:root {
  --bg:        #f6f7f4;
  --bg-alt:    #eceee8;
  --paper:     #ffffff;
  --ink:       #10161c;
  --ink-body:  #2f3a44;
  --muted:     #66727d;
  --teal:      #0b6e6e;
  --teal-dark: #085555;
  --amber:     #d97b2b;
  --amber-dark:#b8621c;
  --line:      rgba(16, 22, 28, 0.14);
  --line-soft: rgba(16, 22, 28, 0.08);
  --shadow:    0 20px 60px rgba(16, 22, 28, 0.10);
  --shadow-sm: 0 8px 24px rgba(16, 22, 28, 0.07);
  --radius:    10px;
  --font-display: "Space Grotesk", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --font-body: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --maxw: 1080px;
}

* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  font-family: var(--font-body);
  font-size: 17px;
  line-height: 1.6;
  color: var(--ink-body);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
}
a { color: var(--teal); text-decoration: none; }
a:hover { color: var(--teal-dark); }
h1, h2, h3 { font-family: var(--font-display); color: var(--ink); line-height: 1.12; letter-spacing: -0.01em; }
h1 { font-size: clamp(38px, 5vw, 58px); font-weight: 700; }
h2 { font-size: clamp(28px, 3.4vw, 38px); font-weight: 600; margin-bottom: 22px; }
h3 { font-size: 19px; font-weight: 600; margin-bottom: 8px; }
p { max-width: 68ch; }
strong { color: var(--ink); }

.container { max-width: var(--maxw); margin: 0 auto; padding: 0 24px; }
.container.narrow { max-width: 800px; }

/* Buttons */
.btn {
  display: inline-block;
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 16px;
  padding: 14px 24px;
  border-radius: 999px;
  border: 1px solid transparent;
  transition: background 0.15s, color 0.15s, transform 0.1s;
  white-space: nowrap;
}
.btn:active { transform: translateY(1px); }
.btn-primary { background: var(--amber); color: #fff; }
.btn-primary:hover { background: var(--amber-dark); color: #fff; }
.btn-ghost { background: transparent; color: var(--ink); border-color: var(--line); }
.btn-ghost:hover { border-color: var(--ink); color: var(--ink); }
.btn-sm { padding: 10px 18px; font-size: 15px; }

/* Nav */
.nav {
  position: sticky; top: 0; z-index: 20;
  background: rgba(246, 247, 244, 0.92);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--line-soft);
}
.nav-row { display: flex; align-items: center; gap: 28px; height: 66px; }
.wordmark { display: flex; align-items: center; gap: 12px; color: var(--ink); }
.wordmark-svg { height: 26px; width: auto; display: block; }
.wordmark-full { font-family: var(--font-display); font-weight: 600; font-size: 15px; color: var(--ink); }
.nav-links { display: flex; gap: 22px; margin-left: auto; font-size: 15px; }
.nav-links a { color: var(--ink-body); }
.nav-links a:hover { color: var(--ink); }

/* Hero */
.hero { padding: 72px 0 64px; border-bottom: 1px solid var(--line-soft); }
.hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.1fr) minmax(320px, 0.9fr);
  gap: clamp(36px, 5vw, 72px);
  align-items: center;
}
.eyebrow {
  font-size: 13px; letter-spacing: 0.12em; text-transform: uppercase;
  color: var(--teal); font-weight: 600; margin-bottom: 18px;
}
.hero h1 { margin-bottom: 22px; max-width: 620px; }
.lede { font-size: 19px; margin-bottom: 28px; max-width: 560px; }
.cta-row { display: flex; gap: 12px; flex-wrap: wrap; }
.trust { font-size: 14px; color: var(--muted); margin-top: 16px; max-width: 520px; }

/* Chat card */
.chat-card {
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 14px;
  box-shadow: var(--shadow);
  overflow: hidden;
  font-size: 15px;
}
.chat-head {
  display: flex; align-items: center; gap: 10px;
  padding: 12px 16px;
  background: var(--ink); color: #fff;
  font-family: var(--font-display); font-weight: 600;
}
.chat-head .dot { width: 9px; height: 9px; border-radius: 50%; background: #3ddc97; }
.chat-tag { margin-left: auto; font-size: 11px; font-weight: 500; letter-spacing: 0.08em; text-transform: uppercase; color: #b8c2cb; }
.chat-body { padding: 16px; display: flex; flex-direction: column; gap: 10px; }
.msg { max-width: 88%; padding: 10px 14px; border-radius: 14px; line-height: 1.45; }
.msg.them { align-self: flex-end; background: var(--bg-alt); color: var(--ink); border-bottom-right-radius: 4px; }
.msg.us { align-self: flex-start; background: #e6f2f2; color: var(--ink); border-bottom-left-radius: 4px; }
.msg.cta { background: var(--teal); color: #fff; font-weight: 600; }
.msg.cta strong { color: #fff; }
.chat-foot { padding: 12px 16px; border-top: 1px solid var(--line-soft); font-size: 13px; color: var(--muted); }

/* Proof bar */
.proofbar { background: var(--ink); color: #dfe6ec; padding: 40px 0; }
.stats { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; }
.stat .num { font-family: var(--font-display); font-size: 40px; font-weight: 700; color: #fff; line-height: 1; }
.stat .lab { font-size: 13px; letter-spacing: 0.04em; color: #b8c2cb; margin-top: 8px; max-width: 200px; }
.proof-note { font-size: 14px; color: #b8c2cb; margin-top: 28px; max-width: 80ch; }

/* Sections */
.section { padding: 72px 0; }
.section.alt { background: var(--bg-alt); }
.section-lede { font-size: 18px; margin-bottom: 32px; }
.aside { color: var(--muted); margin-top: 20px; }

.leak { list-style: none; display: flex; flex-direction: column; gap: 16px; }
.leak li { padding-left: 22px; position: relative; max-width: 68ch; }
.leak li::before {
  content: ""; position: absolute; left: 0; top: 11px;
  width: 9px; height: 9px; border-radius: 50%; background: var(--amber);
}

.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; }
.card {
  background: var(--paper);
  border: 1px solid var(--line-soft);
  border-radius: var(--radius);
  padding: 22px 22px 24px;
  box-shadow: var(--shadow-sm);
}
.card p { font-size: 15.5px; }

.steps { list-style: none; counter-reset: step; display: flex; flex-direction: column; gap: 26px; }
.steps li { position: relative; padding-left: 58px; counter-increment: step; }
.steps li::before {
  content: counter(step);
  position: absolute; left: 0; top: 0;
  width: 40px; height: 40px; border-radius: 50%;
  background: var(--teal); color: #fff;
  font-family: var(--font-display); font-weight: 700; font-size: 18px;
  display: flex; align-items: center; justify-content: center;
}
.guarantee {
  margin-top: 36px;
  padding: 18px 22px;
  border-left: 4px solid var(--amber);
  background: var(--paper);
  border-radius: 0 var(--radius) var(--radius) 0;
}

/* Pricing */
.tiers { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; align-items: stretch; }
.tier {
  background: var(--paper);
  border: 1px solid var(--line-soft);
  border-radius: var(--radius);
  padding: 26px 24px;
  box-shadow: var(--shadow-sm);
}
.tier.featured { border-color: var(--teal); box-shadow: 0 0 0 3px rgba(11, 110, 110, 0.12), var(--shadow-sm); }
.tier-name { font-family: var(--font-display); font-weight: 600; color: var(--teal); letter-spacing: 0.02em; margin-bottom: 10px; }
.tier-price { font-family: var(--font-display); font-size: 15px; color: var(--muted); }
.tier-price span { font-size: 32px; font-weight: 700; color: var(--ink); margin-right: 6px; }
.tier-monthly { font-family: var(--font-display); font-size: 20px; font-weight: 600; color: var(--ink); margin: 6px 0 16px; }
.tier ul { list-style: none; display: flex; flex-direction: column; gap: 8px; font-size: 15px; }
.tier li { padding-left: 18px; position: relative; }
.tier li::before { content: "✓"; position: absolute; left: 0; color: var(--teal); font-weight: 700; }
.pricing-notes { margin-top: 28px; display: grid; grid-template-columns: 1fr 1fr; gap: 14px 28px; font-size: 15px; }
.pricing-notes p { max-width: none; }
.cta-center { text-align: center; margin-top: 36px; }

/* FAQ */
.faq dt { font-family: var(--font-display); font-weight: 600; color: var(--ink); font-size: 18px; margin-top: 22px; }
.faq dd { margin-top: 6px; max-width: 68ch; }

/* Founder */
.founder p + p { margin-top: 14px; }
.founder .links { display: flex; gap: 22px; flex-wrap: wrap; margin-top: 20px; font-weight: 600; }

.final { text-align: center; }
.final p { margin-left: auto; margin-right: auto; }

/* Footer */
.footer { border-top: 1px solid var(--line-soft); padding: 26px 0; font-size: 14px; color: var(--muted); }
.footer-row { display: flex; justify-content: space-between; gap: 16px; flex-wrap: wrap; }

/* Responsive */
@media (max-width: 900px) {
  .hero-grid { grid-template-columns: 1fr; }
  .stats { grid-template-columns: repeat(2, 1fr); }
  .grid-3 { grid-template-columns: 1fr 1fr; }
  .tiers { grid-template-columns: 1fr; }
  .pricing-notes { grid-template-columns: 1fr; }
  .nav-links { display: none; }
  .wordmark-full { display: none; }
}
@media (max-width: 560px) {
  body { font-size: 16px; }
  .hero { padding: 44px 0 48px; }
  .section { padding: 52px 0; }
  .grid-3 { grid-template-columns: 1fr; }
  .stats { grid-template-columns: 1fr 1fr; gap: 18px; }
  .stat .num { font-size: 32px; }
  .lede { font-size: 17px; }
  .msg { max-width: 94%; }
}

/* Systems card (hero) */
.sys-card {
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 14px;
  box-shadow: var(--shadow);
  overflow: hidden;
  font-size: 15px;
}
.sys-head {
  display: flex; align-items: center; gap: 10px;
  padding: 12px 16px;
  background: var(--ink); color: #fff;
  font-family: var(--font-display); font-weight: 600;
}
.sys-head .dot { width: 9px; height: 9px; border-radius: 50%; background: #3ddc97; }
.sys-list { list-style: none; padding: 6px 16px; }
.sys-list li {
  display: grid; grid-template-columns: 118px 1fr; gap: 4px 14px; align-items: start;
  padding: 12px 0; border-bottom: 1px solid var(--line-soft);
}
.sys-list li:last-child { border-bottom: 0; }
.sys-name { font-family: var(--font-display); font-weight: 600; color: var(--ink); }
.sys-desc { color: var(--ink-body); line-height: 1.45; }
.sys-tag {
  grid-column: 2; justify-self: start;
  font-size: 11px; letter-spacing: 0.08em; text-transform: uppercase; font-weight: 600;
  color: var(--teal); background: #e6f2f2; padding: 2px 8px; border-radius: 999px;
}
.sys-foot { padding: 12px 16px; border-top: 1px solid var(--line-soft); font-size: 13px; color: var(--muted); }

.grid-2 { display: grid; grid-template-columns: 1fr 1fr; gap: 18px; }
.card-tag { margin-top: 10px; font-size: 13px; font-weight: 600; color: var(--teal); }
h3.sub { margin: 36px 0 12px; font-size: 22px; }
.section-lede { max-width: 76ch; }

@media (max-width: 900px) { .grid-2 { grid-template-columns: 1fr; } }
@media (max-width: 560px) { .sys-list li { grid-template-columns: 1fr; } .sys-tag { grid-column: 1; } }

/* ---- HVAC Answer Desk sub-brand lockup ---- */
.brandmark {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 19px;
  color: var(--ink);
  letter-spacing: -0.01em;
  white-space: nowrap;
}
.wordmark-full {
  font-weight: 500;
  font-size: 13px;
  color: var(--muted);
  border-left: 1px solid var(--line);
  padding-left: 12px;
}