:root {
  --navy: #10283a;
  --navy-2: #1b3d55;
  --ink: #1d2730;
  --muted: #5b6874;
  --line: #e3e8ed;
  --bg: #ffffff;
  --bg-soft: #f4f7f9;
  --accent: #f5b700;
  --accent-ink: #10283a;
  --cool: #7cc4ea;
  --cool-soft: #dff0fa;
  --radius: 14px;
  --wrap: 1120px;
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  color: var(--ink);
  line-height: 1.6;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 68px; }
body { margin: 0; background: var(--bg); }
img, svg { max-width: 100%; display: block; }
a { color: inherit; }
h1, h2, h3 { line-height: 1.2; margin: 0 0 .6em; color: var(--navy); }
h1 { font-size: clamp(2rem, 4.5vw, 3.2rem); letter-spacing: -.02em; }
h2 { font-size: clamp(1.6rem, 3vw, 2.2rem); letter-spacing: -.01em; }
h3 { font-size: 1.15rem; }
p { margin: 0 0 1em; }

.wrap { max-width: var(--wrap); margin: 0 auto; padding: 0 20px; }
.section { padding: 80px 0; }
.section--soft { background: var(--bg-soft); }
.eyebrow {
  display: inline-block; font-size: .8rem; font-weight: 700; letter-spacing: .08em;
  text-transform: uppercase; color: var(--navy-2); margin-bottom: 12px;
}
.lead { font-size: 1.15rem; color: var(--muted); max-width: 46ch; }

/* Boutons */
.btn {
  display: inline-flex; align-items: center; gap: 8px; padding: 13px 22px;
  border-radius: 999px; font-weight: 700; text-decoration: none; border: 2px solid transparent;
  transition: transform .15s ease, background .15s ease;
}
.btn:hover { transform: translateY(-1px); }
.btn--primary { background: var(--accent); color: var(--accent-ink); }
.btn--primary:hover { background: #ffc61a; }
.btn--ghost { border-color: currentColor; color: var(--navy); }
.btn--light { border-color: rgba(255,255,255,.6); color: #fff; }
.btn svg { width: 18px; height: 18px; }

/* En-tête */
.header {
  position: sticky; top: 0; z-index: 10; background: rgba(255,255,255,.94);
  backdrop-filter: blur(8px); border-bottom: 1px solid var(--line);
}
.header .wrap { display: flex; align-items: center; justify-content: space-between; height: 68px; gap: 16px; }
.logo { display: flex; align-items: center; gap: 10px; text-decoration: none; font-weight: 800; font-size: 1.3rem; color: var(--navy); }
.logo img { width: 34px; height: 34px; }
.nav { display: flex; gap: 26px; }
.nav a { text-decoration: none; color: var(--muted); font-weight: 600; font-size: .95rem; }
.nav a:hover { color: var(--navy); }
.header .btn { padding: 10px 18px; }

/* Hero */
.hero { padding: 72px 0 80px; background: linear-gradient(180deg, var(--cool-soft) 0%, #fff 100%); }
.hero .wrap { display: grid; grid-template-columns: 1.05fr .95fr; gap: 48px; align-items: center; }
.hero h1 span { color: var(--navy-2); background: linear-gradient(transparent 62%, rgba(245,183,0,.45) 62%); }
.hero .actions { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 28px; }
.zone {
  display: inline-flex; align-items: center; gap: 16px; margin-top: 28px; padding: 16px 22px 16px 16px;
  background: #fff; border: 1px solid var(--line); border-left: 5px solid var(--accent); border-radius: var(--radius);
  box-shadow: 0 12px 30px -18px rgba(16,40,58,.35);
}
.zone svg { flex: none; width: 48px; height: 48px; padding: 11px; border-radius: 12px; background: var(--navy); color: var(--accent); }
.zone small { display: block; font-size: .78rem; font-weight: 700; letter-spacing: .06em; text-transform: uppercase; color: var(--navy-2); }
.zone strong { display: block; font-size: clamp(1.2rem, 2.2vw, 1.45rem); line-height: 1.25; color: var(--navy); letter-spacing: -.01em; }
.zone span { display: block; font-size: .92rem; color: var(--muted); }

/* Maison évolutive */
.house { background: #fff; border-radius: 20px; padding: 18px; box-shadow: 0 20px 50px -24px rgba(16,40,58,.35); }
.house svg { width: 100%; height: auto; }
.house .room { fill: #eef2f5; stroke: var(--navy); stroke-width: 2; transition: fill .45s ease; }
.house .unit { fill: #fff; stroke: var(--navy); stroke-width: 1.5; opacity: 0; transition: opacity .45s ease; }
.house .air { stroke: var(--cool); stroke-width: 2; fill: none; stroke-linecap: round; opacity: 0; transition: opacity .45s ease; }
.house[data-step="1"] .s1 .room,
.house[data-step="2"] :is(.s1, .s2) .room,
.house[data-step="3"] :is(.s1, .s2, .s3) .room { fill: var(--cool-soft); }
.house[data-step="1"] .s1 :is(.unit, .air),
.house[data-step="2"] :is(.s1, .s2) :is(.unit, .air),
.house[data-step="3"] :is(.s1, .s2, .s3) :is(.unit, .air) { opacity: 1; }
.house .label { font: 600 11px system-ui, sans-serif; fill: var(--muted); }
.steps-switch { display: flex; gap: 6px; margin-top: 14px; background: var(--bg-soft); padding: 5px; border-radius: 999px; }
.steps-switch button {
  flex: 1; border: 0; background: transparent; padding: 9px 6px; border-radius: 999px;
  font: 600 .85rem system-ui, sans-serif; color: var(--muted); cursor: pointer;
}
.steps-switch button[aria-pressed="true"] { background: var(--navy); color: #fff; }

/* Section clim */
.clim-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; margin-top: 40px; counter-reset: step; }
.step { background: #fff; border: 1px solid var(--line); border-radius: var(--radius); padding: 26px; position: relative; }
.step::before {
  counter-increment: step; content: counter(step);
  display: grid; place-items: center; width: 36px; height: 36px; border-radius: 50%;
  background: var(--accent); color: var(--accent-ink); font-weight: 800; margin-bottom: 14px;
}
.step p { color: var(--muted); margin: 0; }
.perks { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; margin-top: 48px; }
.perk { display: flex; gap: 14px; align-items: flex-start; }
.perk svg { flex: none; width: 40px; height: 40px; padding: 9px; border-radius: 10px; background: var(--cool-soft); color: var(--navy-2); }
.perk h3 { margin-bottom: .25em; font-size: 1.02rem; }
.perk p { color: var(--muted); margin: 0; font-size: .95rem; }

/* Services */
.services { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; margin-top: 40px; }
.card { background: #fff; border: 1px solid var(--line); border-radius: var(--radius); padding: 28px; }
.card svg { width: 44px; height: 44px; padding: 10px; border-radius: 12px; background: var(--navy); color: var(--accent); margin-bottom: 18px; }
.card p { color: var(--muted); margin: 0; }

/* Pourquoi */
.why { display: grid; grid-template-columns: .9fr 1.1fr; gap: 48px; align-items: start; }
.why ul { list-style: none; margin: 0; padding: 0; display: grid; gap: 18px; }
.why li { display: flex; gap: 14px; }
.why li svg { flex: none; width: 24px; height: 24px; color: var(--navy-2); margin-top: 2px; }
.why li p { margin: 0; color: var(--muted); }
.why li strong { color: var(--ink); display: block; }

/* Contact */
.contact { background: var(--navy); color: #fff; border-radius: 24px; padding: 56px; display: grid; grid-template-columns: 1.2fr 1fr; gap: 40px; align-items: center; }
.contact h2 { color: #fff; }
.contact p { color: rgba(255,255,255,.75); }
.contact-list { display: grid; gap: 12px; }
.contact-list > a, .contact-list > div {
  display: flex; align-items: center; gap: 14px; padding: 16px 18px; border-radius: 14px;
  background: rgba(255,255,255,.07); text-decoration: none; color: #fff;
}
.contact-list > a:hover { background: rgba(255,255,255,.12); }
.contact-list svg { flex: none; width: 22px; height: 22px; color: var(--accent); }
.contact-list small { display: block; color: rgba(255,255,255,.6); font-size: .8rem; }
.contact-list span { font-weight: 700; }

/* Pied de page */
.footer { padding: 36px 0; color: var(--muted); font-size: .9rem; }
.footer .wrap { display: flex; flex-wrap: wrap; justify-content: space-between; gap: 12px; }
.footer a { color: var(--muted); }

/* Page mentions légales */
.legal { padding-top: 56px; padding-bottom: 80px; max-width: 760px; }
.legal h2 { font-size: 1.3rem; margin-top: 2em; }
.legal dl { display: grid; grid-template-columns: max-content 1fr; gap: 6px 20px; margin: 0; }
.legal dt { font-weight: 600; }
.legal dd { margin: 0; color: var(--muted); }

@media (max-width: 900px) {
  .hero .wrap, .why, .contact { grid-template-columns: 1fr; }
  .clim-grid, .perks, .services { grid-template-columns: 1fr; }
  .nav { display: none; }
  .section { padding: 60px 0; }
  .contact { padding: 36px 24px; }
  .hero { padding-top: 28px; }
  .footer .wrap { flex-direction: column; align-items: center; text-align: center; }
  .hero-text { display: flex; flex-direction: column; align-items: flex-start; }
  .zone { order: -1; margin: 0 0 26px; }
}
@media (max-width: 480px) {
  .header .btn span { display: none; }
  .legal dl { grid-template-columns: 1fr; }
  .legal dd { margin-bottom: 8px; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  * { transition: none !important; }
}

/* Réalisations */
.gallery { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; margin-top: 40px; }
.shot { margin: 0; }
.shot .ph, .shot img {
  aspect-ratio: 4 / 3; width: 100%; border-radius: var(--radius); object-fit: cover;
}
.shot .ph {
  display: flex; flex-direction: column; align-items: center; justify-content: center; gap: 8px;
  background: var(--bg-soft); border: 2px dashed var(--line); color: var(--muted); font-size: .9rem;
}
.shot .ph svg { width: 36px; height: 36px; opacity: .6; }
.shot figcaption { margin-top: 10px; font-weight: 600; color: var(--navy); }

/* Certifications */
.certs { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 8px; }
.cert {
  display: grid; place-items: center; text-align: center; width: 112px; height: 80px; padding: 8px;
  border-radius: 12px; background: #fff; border: 2px dashed var(--line);
  color: var(--muted); font-size: .78rem; line-height: 1.3;
}

@media (max-width: 900px) {
  .gallery { grid-template-columns: repeat(2, 1fr); gap: 14px; }
}

/* Économies de chauffage */
.savings {
  display: grid; grid-template-columns: 1.15fr .85fr; gap: 40px; align-items: center;
  margin-top: 48px; padding: 40px; border-radius: 20px; background: var(--cool-soft);
}
.savings h3 { font-size: clamp(1.35rem, 2.4vw, 1.75rem); }
.savings p { color: var(--ink); }
.savings p:last-child { margin-bottom: 0; }
.flow { display: grid; justify-items: center; gap: 6px; }
.flow-item {
  display: flex; align-items: center; gap: 14px; width: 100%; padding: 14px 18px;
  background: #fff; border-radius: 14px;
}
.flow-item svg { flex: none; width: 40px; height: 40px; padding: 9px; border-radius: 10px; background: var(--bg-soft); color: var(--navy-2); }
.flow-item p { margin: 0; color: var(--muted); font-size: .92rem; line-height: 1.35; }
.flow-item strong { display: block; color: var(--navy); font-size: 1.05rem; }
.flow-item--result { background: var(--navy); }
.flow-item--result svg { background: rgba(255,255,255,.1); color: var(--accent); }
.flow-item--result p { color: rgba(255,255,255,.75); }
.flow-item--result strong { color: #fff; }
.flow-op { font-weight: 800; font-size: 1.3rem; color: var(--navy-2); line-height: 1; }

@media (max-width: 900px) {
  .savings { grid-template-columns: 1fr; padding: 28px 20px; gap: 28px; }
}