/* ==========================================================================
   Boiler Technologies Unlimited Inc. — btuinc.net
   Shared stylesheet
   Audience: building engineers, supers, facility managers. Mobile-first.
   Tone: technical, credible, no-nonsense.
   ========================================================================== */

:root {
  --ink:        #14181d;
  --ink-2:      #39424c;
  --ink-3:      #5c6773;
  --rule:       #d8dde3;
  --rule-soft:  #eceff2;
  --paper:      #ffffff;
  --paper-2:    #f6f8fa;
  --steel:      #1f3a5f;   /* primary — precision, not heat */
  --steel-dk:   #16293f;
  --ember:      #c2410c;   /* accent, used sparingly */
  --ok:         #15803d;
  --warn-bg:    #fff8e6;
  --warn-rule:  #e0b64a;

  --wrap: 46rem;
  --wrap-wide: 68rem;

  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
          "Helvetica Neue", Arial, sans-serif;
}

*, *::before, *::after { box-sizing: border-box; }

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

body {
  margin: 0;
  font-family: var(--font);
  font-size: 17px;
  line-height: 1.65;
  color: var(--ink);
  background: var(--paper);
  -webkit-font-smoothing: antialiased;
}

/* --------------------------------------------------------------- header -- */

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: var(--paper);
  border-bottom: 1px solid var(--rule);
}

.site-header__bar {
  max-width: var(--wrap-wide);
  margin: 0 auto;
  padding: 0.7rem 1.1rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

/* Logo is a swappable <img>. Do not bake the mark into CSS or SVG sprites —
   see brief §12.2: the logo must be replaceable without a rebuild. */
/* Brand lockup.
   The legal name carries real weight here on purpose. Two reasons:
   1. It is the differentiator's anchor — the shop's reputation is the pitch.
   2. TCR reviewers check that the name on the site matches the registered
      brand exactly. A name that reads as a caption is easy to overlook.
   "BTU" is the mark; "Boiler Technologies Unlimited Inc." is the entity, and
   both stay visible at every width down to 320px. */
.site-logo {
  display: flex;
  align-items: center;
  gap: 0.65rem;
  text-decoration: none;
  min-width: 0;
}
.site-logo img { display: block; height: 44px; width: auto; }
.site-logo__fallback {
  font-weight: 800;
  font-size: clamp(1.5rem, 5.5vw, 2rem);
  line-height: 1;
  letter-spacing: 0.01em;
  color: var(--steel);
  border-bottom: 3px solid var(--ember);
  padding-bottom: 2px;
  flex: none;
}
.site-logo__sub {
  display: block;
  font-size: 0.63rem;
  font-weight: 700;
  line-height: 1.25;
  text-transform: uppercase;
  letter-spacing: 0.085em;
  color: var(--ink-2);
  border-left: 1px solid var(--rule);
  padding-left: 0.65rem;
}
@media (min-width: 40rem) {
  .site-logo__sub { font-size: 0.72rem; letter-spacing: 0.1em; }
}
/* Very narrow phones: the entity name would crowd the call button, so drop
   the divider and shrink rather than hiding the name outright. */
@media (max-width: 22rem) {
  .site-logo { gap: 0.45rem; }
  .site-logo__sub { font-size: 0.55rem; letter-spacing: 0.05em; border-left: 0; padding-left: 0.35rem; }
}

/* ---------------------------------------------------------------------------
   DARK HEADER VARIANT — required by the chrome/flame marks.
   Both supplied logos have their background baked into the artwork (pure black
   on one, a glow gradient on the other), so on the default white header they
   render as a hard rectangle. Adding .site-header--dark to <header> lets the
   mark's own ground disappear into the bar.
   This is a consequence of the artwork, not a style preference — a mark with a
   transparent background would not need it.
   --------------------------------------------------------------------------- */
.site-header--dark { background: #0d1117; border-bottom-color: #232c37; }
.site-header--dark .site-logo__fallback { color: #e8eef5; border-bottom-color: var(--ember); }
.site-header--dark .site-logo__sub { color: #93a1b1; border-left-color: #2b3540; }
.site-header--dark .call-btn { background: var(--ember); }
.site-header--dark .call-btn:hover, .site-header--dark .call-btn:focus { background: #9a330a; }
.site-header--dark .site-nav { background: #131a22; border-top-color: #232c37; }
.site-header--dark .site-nav a { color: #9fb0c2; }
.site-header--dark .site-nav a:hover { color: #fff; }
.site-header--dark .site-nav a[aria-current="page"] { color: #fff; border-bottom-color: var(--ember); }
/* The mark replaces the "BTU" text but never the entity name beside it —
   at header size the wordmark inside the artwork is not reliably legible. */
.site-header--dark .site-logo img { height: 44px; width: auto; display: block; }

/* Persistent click-to-call — required by brief §12 */
.call-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  background: var(--steel);
  color: #fff;
  text-decoration: none;
  font-weight: 700;
  font-size: 1rem;
  padding: 0.6rem 0.95rem;
  border-radius: 4px;
  white-space: nowrap;
}
.call-btn:hover, .call-btn:focus { background: var(--steel-dk); }
.call-btn svg { width: 1em; height: 1em; fill: currentColor; flex: none; }
/* Show the actual number in the header on essentially every phone, not just
   tablets. "We answer the phone" is the differentiator — an icon-only button
   hides the one piece of information the whole site is pointing at.
   22rem = 352px, below the narrowest phone in real use. */
.call-btn__label { display: none; }
@media (min-width: 22rem) { .call-btn__label { display: inline; } }

.site-nav { border-top: 1px solid var(--rule-soft); background: var(--paper-2); }
.site-nav ul {
  max-width: var(--wrap-wide);
  margin: 0 auto;
  padding: 0 0.6rem;
  list-style: none;
  display: flex;
  gap: 0.2rem;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  scrollbar-width: none;
}
.site-nav ul::-webkit-scrollbar { display: none; }
.site-nav a {
  display: block;
  padding: 0.6rem 0.7rem;
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--ink-2);
  text-decoration: none;
  white-space: nowrap;
  border-bottom: 3px solid transparent;
}
.site-nav a:hover { color: var(--steel); }
.site-nav a[aria-current="page"] { color: var(--steel); border-bottom-color: var(--steel); }

/* ----------------------------------------------------------------- page -- */

main { display: block; }

.wrap { max-width: var(--wrap); margin: 0 auto; padding: 2.2rem 1.1rem 3.5rem; }
.wrap--wide { max-width: var(--wrap-wide); }
/* A page head sitting directly above a .band would stack its own bottom
   padding on top of the band's top padding. Let the band own that space. */
.wrap--head { padding-bottom: 0.4rem; }
.wrap--head .page-head { margin-bottom: 0; }

.page-head { border-bottom: 2px solid var(--ink); padding-bottom: 1rem; margin-bottom: 2rem; }
.page-head h1 { margin: 0 0 0.35rem; font-size: 1.95rem; line-height: 1.2; letter-spacing: -0.01em; }
.page-head .meta { margin: 0; font-size: 0.85rem; color: var(--ink-3); }

h2 {
  font-size: 1.2rem;
  line-height: 1.3;
  margin: 2.4rem 0 0.7rem;
  padding-top: 0.9rem;
  border-top: 1px solid var(--rule-soft);
}
h2:first-of-type { border-top: 0; padding-top: 0; margin-top: 1.6rem; }
h3 { font-size: 1rem; margin: 1.6rem 0 0.5rem; }

p { margin: 0 0 1rem; }
ul, ol { margin: 0 0 1rem; padding-left: 1.3rem; }
li { margin-bottom: 0.4rem; }
a { color: var(--steel); }
strong { font-weight: 700; }
hr { border: 0; border-top: 1px solid var(--rule); margin: 2.5rem 0; }

address { font-style: normal; }

/* Verbatim regulatory text. Anything inside .verbatim is quoted language that
   must match the TCR submission character for character. Do not reword,
   reformat, or "improve" it. */
.verbatim {
  background: var(--paper-2);
  border-left: 4px solid var(--steel);
  padding: 1.1rem 1.2rem;
  margin: 1.2rem 0 1.4rem;
  font-size: 0.96rem;
}
.verbatim p:last-child { margin-bottom: 0; }

.callout {
  background: var(--warn-bg);
  border: 1px solid var(--warn-rule);
  border-radius: 4px;
  padding: 1rem 1.15rem;
  margin: 1.4rem 0;
  font-size: 0.95rem;
}
.callout p:last-child { margin-bottom: 0; }

/* -------------------------------------------------------------- contact -- */

.phone-first {
  background: var(--steel);
  color: #fff;
  border-radius: 6px;
  padding: 1.6rem 1.3rem;
  margin-bottom: 2.2rem;
  text-align: center;
}
.phone-first h2 {
  border: 0; padding: 0;
  margin: 0 0 0.5rem;
  font-size: 1.05rem;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: #a9c4e4;
}
.phone-first .tel {
  display: inline-block;
  font-size: clamp(1.9rem, 8vw, 2.6rem);
  font-weight: 800;
  letter-spacing: -0.02em;
  color: #fff;
  text-decoration: none;
  line-height: 1.1;
}
.phone-first .tel:hover { text-decoration: underline; }
.phone-first .answer { margin: 0.6rem 0 0; font-size: 1.05rem; font-weight: 600; }
.phone-first .fine { margin: 0.75rem 0 0; font-size: 0.9rem; color: #c3d5e8; }

.cols { display: grid; gap: 2rem; }
@media (min-width: 48rem) { .cols { grid-template-columns: 1fr 1fr; gap: 2.6rem; } }

/* ===================================================================== home
   No photography anywhere in this design (brief §12: real photos or none,
   and none exist yet). The page has to carry on type, rule, and color.
   Every block below is built so that dropping a real photo in later is an
   addition, not a rescue.
   ==================================================================== */

.hero {
  background: var(--steel-dk);
  color: #fff;
  padding: 3rem 1.1rem 3.2rem;
  border-bottom: 5px solid var(--ember);
}
.hero__inner { max-width: var(--wrap-wide); margin: 0 auto; }
.hero__eyebrow {
  margin: 0 0 1.15rem;
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: #7fa5d0;
}
/* Entity name sits above the descriptor, at size, in white — the name is the
   asset here, not a caption on one. */
.hero__name {
  display: block;
  margin-bottom: 0.45rem;
  font-size: clamp(0.95rem, 2.8vw, 1.18rem);
  letter-spacing: 0.055em;
  color: #fff;
}
/* The challenge. Brief §6 item 1: this is the hero message, in Frankie's
   words, and it must not be sanded down into marketing language. */
.hero h1 {
  margin: 0 0 1.2rem;
  font-size: clamp(1.85rem, 6.2vw, 3.1rem);
  line-height: 1.12;
  letter-spacing: -0.025em;
  font-weight: 800;
  max-width: 18ch;
}
.hero__quote {
  max-width: 60ch;
  margin: 0 0 1.9rem;
  font-size: clamp(1rem, 2.4vw, 1.13rem);
  line-height: 1.6;
  color: #d3e0ee;
}
.hero__quote strong { color: #fff; }
.hero__actions { display: flex; flex-wrap: wrap; gap: 0.8rem; align-items: center; }
.hero .call-btn {
  background: var(--ember);
  font-size: 1.12rem;
  padding: 0.85rem 1.4rem;
}
.hero .call-btn:hover, .hero .call-btn:focus { background: #9a330a; }
.hero .call-btn__label { display: inline; }
.btn-ghost {
  display: inline-flex;
  align-items: center;
  padding: 0.85rem 1.3rem;
  border: 1px solid #52709a;
  border-radius: 4px;
  color: #d3e0ee;
  font-weight: 600;
  text-decoration: none;
}
.btn-ghost:hover { border-color: #fff; color: #fff; }
.hero__area {
  margin: 1.9rem 0 0;
  padding-top: 1.3rem;
  border-top: 1px solid #33507a;
  font-size: 0.92rem;
  color: #a9c4e4;
}

.band { padding: 3rem 1.1rem; }
.band--tint { background: var(--paper-2); border-top: 1px solid var(--rule); border-bottom: 1px solid var(--rule); }
.band--ink { background: var(--ink); color: #fff; }
/* The insurance line and a closing CTA can land back to back (Services).
   Two --ink bands in a row read as one undifferentiated black slab, so the
   trust band gets the steel tone and --ink stays reserved for closers. */
.band--steel { background: var(--steel-dk); color: #fff; }
.band--steel .band__lede, .band--steel .trust p { color: #b9c3cd; }
.band--steel .pillar { border-top-color: var(--ember); }
.band__inner { max-width: var(--wrap-wide); margin: 0 auto; }
.band h2 {
  border: 0;
  padding: 0;
  margin: 0 0 0.6rem;
  font-size: clamp(1.35rem, 3.6vw, 1.75rem);
  letter-spacing: -0.015em;
}
.band__lede { max-width: 62ch; margin: 0 0 2rem; color: var(--ink-2); font-size: 1.03rem; }
.band--ink .band__lede { color: #b9c3cd; }

.grid-3 { display: grid; gap: 1.4rem; }
@media (min-width: 34rem) { .grid-3 { grid-template-columns: repeat(2, 1fr); } }
@media (min-width: 56rem) { .grid-3 { grid-template-columns: repeat(3, 1fr); } }

.pillar { border-top: 3px solid var(--steel); padding-top: 1rem; }
.pillar h3 { margin: 0 0 0.45rem; font-size: 1.05rem; }
.pillar p { margin: 0; font-size: 0.96rem; color: var(--ink-2); }
.band--ink .pillar { border-top-color: var(--ember); }
.band--ink .pillar p { color: #b9c3cd; }

.svc {
  display: block;
  border: 1px solid var(--rule);
  border-radius: 6px;
  padding: 1.2rem 1.25rem;
  text-decoration: none;
  color: inherit;
  background: var(--paper);
  transition: border-color .12s, transform .12s;
}
.svc:hover { border-color: var(--steel); transform: translateY(-2px); }
.svc h3 { margin: 0 0 0.4rem; font-size: 1.03rem; color: var(--steel); }
.svc p { margin: 0; font-size: 0.93rem; color: var(--ink-2); line-height: 1.55; }

/* Depth callout — Viessmann. Brief §4: "should get its own named callout,
   not be buried in a generic list." */
.depth {
  display: grid;
  gap: 1.5rem;
  border: 1px solid var(--rule);
  border-left: 5px solid var(--ember);
  border-radius: 6px;
  background: var(--paper);
  padding: 1.6rem 1.5rem;
}
@media (min-width: 50rem) { .depth { grid-template-columns: 1.15fr 1fr; gap: 2.4rem; } }
.depth h3 { margin: 0 0 0.6rem; font-size: 1.2rem; }
.depth p { margin: 0 0 0.9rem; color: var(--ink-2); }
.depth p:last-child { margin-bottom: 0; }
.depth ul { margin: 0; padding-left: 1.2rem; font-size: 0.95rem; color: var(--ink-2); }

/* Brands as TEXT, never logos. Brief §5 + §10: manufacturer logo usage rules
   differ per brand and "getting this wrong is the kind of thing that
   generates a letter." Do not swap these for image files. */
.brand-strip {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  list-style: none;
  margin: 0 0 1.4rem;
  padding: 0;
}
.brand-strip li {
  margin: 0;
  border: 1px solid var(--rule);
  border-radius: 3px;
  background: var(--paper);
  padding: 0.4rem 0.7rem;
  font-size: 0.87rem;
  font-weight: 600;
  color: var(--ink-2);
  letter-spacing: 0.01em;
}
.brand-strip li[data-authorized] {
  border-color: var(--steel);
  color: var(--steel);
  background: #f2f6fb;
}
.brand-key { font-size: 0.85rem; color: var(--ink-3); margin: 0 0 1.4rem; }
.brand-key b { color: var(--steel); }

/* The insurance line. Brief §4: "the single most persuasive sentence on the
   site." Given room to breathe on purpose. */
.trust {
  max-width: var(--wrap);
  margin: 0 auto;
  text-align: center;
}
.trust blockquote {
  margin: 0 0 1rem;
  font-size: clamp(1.15rem, 3.2vw, 1.5rem);
  line-height: 1.45;
  font-weight: 600;
  letter-spacing: -0.01em;
}
.trust p { margin: 0; color: #b9c3cd; font-size: 0.98rem; }

.stat-row { display: grid; gap: 1.6rem; }
@media (min-width: 40rem) { .stat-row { grid-template-columns: repeat(3, 1fr); } }
.stat { border-left: 3px solid var(--ember); padding-left: 1rem; }
.stat b {
  display: block;
  font-size: clamp(1.9rem, 5vw, 2.4rem);
  line-height: 1;
  letter-spacing: -0.03em;
  color: var(--ink);
}
.stat span { display: block; margin-top: 0.35rem; font-size: 0.93rem; color: var(--ink-2); }

.serve-list {
  columns: 2;
  column-gap: 2rem;
  list-style: none;
  margin: 0;
  padding: 0;
  font-size: 0.96rem;
}
@media (min-width: 52rem) { .serve-list { columns: 3; } }
.serve-list li {
  break-inside: avoid;
  margin-bottom: 0.5rem;
  padding-left: 1rem;
  position: relative;
  color: var(--ink-2);
}
.serve-list li::before {
  content: "";
  position: absolute;
  left: 0; top: 0.62em;
  width: 5px; height: 5px;
  background: var(--ember);
}

.closer { text-align: center; }
.closer h2 { margin-bottom: 0.7rem; }
.closer p { max-width: 52ch; margin: 0 auto 1.6rem; color: #b9c3cd; }
.closer .call-btn { background: var(--ember); font-size: 1.15rem; padding: 0.9rem 1.6rem; }
.closer .call-btn:hover { background: #9a330a; }
.closer .call-btn__label { display: inline; }

.card { border: 1px solid var(--rule); border-radius: 6px; padding: 1.3rem; }
.card h3 { margin-top: 0; }

/* ----------------------------------------------------------------- form -- */

.form-note {
  border-left: 4px solid var(--ember);
  background: #fff5ef;
  padding: 0.9rem 1.1rem;
  margin-bottom: 1.5rem;
  font-size: 0.95rem;
}
.form-note p:last-child { margin-bottom: 0; }

.field { margin-bottom: 1.1rem; }
.field label { display: block; font-weight: 600; font-size: 0.92rem; margin-bottom: 0.3rem; }
.field .opt { font-weight: 400; color: var(--ink-3); }

.field input[type="text"],
.field input[type="tel"],
.field input[type="email"],
.field textarea {
  width: 100%;
  font: inherit;
  font-size: 16px; /* prevents iOS zoom on focus */
  color: var(--ink);
  background: var(--paper);
  border: 1px solid #aeb6bf;
  border-radius: 4px;
  padding: 0.6rem 0.7rem;
}
.field input:focus, .field textarea:focus {
  outline: 2px solid var(--steel);
  outline-offset: 1px;
  border-color: var(--steel);
}
.field textarea { min-height: 7rem; resize: vertical; }

/* TCR consent block.
   HARD REQUIREMENTS (brief §8.3):
     - checkbox unchecked by default  -> no `checked` attribute, ever
     - consent text verbatim          -> see .verbatim rule above
     - Privacy Policy + Terms linked directly inside the consent text
   Do not restyle this into something that reads as fine print. */
.consent {
  border: 1px solid var(--rule);
  border-radius: 4px;
  background: var(--paper-2);
  padding: 1rem 1.1rem;
  margin: 1.5rem 0;
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 0.75rem;
  align-items: start;
}
.consent input[type="checkbox"] {
  width: 1.25rem;
  height: 1.25rem;
  margin: 0.15rem 0 0;
  accent-color: var(--steel);
  flex: none;
}
.consent label { font-size: 0.9rem; line-height: 1.55; color: var(--ink-2); }
.consent a { font-weight: 600; }

.btn-submit {
  font: inherit;
  font-weight: 700;
  font-size: 1.02rem;
  color: #fff;
  background: var(--steel);
  border: 0;
  border-radius: 4px;
  padding: 0.8rem 1.6rem;
  cursor: pointer;
  width: 100%;
}
@media (min-width: 30rem) { .btn-submit { width: auto; } }
.btn-submit:hover { background: var(--steel-dk); }
.btn-submit:disabled { background: #9aa4ae; cursor: not-allowed; }

.form-status { margin-top: 1rem; font-size: 0.95rem; font-weight: 600; }
.form-status[data-state="error"] { color: var(--ember); }
.form-status[data-state="ok"] { color: var(--ok); }
.field-error { display: block; margin-top: 0.3rem; font-size: 0.85rem; font-weight: 600; color: var(--ember); }

/* --------------------------------------------------------------- footer -- */

.site-footer {
  border-top: 1px solid var(--rule);
  background: var(--paper-2);
  padding: 2.2rem 1.1rem 2.6rem;
  font-size: 0.9rem;
  color: var(--ink-2);
}
.site-footer__inner {
  max-width: var(--wrap-wide);
  margin: 0 auto;
  display: grid;
  gap: 1.6rem;
}
@media (min-width: 44rem) {
  .site-footer__inner { grid-template-columns: 1.3fr 1fr 1fr; }
}
.site-footer h4 {
  margin: 0 0 0.5rem;
  font-size: 0.78rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--ink-3);
}
.site-footer ul { list-style: none; margin: 0; padding: 0; }
.site-footer li { margin-bottom: 0.35rem; }
.site-footer a { color: var(--ink-2); text-decoration: none; }
.site-footer a:hover { color: var(--steel); text-decoration: underline; }
/* Footer carries the full legal entity name at size — the last thing a TCR
   reviewer scrolls past, and it must read as the registered name, not fine
   print. */
.site-footer .legal-name {
  display: block;
  font-weight: 800;
  font-size: 1.05rem;
  line-height: 1.25;
  letter-spacing: -0.005em;
  color: var(--ink);
  margin-bottom: 0.4rem;
  padding-bottom: 0.4rem;
  border-bottom: 2px solid var(--ember);
}
@media (min-width: 44rem) { .site-footer .legal-name { max-width: 15rem; } }
.site-footer .copyright {
  max-width: var(--wrap-wide);
  margin: 1.8rem auto 0;
  padding-top: 1.2rem;
  border-top: 1px solid var(--rule);
  font-size: 0.82rem;
  color: var(--ink-3);
}

.skip-link {
  position: absolute; left: -9999px;
  background: var(--ink); color: #fff; padding: 0.6rem 1rem; z-index: 100;
}
.skip-link:focus { left: 0.5rem; top: 0.5rem; }

@media print {
  .site-header, .site-nav, .site-footer { display: none; }
  body { font-size: 11pt; }
}