:root {
  --fond: #fbfaf7;
  --fond-alt: #f1efe8;
  --texte: #1c1f1e;
  --texte-doux: #55605c;
  --accent: #1f6f5c;
  --accent-fonce: #17574a;
  --bord: #e2ded3;
  --rayon: 14px;
  --max: 1080px;
  color-scheme: light dark;
}
@media (prefers-color-scheme: dark) {
  :root {
    --fond: #121514;
    --fond-alt: #1a1f1d;
    --texte: #eef1ef;
    --texte-doux: #a7b2ad;
    --accent: #4fbf9f;
    --accent-fonce: #6fd3b5;
    --bord: #2a312e;
  }
}
*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  font-size: 17px;
  line-height: 1.6;
  color: var(--texte);
  background: var(--fond);
}
.conteneur { width: 100%; max-width: var(--max); margin: 0 auto; padding: 0 20px; }
a { color: var(--accent); }
h1, h2, h3 { line-height: 1.2; letter-spacing: -0.01em; }
h1 { font-size: clamp(2rem, 5vw, 3.2rem); margin: 0.3em 0; max-width: 18ch; }
h2 { font-size: clamp(1.5rem, 3.2vw, 2.1rem); margin: 0 0 1em; }
h3 { font-size: 1.1rem; margin: 0 0 0.4em; }

.entete { position: sticky; top: 0; background: color-mix(in srgb, var(--fond) 90%, transparent); backdrop-filter: blur(8px); border-bottom: 1px solid var(--bord); z-index: 10; }
.entete__ligne { display: flex; align-items: center; justify-content: space-between; min-height: 64px; gap: 16px; }
.logo { font-weight: 700; text-decoration: none; color: var(--texte); }
nav { display: flex; align-items: center; gap: 18px; }
nav a { text-decoration: none; color: var(--texte-doux); font-size: 0.95rem; }
nav a:hover { color: var(--texte); }

.bouton { display: inline-block; background: var(--accent); color: #fff; text-decoration: none; padding: 0.8em 1.4em; border-radius: 999px; font-weight: 600; transition: background 0.15s; }
.bouton:hover { background: var(--accent-fonce); }
nav a.bouton { color: #fff; }
.bouton--petit { padding: 0.45em 1em; font-size: 0.9rem; }
.lien { font-weight: 600; text-decoration: none; }

.hero { padding: clamp(56px, 10vw, 120px) 0 clamp(48px, 8vw, 96px); }
.surtitre { color: var(--accent); font-weight: 600; font-size: 0.9rem; text-transform: uppercase; letter-spacing: 0.06em; margin: 0; }
.chapo { font-size: 1.15rem; color: var(--texte-doux); max-width: 56ch; }
.actions { display: flex; flex-wrap: wrap; align-items: center; gap: 20px; margin-top: 28px; }

.section { padding: clamp(48px, 8vw, 88px) 0; }
.section--alt { background: var(--fond-alt); }
.grille { display: grid; grid-template-columns: repeat(auto-fit, minmax(230px, 1fr)); gap: 18px; }
.carte { background: var(--fond); border: 1px solid var(--bord); border-radius: var(--rayon); padding: 22px; }
.carte p { margin: 0; color: var(--texte-doux); }

.etapes { margin: 0; padding-left: 1.3em; display: grid; gap: 14px; max-width: 64ch; }
.etapes li::marker { color: var(--accent); font-weight: 700; }

.contact { text-align: center; }
.contact p { color: var(--texte-doux); }
.centre { margin-inline: auto; }

.pied { border-top: 1px solid var(--bord); padding: 28px 0; color: var(--texte-doux); font-size: 0.9rem; }

@media (max-width: 560px) {
  nav a:not(.bouton) { display: none; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
}