:root {
  --navy: #071b29;
  --navy-2: #0d2a3d;
  --orange: #ed6c27;
  --cream: #f5f2eb;
  --ink: #10212b;
  --muted: #60717c;
  --line: #dce2e4;
  --white: #fff;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; overflow-x: hidden; color: var(--ink); background: #fff; font-family: Manrope, Arial, sans-serif; line-height: 1.65; }
a { color: inherit; }
.site-header { position: sticky; top: 0; z-index: 20; display: flex; align-items: center; gap: 36px; min-height: 82px; padding: 12px clamp(22px, 5vw, 78px); color: #fff; background: rgba(7,27,41,.97); box-shadow: 0 6px 25px rgba(0,0,0,.12); }
.brand { display: flex; align-items: center; gap: 12px; min-width: max-content; text-decoration: none; }
.brand-mark { display: grid; place-items: center; width: 52px; height: 52px; overflow: hidden; border: 2px solid #fff; background: #000; box-shadow: 0 0 0 3px rgba(237,108,39,.9); }
.brand-mark img { display: block; width: 100%; height: 100%; object-fit: cover; }
.brand strong, .brand small { display: block; }
.brand strong { font-size: 15px; letter-spacing: .02em; }
.brand small { color: #aebbc3; font-size: 10px; text-transform: uppercase; letter-spacing: .13em; }
nav { display: flex; gap: 24px; margin-left: auto; }
nav a { color: #dce5ea; font-size: 13px; font-weight: 700; text-decoration: none; }
nav a:hover { color: #fff; }
.header-phone { padding: 11px 15px; border: 1px solid #426072; color: #fff; font-size: 14px; font-weight: 800; text-decoration: none; }
.menu-toggle { display: none; margin-left: auto; border: 1px solid #627683; padding: 8px 12px; color: #fff; background: transparent; }
.hero { position: relative; min-height: 690px; display: grid; align-items: center; overflow: hidden; color: #fff; background: var(--navy) url("assets/hero-gas-boiler.png") center/cover no-repeat; }
.hero-shade { position: absolute; inset: 0; background: linear-gradient(90deg, rgba(4,19,30,.98) 0%, rgba(5,22,34,.86) 46%, rgba(5,22,34,.15) 78%); }
.hero-content { position: relative; width: min(720px, 90%); margin-left: clamp(25px, 8vw, 140px); padding: 92px 0; }
.eyebrow { margin: 0 0 14px; color: var(--orange); font-size: 12px; font-weight: 800; letter-spacing: .18em; text-transform: uppercase; }
h1, h2, h3, p { margin-top: 0; }
h1 { max-width: 700px; margin-bottom: 24px; font-size: clamp(46px, 6.2vw, 86px); line-height: 1.03; letter-spacing: -.055em; }
h2 { margin-bottom: 18px; font-size: clamp(34px, 4vw, 55px); line-height: 1.1; letter-spacing: -.045em; }
h3 { line-height: 1.25; }
.hero-lead { max-width: 650px; color: #c9d4da; font-size: 18px; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 13px; margin-top: 34px; }
.button { display: inline-flex; align-items: center; justify-content: center; min-height: 52px; padding: 0 24px; border: 0; font: inherit; font-size: 14px; font-weight: 800; text-decoration: none; cursor: pointer; }
.button-primary { color: #fff; background: var(--orange); }
.button-primary:hover { background: #d95b19; }
.button-ghost { border: 1px solid #77909f; color: #fff; }
.button-dark { color: #fff; background: var(--navy); }
.hero-points { display: flex; flex-wrap: wrap; gap: 24px; margin-top: 48px; color: #d6e0e5; font-size: 12px; font-weight: 700; }
.hero-points span::before { content: "✓"; margin-right: 8px; color: var(--orange); }
.quick-contact { display: grid; grid-template-columns: 1.4fr auto; align-items: center; gap: 45px; padding: 24px clamp(25px, 8vw, 140px); color: #fff; background: var(--orange); }
.quick-contact small, .quick-contact strong { display: block; }
.quick-contact small { opacity: .8; font-size: 11px; text-transform: uppercase; letter-spacing: .13em; }
.quick-contact a { overflow-wrap: anywhere; font-weight: 800; text-decoration: none; }
.section { padding: 105px clamp(25px, 8vw, 140px); }
.section-heading { max-width: 760px; margin-bottom: 50px; }
.section-heading > p:last-child { max-width: 650px; color: var(--muted); }
.service-grid { display: grid; grid-template-columns: repeat(3, 1fr); border: 1px solid var(--line); }
.service-card { position: relative; min-height: 330px; padding: 40px 30px; border-right: 1px solid var(--line); border-bottom: 1px solid var(--line); background: #fff; }
.service-card:nth-child(3n) { border-right: 0; }
.service-card:nth-last-child(-n+3) { border-bottom: 0; }
.service-card.featured { color: #fff; background: var(--navy-2); }
.service-number { display: block; margin-bottom: 55px; color: var(--orange); font-size: 13px; font-weight: 800; }
.service-card h3 { font-size: 22px; }
.service-card p { color: var(--muted); font-size: 14px; }
.service-card.featured p { color: #bdcad1; }
.service-card a { position: absolute; bottom: 34px; color: var(--orange); font-size: 13px; font-weight: 800; }
.process { padding: 105px clamp(25px, 8vw, 140px); color: #fff; background: var(--navy); }
.light .eyebrow { color: #ff8a4c; }
.process-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1px; background: #2b4352; }
.process-grid article { padding: 38px; background: var(--navy); }
.process-grid b { color: var(--orange); font-size: 38px; }
.process-grid p { color: #adbdc6; }
.work-gallery { background: #fff; }
.gallery-heading { margin: 0 0 20px; font-size: 25px; }
.service-heading { margin-top: 55px; }
.gallery-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; }
.gallery-grid figure { margin: 0; overflow: hidden; background: var(--navy); }
.gallery-grid img { display: block; width: 100%; aspect-ratio: 4 / 3; object-fit: cover; transition: transform .35s ease; }
.gallery-grid figure:hover img { transform: scale(1.025); }
.gallery-grid .before-after { grid-column: span 2; }
.comparison-images { display: grid; grid-template-columns: 1fr 1fr; gap: 2px; background: var(--orange); }
.comparison-images div { position: relative; overflow: hidden; }
.comparison-images div > span { position: absolute; z-index: 2; top: 14px; left: 14px; padding: 7px 10px; color: #fff; background: rgba(7,27,41,.9); font-size: 10px; font-weight: 800; letter-spacing: .08em; text-transform: uppercase; }
.gallery-grid figcaption { display: grid; gap: 5px; padding: 22px; color: #fff; }
.gallery-grid figcaption span { color: #adbdc6; font-size: 13px; }
.service-photo-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px; }
.service-photo-grid figure { margin: 0; overflow: hidden; border-bottom: 3px solid var(--orange); background: var(--navy); }
.service-photo-grid img { display: block; width: 100%; aspect-ratio: 4 / 3; object-fit: cover; }
.service-photo-grid figcaption { padding: 17px; color: #fff; font-size: 13px; }
.illustration-note { margin: 15px 0 0; color: var(--muted); font-size: 11px; }
.credentials { background: var(--cream); }
.credential-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 14px; }
.credential-grid article { padding: 25px; border-left: 4px solid var(--orange); background: #fff; box-shadow: 0 8px 30px rgba(16,33,43,.06); }
.credential-gallery article { padding: 0; overflow: hidden; }
.credential-gallery a { display: block; height: 100%; color: inherit; text-decoration: none; }
.credential-gallery img { display: block; width: 100%; aspect-ratio: 4 / 5; object-fit: cover; border-bottom: 1px solid var(--line); }
.credential-gallery strong, .credential-gallery span { padding-left: 20px; padding-right: 20px; }
.credential-gallery strong { padding-top: 18px; }
.credential-gallery span { padding-bottom: 22px; }
.credential-grid strong, .credential-grid span { display: block; }
.credential-grid span { margin-top: 5px; color: var(--muted); font-size: 13px; }
.credential-note { max-width: 800px; margin: 28px 0 0; color: var(--muted); font-size: 13px; }
.manuals { display: flex; align-items: center; justify-content: space-between; gap: 40px; padding: 70px clamp(25px, 8vw, 140px); background: #e7ecee; }
.manuals div { max-width: 720px; }
.manuals h2 { font-size: clamp(32px, 4vw, 48px); }
.contact { display: grid; grid-template-columns: .9fr 1.1fr; gap: clamp(50px, 8vw, 120px); }
.contact-copy dl { margin-top: 40px; }
.contact-copy dl div { padding: 16px 0; border-bottom: 1px solid var(--line); }
dt { color: var(--muted); font-size: 11px; font-weight: 800; letter-spacing: .13em; text-transform: uppercase; }
dd { margin: 4px 0 0; font-weight: 700; }
dd a { text-decoration: none; }
.contact-form { display: grid; grid-template-columns: 1fr 1fr; gap: 18px; padding: 35px; background: var(--cream); }
.contact-form label { color: #465761; font-size: 12px; font-weight: 700; }
.contact-form label:nth-of-type(5), .contact-form label:nth-of-type(6), .contact-form small { grid-column: 1 / -1; }
input, textarea { width: 100%; margin-top: 7px; border: 1px solid #ccd5d9; padding: 13px; color: var(--ink); background: #fff; font: inherit; }
textarea { resize: vertical; }
.contact-form small { color: var(--muted); }
footer { display: flex; align-items: center; justify-content: space-between; gap: 25px; padding: 30px clamp(25px, 8vw, 140px); color: #aebbc3; background: #05141e; font-size: 12px; }
footer p { margin: 0; }
footer > a { color: #fff; }
.thanks-page { min-height: 100vh; display: grid; place-items: center; padding: 25px; color: #fff; background: var(--navy); }
.thanks-card { width: min(620px, 100%); padding: clamp(35px, 7vw, 70px); background: var(--navy-2); box-shadow: 0 25px 80px rgba(0,0,0,.25); }
.thanks-card .brand-mark { margin-bottom: 35px; }
.thanks-card h1 { margin-bottom: 15px; font-size: clamp(48px, 9vw, 80px); }
.thanks-card p:not(.eyebrow) { margin-bottom: 30px; color: #c9d4da; }

@media (max-width: 1050px) {
  nav, .header-phone { display: none; }
  .menu-toggle { display: block; }
  nav.open { position: absolute; top: 82px; left: 0; right: 0; display: grid; gap: 0; padding: 12px 24px 24px; background: var(--navy); }
  nav.open a { padding: 13px 0; border-bottom: 1px solid #29404e; }
  .service-grid { grid-template-columns: 1fr 1fr; }
  .service-card:nth-child(3n) { border-right: 1px solid var(--line); }
  .service-card:nth-child(2n) { border-right: 0; }
  .service-card:nth-last-child(-n+3) { border-bottom: 1px solid var(--line); }
  .quick-contact { grid-template-columns: 1fr; gap: 10px; }
}

@media (max-width: 720px) {
  .site-header { min-height: 70px; gap: 10px; padding: 10px 18px; }
  .brand-mark { width: 46px; height: 46px; }
  .brand { min-width: 0; }
  .brand strong { font-size: 13px; }
  .brand small { font-size: 9px; }
  .menu-toggle { flex: 0 0 auto; }
  .hero { min-height: 650px; background-position: 62% center; }
  .hero-shade { background: rgba(4,19,30,.8); }
  .hero-content { width: auto; margin: 0; padding: 80px 24px; }
  .hero-lead { max-width: calc(100vw - 48px); }
  .hero-points { max-width: calc(100vw - 48px); gap: 12px; }
  h1 { font-size: 48px; }
  .section { padding: 75px 22px; }
  .service-grid, .process-grid, .credential-grid, .gallery-grid, .service-photo-grid, .contact { grid-template-columns: 1fr; }
  .gallery-grid .before-after { grid-column: auto; }
  .comparison-images { grid-template-columns: 1fr; }
  .service-card, .service-card:nth-child(2), .service-card:nth-child(3n) { border-right: 0; border-bottom: 1px solid var(--line); }
  .service-card:last-child { border-bottom: 0; }
  .manuals { align-items: flex-start; flex-direction: column; padding: 60px 22px; }
  .contact-form { grid-template-columns: 1fr; padding: 24px; }
  .contact-form label { grid-column: 1 / -1; }
  footer { align-items: flex-start; flex-direction: column; padding: 35px 22px; }
}