);
}
@media (min-width: 768px) {
  .grid-3 { grid-template-columns: repeat(3, 1fr); }
}

/* Feature list */
.feature-list {
  display: grid;
  gap: var(--space-4);
}
.feature-item {
  display: flex;
  gap: var(--space-4);
  padding: var(--space-4);
  background: var(--color-surface);
  border-radius: var(--radius-md);
  border: 1px solid var(--color-border);
}
.feature-item-num {
  flex-shrink: 0;
  width: 32px;
  height: 32px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-accent-soft);
  color: var(--color-accent);
  font-weight: 600;
  font-size: 0.85rem;
  border-radius: 50%;
}
.feature-item h3 { font-size: 1.05rem; margin-bottom: 0.25rem; }
.feature-item p { font-size: 0.925rem; color: var(--color-text-muted); }

/* Process steps */
.process-steps {
  display: grid;
  gap: var(--space-6);
  counter-reset: step;
}
.process-step {
  position: relative;
  padding-left: var(--space-10);
  counter-increment: step;
}
.process-step::before {
  content: counter(step, decimal-leading-zero);
  position: absolute;
  left: 0;
  top: 0;
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 1.25rem;
  color: var(--color-accent);
  letter-spacing: -0.02em;
}
.process-step h3 { margin-bottom: var(--space-2); }
.process-step p { color: var(--color-text-muted); font-size: 0.95rem; }

/* FAQ accordion */
.faq-list { display: grid; gap: var(--space-3); }
.faq-item {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  overflow: hidden;
}
.faq-question {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
  padding: var(--space-5);
  text-align: left;
  font-weight: 550;
  font-size: 1rem;
  min-height: 56px;
  color: var(--color-text);
}
.faq-question svg {
  flex-shrink: 0;
  width: 20px;
  height: 20px;
  transition: transform 0.25s var(--ease);
  color: var(--color-text-muted);
}
.faq-item[open] .faq-question svg { transform: rotate(180deg); }
.faq-answer {
  padding: 0 var(--space-5) var(--space-5);
  color: var(--color-text-muted);
  font-size: 0.95rem;
  line-height: 1.65;
}
.faq-answer p + p { margin-top: var(--space-3); }

/* CTA band */
.cta-band {
  background: linear-gradient(145deg, var(--color-surface-2) 0%, var(--color-surface) 100%);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  padding: var(--space-8) var(--space-6);
  text-align: center;
}
@media (min-width: 640px) {
  .cta-band { padding: var(--space-10) var(--space-8); }
}
.cta-band h2 { margin-bottom: var(--space-3); }
.cta-band .lead { margin-bottom: var(--space-6); max-width: 40ch; margin-inline: auto; }
.cta-band-actions {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: var(--space-3);
}

/* Contact block */
.contact-grid {
  display: grid;
  gap: var(--space-6);
}
@media (min-width: 768px) {
  .contact-grid { grid-template-columns: 1fr 1fr; align-items: start; }
}
.contact-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-6);
}
.contact-card h3 { margin-bottom: var(--space-4); }
.contact-row {
  display: flex;
  gap: var(--space-3);
  padding: var(--space-3) 0;
  border-bottom: 1px solid var(--color-border);
  font-size: 0.95rem;
}
.contact-row:last-child { border-bottom: none; }
.contact-row strong { min-width: 5.5rem; color: var(--color-text-muted); font-weight: 500; }
.contact-row a { color: var(--color-accent); font-weight: 500; }
.contact-row a:hover { text-decoration: underline; }

/* Footer */
.site-footer {
  border-top: 1px solid var(--color-border);
  padding-block: var(--space-10) var(--space-8);
  margin-top: var(--space-12);
}
.footer-grid {
  display: grid;
  gap: var(--space-8);
  margin-bottom: var(--space-8);
}
@media (min-width: 640px) {
  .footer-grid { grid-template-columns: 1.4fr 1fr 1fr; }
}
.footer-brand .logo { margin-bottom: var(--space-3); }
.footer-brand p { font-size: 0.9rem; color: var(--color-text-muted); max-width: 28ch; }
.footer-col h4 {
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--color-text-muted);
  margin-bottom: var(--space-4);
  font-weight: 600;
}
.footer-col ul { display: grid; gap: var(--space-2); }
.footer-col a {
  font-size: 0.925rem;
  color: var(--color-text-soft);
  padding: 0.25rem 0;
}
.footer-col a:hover { color: var(--color-accent); }
.footer-bottom {
  padding-top: var(--space-6);
  border-top: 1px solid var(--color-border);
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-3);
  justify-content: space-between;
  font-size: 0.8rem;
  color: var(--color-text-muted);
}

/* Sticky mobile CTA */
.sticky-cta {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  z-index: 90;
  padding: var(--space-3) var(--space-4);
  padding-bottom: calc(var(--space-3) + var(--safe-bottom));
  background: rgba(11, 18, 32, 0.92);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border-top: 1px solid var(--color-border);
  display: flex;
  gap: var(--space-3);
  transform: translateY(100%);
  transition: transform 0.3s var(--ease);
}
.sticky-cta.is-visible { transform: translateY(0); }
.sticky-cta .btn { flex: 1; min-height: 48px; }
@media (min-width: 900px) {
  .sticky-cta { display: none; }
}

/* Page-specific adjustments */
.page-hero {
  padding-block: var(--space-10) var(--space-8);
  border-bottom: 1px solid var(--color-border);
}
.page-hero h1 { margin-bottom: var(--space-3); }
.page-hero .lead { max-width: 42ch; }

/* Image treatments */
.img-block {
  border-radius: var(--radius-lg);
  overflow: hidden;
  border: 1px solid var(--color-border);
  background: var(--color-surface);
}
.img-block img { width: 100%; height: auto; object-fit: cover; }
.img-caption {
  padding: var(--space-3) var(--space-4);
  font-size: 0.8rem;
  color: var(--color-text-muted);
  border-top: 1px solid var(--color-border);
}

/* Split section */
.split {
  display: grid;
  gap: var(--space-8);
  align-items: center;
}
@media (min-width: 800px) {
  .split { grid-template-columns: 1fr 1fr; gap: var(--space-12); }
  .split-reverse { direction: rtl; }
  .split-reverse > * { direction: ltr; }
}

/* Utility */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0,0,0,0);
  white-space: nowrap;
  border: 0;
}
.mt-4 { margin-top: var(--space-4); }
.mt-6 { margin-top: var(--space-6); }
.mt-8 { margin-top: var(--space-8); }
.mb-4 { margin-bottom: var(--space-4); }
.mb-6 { margin-bottom: var(--space-6); }
.mb-8 { margin-bottom: var(--space-8); }

/* Body padding for sticky CTA on mobile */
body.has-sticky { padding-bottom: 80px; }
@media (min-width: 900px) {
  body.has-sticky { padding-bottom: 0; }
}