/* ==========================================================================
   VS Fenêtre — Design system
   Signature: technical window-profile cross-sections + DPE-style energy bar
   ========================================================================== */

:root{
  /* --- Color tokens --- */
  --anthracite:      #23272B; /* RAL 7016-inspired frame grey — primary */
  --anthracite-2:     #343A40; /* lighter surface / hover */
  --paper:            #FAF8F4; /* warm base background */
  --mist:             #E8EEEC; /* cool glass tint, section alt bg */
  --oak:               #AD7F52; /* wood accent */
  --amber:             #DE9138; /* CTA / signal accent */
  --eco:                #5E8F68; /* energy-efficient green */
  --alert:               #B4503B; /* low-efficiency red, form errors */
  --ink:                  #1B1D1F;
  --ink-soft:              #565C61;
  --line:                   #D8D3C8;
  --white:                   #FFFFFF;

  /* --- Type tokens --- */
  --font-display: "Big Shoulders Display", "Arial Narrow", sans-serif;
  --font-body: "Public Sans", "Segoe UI", Arial, sans-serif;
  --font-mono: "IBM Plex Mono", "Courier New", monospace;

  --radius: 2px;
  --shadow: 0 8px 24px rgba(27,29,31,0.10);
}

@media (prefers-reduced-motion: no-preference){
  html{ scroll-behavior: smooth; }
}

*,*::before,*::after{ box-sizing: border-box; }
html,body{ margin:0; padding:0; }
body{
  font-family: var(--font-body);
  color: var(--ink);
  background: var(--paper);
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
}
img{ max-width:100%; display:block; }
svg{ max-width:100%; height:auto; display:block; }
a{ color: inherit; }
h1,h2,h3,h4{
  font-family: var(--font-display);
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.01em;
  line-height: 1.05;
  margin: 0 0 0.4em;
  color: var(--anthracite);
}
h1{ font-size: clamp(2.4rem, 5vw, 4.4rem); }
h2{ font-size: clamp(1.8rem, 3.4vw, 2.7rem); }
h3{ font-size: 1.35rem; }
p{ margin: 0 0 1em; color: var(--ink-soft); max-width: 62ch; }
.eyebrow{
  font-family: var(--font-mono);
  font-size: 0.78rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--oak);
  display: flex;
  align-items: center;
  gap: 0.6em;
  margin-bottom: 0.9em;
}
.eyebrow::before{
  content:"";
  width: 26px; height: 2px;
  background: var(--oak);
  display:inline-block;
}

:focus-visible{
  outline: 3px solid var(--amber);
  outline-offset: 2px;
}

.container{
  width: 100%;
  max-width: 1180px;
  margin: 0 auto;
  padding: 0 24px;
}
section{ padding: 84px 0; }
.section-alt{ background: var(--mist); }
.section-dark{ background: var(--anthracite); color: var(--paper); }
.section-dark h2, .section-dark h3{ color: var(--paper); }
.section-dark p{ color: #C7CDD1; }

/* --- Buttons --- */
.btn{
  display:inline-flex; align-items:center; gap:0.5em;
  font-family: var(--font-mono);
  font-size: 0.86rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  padding: 0.95em 1.6em;
  border-radius: var(--radius);
  border: 1px solid transparent;
  cursor: pointer;
  text-decoration: none;
  transition: transform .15s ease, background .15s ease, color .15s ease, border-color .15s ease;
}
.btn-primary{ background: var(--amber); color: var(--anthracite); font-weight:700; }
.btn-primary:hover{ background:#c97f28; transform: translateY(-2px); }
.btn-outline{ border-color: currentColor; color: var(--anthracite); background: transparent; }
.btn-outline:hover{ background: var(--anthracite); color: var(--paper); }
.section-dark .btn-outline{ color: var(--paper); }
.section-dark .btn-outline:hover{ background: var(--paper); color: var(--anthracite); }

/* --- Header / nav --- */
.site-header{
  position: sticky; top:0; z-index: 50;
  background: rgba(250,248,244,0.92);
  backdrop-filter: blur(6px);
  border-bottom: 1px solid var(--line);
}
.nav{
  display:flex; align-items:center; justify-content: space-between;
  padding: 16px 24px; max-width: 1180px; margin:0 auto;
}
.logo{
  font-family: var(--font-display);
  font-size: 1.5rem;
  text-transform: uppercase;
  letter-spacing: 0.02em;
  text-decoration:none;
  color: var(--anthracite);
  display:flex; align-items:baseline; gap:6px;
}
.logo span{ color: var(--oak); }
.nav-links{
  display:flex; gap: 18px; list-style:none; margin:0; padding:0; flex-wrap: wrap;
  font-family: var(--font-mono); font-size: 0.8rem; letter-spacing:.03em;
}
.nav-links a{
  text-decoration:none; color: var(--ink); padding: 6px 2px;
  border-bottom: 2px solid transparent;
}
.nav-links a:hover, .nav-links a[aria-current="page"]{ border-color: var(--amber); }
.nav-cta{ display:flex; align-items:center; gap:18px; }
.nav-phone{ font-family: var(--font-mono); font-size:0.86rem; white-space:nowrap; }
.nav-toggle{ display:none; background:none; border:1px solid var(--line); padding:8px 10px; cursor:pointer; }
@media (max-width: 1040px){
  .nav-links{
    position:absolute; top:100%; left:0; right:0;
    background: var(--paper); flex-direction:column; gap:0;
    border-bottom:1px solid var(--line);
    max-height:0; overflow:hidden; transition: max-height .25s ease;
  }
  .nav-links.open{ max-height: 480px; }
  .nav-links li{ border-top:1px solid var(--line); }
  .nav-links a{ display:block; padding: 14px 24px; }
  .nav-toggle{ display:block; }
  .nav-phone{ display:none; }
}

/* --- Hero --- */
.hero{ padding: 64px 0 40px; }
.hero-grid{
  display:grid; grid-template-columns: 1.1fr 0.9fr; gap: 56px; align-items:center;
}
@media (max-width: 860px){ .hero-grid{ grid-template-columns: 1fr; } }
.hero-stats{ display:flex; gap: 30px; margin-top: 28px; flex-wrap:wrap; }
.hero-stat b{
  display:block; font-family: var(--font-display); font-size: 2rem; color: var(--anthracite);
}
.hero-stat span{ font-family: var(--font-mono); font-size:0.76rem; color: var(--ink-soft); text-transform:uppercase; letter-spacing:.05em; }
.hero-actions{ display:flex; gap:14px; margin-top:32px; flex-wrap:wrap; }

/* --- Profile cross-section diagram (signature element) --- */
.profile-diagram{ background: var(--white); border:1px solid var(--line); padding: 18px; box-shadow: var(--shadow); }
.profile-diagram figcaption{
  font-family: var(--font-mono); font-size: 0.72rem; color: var(--ink-soft);
  display:flex; justify-content:space-between; margin-top: 10px; letter-spacing:.03em;
}

/* --- Feature / material cards --- */
.grid-3{ display:grid; grid-template-columns: repeat(3,1fr); gap: 28px; }
.grid-2{ display:grid; grid-template-columns: repeat(2,1fr); gap: 28px; }
@media (max-width: 860px){ .grid-3, .grid-2{ grid-template-columns: 1fr; } }
.card{
  background: var(--white); border:1px solid var(--line); padding: 30px;
  transition: transform .18s ease, box-shadow .18s ease;
}
.card:hover{ transform: translateY(-4px); box-shadow: var(--shadow); }
.card .tag{
  font-family: var(--font-mono); font-size:0.72rem; color: var(--oak);
  text-transform:uppercase; letter-spacing:.08em;
}
.card h3{ margin: 8px 0 10px; }
.card ul{ margin:14px 0 0; padding-left:18px; color: var(--ink-soft); font-size:0.94rem; }
.card-link{
  display:inline-flex; margin-top:16px; font-family: var(--font-mono); font-size:0.8rem;
  text-decoration:none; color: var(--anthracite); border-bottom:1px solid var(--anthracite);
}

/* --- DPE-style energy bar (real feature: shows Uw thermal performance) --- */
.energy-scale{ display:flex; flex-direction:column; gap:6px; max-width: 460px; }
.energy-row{ display:grid; grid-template-columns: 26px 1fr 70px; align-items:center; gap:10px; font-family: var(--font-mono); font-size:0.78rem; }
.energy-row .bar{ height: 22px; border-radius: 0 4px 4px 0; }
.energy-row.active .bar{ outline: 2px solid var(--anthracite); outline-offset:2px; }
.eA .bar{ background:#3E8E5C; width: 30%; }
.eB .bar{ background:#6BA35E; width: 42%; }
.eC .bar{ background:#A8B14A; width: 54%; }
.eD .bar{ background:#DCC13F; width: 66%; }
.eE .bar{ background:#DE9138; width: 78%; }
.eF .bar{ background:#C86A3B; width: 90%; }
.eG .bar{ background:#B4503B; width: 100%; }

/* --- Process steps --- */
.steps{ display:grid; grid-template-columns: repeat(4,1fr); gap:24px; counter-reset: step; }
@media (max-width: 860px){ .steps{ grid-template-columns: 1fr 1fr; } }
@media (max-width: 560px){ .steps{ grid-template-columns: 1fr; } }
.step{ border-top: 3px solid var(--oak); padding-top: 16px; }
.step::before{
  counter-increment: step; content: counter(step, decimal-leading-zero);
  font-family: var(--font-mono); color: var(--oak); font-size:0.85rem; display:block; margin-bottom:8px;
}

/* --- Testimonials --- */
.testimonial{ background: var(--white); border-left: 3px solid var(--amber); padding: 26px 28px; }
.testimonial p{ font-size: 1.05rem; color: var(--ink); font-style: italic; }
.testimonial footer{ font-family: var(--font-mono); font-size:0.78rem; color: var(--ink-soft); margin-top:10px; }

/* --- FAQ accordion --- */
.faq-item{ border-bottom: 1px solid var(--line); }
.faq-q{
  width:100%; text-align:left; background:none; border:none; cursor:pointer;
  padding: 20px 0; font-family: var(--font-body); font-weight:600; font-size:1.02rem;
  display:flex; justify-content:space-between; align-items:center; gap: 16px; color: var(--ink);
}
.faq-q .icon{ font-family: var(--font-mono); color: var(--oak); font-size:1.2rem; flex-shrink:0; }
.faq-a{ max-height:0; overflow:hidden; transition: max-height .25s ease; }
.faq-a p{ padding: 0 0 20px; }
.faq-item.open .faq-a{ max-height: 320px; }
.faq-item.open .icon{ transform: rotate(45deg); }

/* --- Forms --- */
.form-grid{ display:grid; grid-template-columns: 1fr 1fr; gap: 18px; }
@media (max-width:700px){ .form-grid{ grid-template-columns: 1fr; } }
.field{ display:flex; flex-direction:column; gap:6px; }
.field.full{ grid-column: 1 / -1; }
label{ font-family: var(--font-mono); font-size:0.76rem; text-transform:uppercase; letter-spacing:.05em; color: var(--ink-soft); }
input, select, textarea{
  font-family: var(--font-body); font-size:1rem; padding: 12px 14px;
  border:1px solid var(--line); border-radius: var(--radius); background: var(--white); color: var(--ink);
}
input:focus, select:focus, textarea:focus{ border-color: var(--anthracite); }
.field-error{ font-family: var(--font-mono); font-size:0.74rem; color: var(--alert); min-height: 1em; }
input:invalid[data-touched="true"], textarea:invalid[data-touched="true"]{ border-color: var(--alert); }
.form-note{ font-size:0.84rem; color: var(--ink-soft); }
.form-success{
  display:none; background: #E7F0E8; border:1px solid var(--eco); color:#2F5238;
  padding: 16px 18px; font-size:0.94rem; margin-bottom: 18px;
}
.form-success.show{ display:block; }
.form-error{
  display:none; background: #F5E5E1; border:1px solid var(--alert); color:#7A2E1E;
  padding: 16px 18px; font-size:0.94rem; margin-bottom: 18px;
}
.form-error.show{ display:block; }

/* --- Simple quote estimator (new feature) --- */
.estimator{ background: var(--white); border:1px solid var(--line); padding: 34px; box-shadow: var(--shadow); }
.estimator-result{
  margin-top: 22px; padding: 20px; background: var(--mist); border-left: 3px solid var(--anthracite);
  font-family: var(--font-mono); font-size:0.95rem;
}
.estimator-result b{ font-size:1.6rem; font-family: var(--font-display); display:block; color: var(--anthracite); }

/* --- Gallery (before/after + product swatches, drawn not photographic) --- */
.swatch-grid{ display:grid; grid-template-columns: repeat(4,1fr); gap:16px; }
@media (max-width: 700px){ .swatch-grid{ grid-template-columns: repeat(2,1fr); } }
.swatch{ text-align:center; }
.swatch .chip{ height: 64px; border:1px solid var(--line); margin-bottom:8px; }
.swatch span{ font-family: var(--font-mono); font-size:0.72rem; color: var(--ink-soft); }

/* --- Footer --- */
.site-footer{ background: var(--anthracite); color: #C7CDD1; padding: 60px 0 26px; }
.footer-grid{ display:grid; grid-template-columns: 1.4fr 1fr 1fr 1fr; gap: 32px; }
@media (max-width: 780px){ .footer-grid{ grid-template-columns: 1fr 1fr; } }
.site-footer h4{ color: var(--paper); font-size:0.85rem; margin-bottom:14px; }
.site-footer ul{ list-style:none; margin:0; padding:0; }
.site-footer li{ margin-bottom:8px; font-size:0.92rem; }
.site-footer a{ text-decoration:none; color: #C7CDD1; }
.site-footer a:hover{ color: var(--amber); }
.footer-bottom{
  margin-top: 46px; padding-top: 22px; border-top:1px solid #3B4147;
  display:flex; justify-content:space-between; flex-wrap:wrap; gap:10px;
  font-family: var(--font-mono); font-size:0.74rem; color:#8B9298;
}

/* --- Sticky mobile CTA (new feature) --- */
.sticky-cta{
  position: fixed; bottom:0; left:0; right:0; z-index: 60;
  background: var(--anthracite); color: var(--paper);
  display:none; justify-content:space-between; align-items:center;
  padding: 12px 18px; box-shadow: 0 -6px 18px rgba(0,0,0,0.18);
}
@media (max-width: 780px){ .sticky-cta{ display:flex; } body{ padding-bottom: 66px; } }
.sticky-cta a{ text-decoration:none; }

/* --- Breadcrumbs (SEO) --- */
.breadcrumbs{ font-family: var(--font-mono); font-size:0.76rem; color: var(--ink-soft); padding-top: 20px; }
.breadcrumbs a{ text-decoration:none; color: var(--ink-soft); }
.breadcrumbs a:hover{ color: var(--anthracite); }

/* --- Skip link (a11y) --- */
.skip-link{
  position:absolute; left:-999px; top:0; background: var(--amber); color:var(--anthracite);
  padding: 10px 16px; z-index: 100; font-family: var(--font-mono);
}
.skip-link:focus{ left: 16px; top: 16px; }

.badges{ display:flex; gap:22px; flex-wrap:wrap; align-items:center; }
.badges span{ font-family: var(--font-mono); font-size:0.76rem; color: var(--ink-soft); border:1px solid var(--line); padding:6px 12px; }