/* ==========================================================================
   KOCH TOITURE — Design System
   Palette matériaux : ardoise, zinc, tuile, cuivre patiné
   ========================================================================== */

:root{
  /* Couleurs — inspirées des matériaux de couverture */
  --ardoise-900:#171b1e;      /* ardoise profonde / nuit */
  --ardoise-800:#20262b;
  --ardoise-700:#2c343a;
  --zinc-500:#4a5a63;         /* zinc patiné */
  --zinc-300:#8fa0a8;
  --cuivre-600:#a6592e;       /* cuivre brut / tuile */
  --cuivre-500:#c06a35;
  --patine-600:#3f8f7d;       /* cuivre oxydé / patine verte-bleue — accent signature */
  --patine-500:#4faa95;
  --pierre-100:#f4efe6;       /* pierre claire / mortier */
  --pierre-50:#faf7f1;
  --papier:#fffdf9;
  --encre:#1b2023;
  --encre-doux:#4b5359;
  --ligne:#e2dbcb;

  --font-display:"Fraunces", "Iowan Old Style", Georgia, serif;
  --font-body:"Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;

  --radius:2px;
  --shadow-soft: 0 20px 50px -25px rgba(23,27,30,0.35);
  --shadow-lift: 0 30px 70px -30px rgba(23,27,30,0.5);
  --container:1180px;
}

*,*::before,*::after{box-sizing:border-box;}
html{scroll-behavior:smooth;}
[id]{scroll-margin-top:96px;}
body{
  margin:0;
  font-family:var(--font-body);
  color:var(--encre);
  background:var(--papier);
  -webkit-font-smoothing:antialiased;
  line-height:1.6;
}
img{max-width:100%;display:block;}
a{color:inherit;text-decoration:none;}
ul{margin:0;padding:0;list-style:none;}
h1,h2,h3,h4{font-family:var(--font-display);margin:0 0 .5em;font-weight:600;line-height:1.15;color:var(--ardoise-900);}
p{margin:0 0 1em;}
.container{max-width:var(--container);margin:0 auto;padding:0 24px;}

@media (prefers-reduced-motion: reduce){
  html{scroll-behavior:auto;}
  *{animation-duration:.001ms !important;animation-iteration-count:1 !important;transition-duration:.001ms !important;}
}

:focus-visible{outline:3px solid var(--patine-500);outline-offset:3px;}

/* Eyebrow / label utilitaire ------------------------------------------- */
.eyebrow{
  display:inline-flex;
  align-items:center;
  gap:.6em;
  font-family:var(--font-body);
  font-size:.72rem;
  font-weight:700;
  letter-spacing:.16em;
  text-transform:uppercase;
  color:var(--cuivre-600);
}
.eyebrow::before{
  content:"";
  width:22px;height:2px;
  background:var(--cuivre-600);
  display:inline-block;
}
.eyebrow.on-dark{color:var(--patine-500);}
.eyebrow.on-dark::before{background:var(--patine-500);}

/* Boutons ---------------------------------------------------------------- */
.btn{
  display:inline-flex;
  align-items:center;
  gap:.55em;
  padding:15px 28px;
  font-family:var(--font-body);
  font-weight:600;
  font-size:.95rem;
  border-radius:var(--radius);
  border:1px solid transparent;
  cursor:pointer;
  transition:transform .25s ease, background .25s ease, color .25s ease, border-color .25s ease;
  white-space:nowrap;
}
.btn:hover{transform:translateY(-2px);}
.btn-primary{background:var(--cuivre-600);color:#fff;}
.btn-primary:hover{background:var(--cuivre-500);}
.btn-outline{background:transparent;border-color:rgba(255,255,255,0.55);color:#fff;}
.btn-outline:hover{background:rgba(255,255,255,0.12);border-color:#fff;}
.btn-dark{background:var(--ardoise-900);color:#fff;}
.btn-dark:hover{background:var(--ardoise-700);}
.btn-ghost{background:transparent;color:var(--ardoise-900);border-color:var(--ligne);}
.btn-ghost:hover{border-color:var(--cuivre-600);color:var(--cuivre-600);}

/* ==========================================================================
   HEADER
   ========================================================================== */
.site-header{
  position:sticky;top:0;left:0;right:0;
  z-index:100;
  background:rgba(23,27,30,0.92);
  backdrop-filter:saturate(160%) blur(10px);
  border-bottom:1px solid rgba(255,255,255,0.08);
}
.nav{
  display:flex;
  align-items:center;
  justify-content:space-between;
  padding:14px 24px;
  max-width:var(--container);
  margin:0 auto;
}
.brand{display:flex;align-items:center;gap:12px;}
.brand__logo{height:40px;width:auto;flex:none;}
.brand__logo--footer{height:36px;}
.brand__text{display:flex;flex-direction:column;line-height:1.15;}
.brand__text strong{font-family:var(--font-display);color:#fff;font-size:1.05rem;letter-spacing:.01em;}
.brand__text span{font-size:.68rem;letter-spacing:.12em;text-transform:uppercase;color:var(--zinc-300);}

.nav__links{display:flex;align-items:center;gap:6px;}
.nav__links a{
  padding:10px 16px;
  font-size:.92rem;
  font-weight:500;
  color:rgba(255,255,255,0.82);
  border-radius:var(--radius);
  transition:color .2s ease, background .2s ease;
  position:relative;
}
.nav__links a:hover{color:#fff;background:rgba(255,255,255,0.06);}
.nav__links a.is-active{color:#fff;}
.nav__links a.is-active::after{
  content:"";
  position:absolute;left:16px;right:16px;bottom:6px;
  height:2px;background:var(--patine-500);
}
.nav__cta{display:flex;align-items:center;gap:14px;}
.nav__phone{
  display:flex;align-items:center;gap:8px;
  color:#fff;font-weight:600;font-size:.92rem;
}
.nav__phone svg{width:16px;height:16px;color:var(--patine-500);}

.nav__toggle{
  display:none;
  background:none;border:none;cursor:pointer;
  width:40px;height:40px;
  align-items:center;justify-content:center;
  flex-direction:column;
  gap:6px;
  padding:0;
  color:#fff;
}
.nav__toggle span, .nav__toggle::before, .nav__toggle::after{
  content:"";
  display:block;
  width:24px;height:2px;
  border-radius:2px;
  background:#fff;
  transition:transform .25s ease, opacity .25s ease;
}
.nav.is-open .nav__toggle span{opacity:0;}
.nav.is-open .nav__toggle::before{transform:translateY(8px) rotate(45deg);}
.nav.is-open .nav__toggle::after{transform:translateY(-8px) rotate(-45deg);}

/* ==========================================================================
   HERO
   ========================================================================== */
.hero{
  position:relative;
  min-height:92vh;
  display:flex;
  align-items:flex-end;
  color:#fff;
  overflow:hidden;
  background:var(--ardoise-900);
}
.hero__slides{position:absolute;inset:0;}
.hero__slide{
  position:absolute;inset:0;
  background-size:cover;background-position:center;
  opacity:0;
  transition:opacity 1.4s ease;
}
.hero__slide.is-active{opacity:1;}
.hero__scrim{
  position:absolute;inset:0;
  background:linear-gradient(180deg, rgba(23,27,30,0.35) 0%, rgba(23,27,30,0.35) 40%, rgba(20,24,27,0.94) 100%);
}
.hero__content{
  position:relative;z-index:2;
  width:100%;
  padding:0 24px 88px;
  max-width:var(--container);
  margin:0 auto;
}
.hero__eyebrow{color:var(--patine-500);}
.hero__eyebrow::before{background:var(--patine-500);}
.hero h1{
  color:#fff;
  font-size:clamp(2.4rem, 5.4vw, 4.4rem);
  max-width:16ch;
  margin:.35em 0 .4em;
}
.hero__lead{
  font-size:1.12rem;
  max-width:46ch;
  color:rgba(255,255,255,0.86);
}
.hero__ctas{display:flex;gap:14px;flex-wrap:wrap;margin-top:26px;}
.hero__dots{
  position:relative;z-index:2;
  display:flex;gap:8px;
  max-width:var(--container);margin:0 auto;
  padding:0 24px 34px;
}
.hero__dots button{
  width:34px;height:3px;border:none;background:rgba(255,255,255,0.35);cursor:pointer;padding:0;
  transition:background .25s ease;
}
.hero__dots button.is-active{background:var(--patine-500);}

.hero--page{min-height:64vh;align-items:center;}
.hero--page .hero__content{padding-bottom:0;}

/* ==========================================================================
   ROOF DIAGRAM — élément signature (coupe de toiture)
   ========================================================================== */
.roofcut{background:var(--ardoise-900);color:#fff;padding:96px 0;}
.roofcut__head{max-width:640px;margin:0 au0 56px;}
.roofcut__head h2{color:#fff;}
.roofcut__head p{color:var(--zinc-300);}
.roofcut__diagram{
  display:grid;
  gap:2px;
  border-radius:var(--radius);
  overflow:hidden;
  margin-top:48px;
}
.roofcut__layer{
  display:grid;
  grid-template-columns:64px 1fr 2fr;
  align-items:center;
  gap:24px;
  padding:22px 22px;
  background:var(--ardoise-800);
  border-left:3px solid transparent;
  transition:background .25s ease, border-color .25s ease;
}
.roofcut__layer:hover{background:var(--ardoise-700);border-left-color:var(--patine-500);}
.roofcut__num{
  font-family:var(--font-display);
  font-size:1.4rem;
  color:var(--patine-500);
}
.roofcut__name{font-weight:700;font-size:1.02rem;color:#fff;}
.roofcut__desc{color:var(--zinc-300);font-size:.94rem;margin:0;}
@media (max-width:720px){
  .roofcut__layer{grid-template-columns:36px 1fr;}
  .roofcut__desc{grid-column:2 / -1;}
}

/* ==========================================================================
   SECTIONS GÉNÉRIQUES
   ========================================================================== */
section{padding:96px 0;}
.section-tight{padding:72px 0;}
.section-head{max-width:640px;margin:0 0 48px;}
.section-head.center{margin-left:auto;margin-right:auto;text-align:center;}
.bg-stone{background:var(--pierre-100);}
.bg-dark{background:var(--ardoise-900);color:#fff;}
.bg-dark h2,.bg-dark h3{color:#fff;}
.bg-dark p{color:rgba(255,255,255,0.78);}

.split{
  display:grid;
  grid-template-columns:1fr 1fr;
  gap:64px;
  align-items:center;
}
@media (max-width:860px){.split{grid-template-columns:1fr;gap:36px;}}

.split__media{position:relative;}
.split__media img{border-radius:var(--radius);box-shadow:var(--shadow-soft);}
.split__media--stack{display:grid;gap:16px;}
.split__frame{
  position:absolute;
  border:1px solid var(--cuivre-600);
  width:70%;height:70%;
  z-index:-1;
}
.split__frame--tl{top:-20px;left:-20px;}

.lede{font-size:1.08rem;color:var(--encre-doux);}

/* Grille de compétences / matériaux -------------------------------------- */
.grid-cards{
  display:grid;
  grid-template-columns:repeat(auto-fit, minmax(230px,1fr));
  gap:1px;
  background:var(--ligne);
  border:1px solid var(--ligne);
}
.card{
  background:var(--papier);
  padding:34px 28px;
  transition:background .25s ease;
}
.card:hover{background:var(--pierre-50);}
.card__icon{
  width:44px;height:44px;
  margin-bottom:18px;
  color:var(--cuivre-600);
}
.card h3{font-size:1.08rem;margin-bottom:.4em;}
.card p{font-size:.92rem;color:var(--encre-doux);margin:0;}

/* Zones d'intervention ----------------------------------------------------*/
.zones{
  display:grid;
  grid-template-columns:1.1fr 1fr;
  gap:64px;
  align-items:start;
}
@media (max-width:860px){.zones{grid-template-columns:1fr;}}
.zones__tags{display:flex;flex-wrap:wrap;gap:10px;}
.zones__tags span{
  padding:9px 16px;
  font-size:.86rem;
  border:1px solid var(--ligne);
  border-radius:20px;
  color:var(--encre-doux);
}
.zones__map{
  border:1px solid var(--ligne);
  background:var(--pierre-50);
  padding:32px;
  border-radius:var(--radius);
}
.zones__map dl{display:grid;grid-template-columns:auto 1fr;gap:12px 16px;font-size:.95rem;}
.zones__map dt{color:var(--cuivre-600);font-weight:700;}
.zones__map dd{margin:0;color:var(--encre-doux);}

/* Garantie ----------------------------------------------------------------*/
.guarantee{
  display:grid;
  grid-template-columns:auto 1fr;
  gap:36px;
  align-items:center;
  background:var(--pierre-100);
  border:1px solid var(--ligne);
  padding:40px;
  border-radius:var(--radius);
}
.guarantee img{width:120px;height:auto;}
@media (max-width:640px){.guarantee{grid-template-columns:1fr;text-align:center;}}

/* Galerie / lightbox --------------------------------------------------- */
.gallery{
  display:grid;
  grid-template-columns:repeat(4,1fr);
  gap:14px;
}
@media (max-width:760px){.gallery{grid-template-columns:repeat(2,1fr);}}
.gallery a{
  position:relative;
  display:block;
  overflow:hidden;
  border-radius:var(--radius);
  aspect-ratio:3/4;
}
.gallery img{
  width:100%;height:100%;object-fit:cover;
  transition:transform .5s ease;
}
.gallery a:hover img{transform:scale(1.07);}
.gallery a::after{
  content:"+";
  position:absolute;inset:0;
  display:flex;align-items:center;justify-content:center;
  font-family:var(--font-display);
  font-size:2rem;color:#fff;
  background:rgba(23,27,30,0.35);
  opacity:0;
  transition:opacity .25s ease;
}
.gallery a:hover::after{opacity:1;}

.lightbox{
  position:fixed;inset:0;
  background:rgba(15,18,20,0.93);
  display:none;
  align-items:center;justify-content:center;
  z-index:1000;
  padding:40px;
}
.lightbox.is-open{display:flex;}
.lightbox img{max-width:min(90vw,900px);max-height:80vh;border-radius:var(--radius);}
.lightbox__close, .lightbox__prev, .lightbox__next{
  position:absolute;
  background:rgba(255,255,255,0.08);
  border:1px solid rgba(255,255,255,0.25);
  color:#fff;width:44px;height:44px;border-radius:50%;
  cursor:pointer;
  display:flex;align-items:center;justify-content:center;
  font-size:1.2rem;
}
.lightbox__close{top:24px;right:24px;}
.lightbox__prev{left:24px;top:50%;transform:translateY(-50%);}
.lightbox__next{right:24px;top:50%;transform:translateY(-50%);}

/* Process steps (couverture) ------------------------------------------- */
.steps{display:grid;grid-template-columns:repeat(4,1fr);gap:1px;background:var(--ligne);border:1px solid var(--ligne);}
@media (max-width:860px){.steps{grid-template-columns:1fr 1fr;}}
@media (max-width:520px){.steps{grid-template-columns:1fr;}}
.step{background:var(--papier);padding:32px 26px;}
.step__num{font-family:var(--font-display);font-size:1.6rem;color:var(--cuivre-600);display:block;margin-bottom:12px;}
.step h3{font-size:1rem;margin-bottom:.35em;}
.step p{font-size:.88rem;color:var(--encre-doux);margin:0;}

/* FAQ --------------------------------------------------------------------*/
.faq-list{border-top:1px solid var(--ligne);}
.faq-item{border-bottom:1px solid var(--ligne);}
.faq-item summary{
  list-style:none;
  cursor:pointer;
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap:20px;
  padding:26px 4px;
  font-family:var(--font-display);
  font-size:1.08rem;
  color:var(--ardoise-900);
}
.faq-item summary::-webkit-details-marker{display:none;}
.faq-item summary .plus{
  flex:none;
  width:28px;height:28px;
  border:1px solid var(--ligne);
  border-radius:50%;
  display:flex;align-items:center;justify-content:center;
  color:var(--cuivre-600);
  font-size:1rem;
  transition:transform .25s ease;
}
.faq-item[open] summary .plus{transform:rotate(45deg);}
.faq-item p{padding:0 4px 26px;max-width:66ch;color:var(--encre-doux);}

/* CTA band ----------------------------------------------------------------*/
.cta-band{
  background:linear-gradient(120deg, var(--ardoise-900), var(--zinc-500));
  color:#fff;
  border-radius:var(--radius);
  padding:64px 48px;
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap:32px;
  flex-wrap:wrap;
}
.cta-band h2{color:#fff;margin-bottom:.3em;}
.cta-band p{color:rgba(255,255,255,0.8);margin:0;max-width:44ch;}

/* Contact page ------------------------------------------------------------*/
.contact-grid{display:grid;grid-template-columns:1fr 1fr;gap:64px;}
@media (max-width:860px){.contact-grid{grid-template-columns:1fr;}}
.contact-card{
  border:1px solid var(--ligne);
  padding:28px;
  border-radius:var(--radius);
  display:flex;gap:18px;
  align-items:flex-start;
  margin-bottom:16px;
}
.contact-card__icon{
  width:42px;height:42px;flex:none;
  border-radius:50%;
  background:var(--pierre-100);
  color:var(--cuivre-600);
  display:flex;align-items:center;justify-content:center;
}
.contact-card h3{font-size:.98rem;margin-bottom:.25em;}
.contact-card p{font-size:.94rem;color:var(--encre-doux);margin:0;}
.contact-card a{color:var(--cuivre-600);font-weight:600;}

.city-cloud{display:flex;flex-wrap:wrap;gap:8px;}
.city-cloud span{
  font-size:.82rem;
  padding:7px 14px;
  border:1px solid rgba(255,255,255,0.18);
  border-radius:20px;
  color:rgba(255,255,255,0.82);
}

/* Formulaire ---------------------------------------------------------------*/
.form-card{
  background:var(--pierre-50);
  border:1px solid var(--ligne);
  border-radius:var(--radius);
  padding:40px;
}
.field{margin-bottom:20px;}
.field label{display:block;font-size:.86rem;font-weight:600;margin-bottom:8px;color:var(--ardoise-900);}
.field input, .field select, .field textarea{
  width:100%;
  padding:13px 16px;
  border:1px solid var(--ligne);
  border-radius:var(--radius);
  font-family:var(--font-body);
  font-size:.95rem;
  background:#fff;
  color:var(--encre);
}
.field input:focus, .field select:focus, .field textarea:focus{
  outline:none;border-color:var(--cuivre-600);
}
.field-row{display:grid;grid-template-columns:1fr 1fr;gap:20px;}
@media (max-width:560px){.field-row{grid-template-columns:1fr;}}
.form-note{font-size:.82rem;color:var(--encre-doux);margin-top:14px;}
.form-success{
  display:none;
  border:1px solid var(--patine-600);
  background:rgba(63,143,125,0.08);
  color:var(--ardoise-900);
  padding:18px 20px;
  border-radius:var(--radius);
  margin-bottom:20px;
  font-size:.92rem;
}
.form-success.is-visible{display:block;}
.form-error{
  display:none;
  border:1px solid var(--cuivre-600);
  background:rgba(166,89,46,0.08);
  color:var(--ardoise-900);
  padding:18px 20px;
  border-radius:var(--radius);
  margin-bottom:20px;
  font-size:.92rem;
}
.form-error.is-visible{display:block;}

/* Honeypot anti-spam : masqué visuellement, toujours accessible dans le DOM */
.hp-field{
  position:absolute;
  left:-9999px;
  top:auto;
  width:1px;height:1px;
  overflow:hidden;
}

/* Captcha maths ---------------------------------------------------------- */
.captcha{
  display:flex;
  align-items:center;
  gap:10px;
  padding:14px 16px;
  background:var(--pierre-100);
  border:1px solid var(--ligne);
  border-radius:var(--radius);
  margin-bottom:20px;
  font-size:.92rem;
}
.captcha__question{
  font-weight:700;
  font-family:var(--font-display);
  color:var(--ardoise-900);
  white-space:nowrap;
}
.captcha input{
  width:80px;
  padding:10px 12px;
  border:1px solid var(--ligne);
  border-radius:var(--radius);
  font-family:var(--font-body);
}
.captcha input:focus{outline:none;border-color:var(--cuivre-600);}

/* ==========================================================================
   FOOTER
   ========================================================================== */
.site-footer{background:var(--ardoise-900);color:rgba(255,255,255,0.75);padding:72px 0 28px;}
.footer-grid{
  display:grid;
  grid-template-columns:1.4fr 1fr 1fr 1fr;
  gap:40px;
  padding-bottom:48px;
  border-bottom:1px solid rgba(255,255,255,0.1);
}
@media (max-width:860px){.footer-grid{grid-template-columns:1fr 1fr;}}
@media (max-width:520px){.footer-grid{grid-template-columns:1fr;}}
.footer-grid h4{color:#fff;font-family:var(--font-body);font-size:.78rem;letter-spacing:.1em;text-transform:uppercase;margin-bottom:18px;}
.footer-grid ul li{margin-bottom:10px;font-size:.92rem;}
.footer-grid a:hover{color:#fff;}
.footer-brand p{font-size:.92rem;max-width:32ch;color:rgba(255,255,255,0.6);}
.footer-bottom{
  padding-top:26px;
  display:flex;justify-content:space-between;flex-wrap:wrap;gap:12px;
  font-size:.82rem;color:rgba(255,255,255,0.5);
}
.footer-bottom a{color:rgba(255,255,255,0.65);}

/* ==========================================================================
   RESPONSIVE NAV
   ========================================================================== */
@media (max-width:920px){
  .nav__links, .nav__phone-wrap{display:none;}
  .nav.is-open .nav__links{
    display:flex;
    position:absolute;
    top:100%;left:0;right:0;
    background:var(--ardoise-900);
    flex-direction:column;
    padding:10px 24px 24px;
    border-bottom:1px solid rgba(255,255,255,0.08);
  }
  .nav__toggle{display:flex;}
}

/* Reveal-on-scroll ----------------------------------------------------- */
.reveal{opacity:0;transform:translateY(18px);transition:opacity .7s ease, transform .7s ease;}
.reveal.is-visible{opacity:1;transform:none;}

/* Utility spacing */
.mt-lg{margin-top:56px;}
.stack{display:flex;flex-direction:column;gap:16px;}
.hidden-mobile{display:block;}
@media (max-width:640px){.hidden-mobile{display:none;}}