/* =========================================================
   Julien Casiro | Melody Nelson
   Design system : discipline editoriale moderne
   Palette resserree, grille, filets fins, aucune ombre.
   ========================================================= */

:root {
  /* Palette resserree : encre, papier, un seul bleu */
  --paper:      #FFFFFF;
  --surface:    #F5F4EF;   /* papier chaud, sections alternees */
  --ink:        #0B0B0C;
  --ink-soft:   #55554E;
  --line:       #E4E2DA;   /* filet fin */
  --line-strong:#111112;
  --accent:     #1B39E6;   /* bleu signal, identifiant unique */
  --accent-ink: #0F2299;

  --maxw: 1160px;
  --pad: 40px;

  --font: "Helvetica Neue", Helvetica, "Liberation Sans", Arial,
          -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
}

* { margin: 0; padding: 0; box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  font-family: var(--font);
  color: var(--ink);
  background: var(--paper);
  line-height: 1.65;
  font-size: 17px;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

/* ---------- Primitives ---------- */
.wrap {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 var(--pad);
}

.eyebrow {
  font-size: .78rem;
  font-weight: 700;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--accent);
  display: inline-block;
  margin-bottom: 22px;
}

h1, h2, h3, h4 { font-weight: 800; letter-spacing: -0.02em; line-height: 1.08; }

h2 {
  font-size: clamp(1.9rem, 3.4vw, 2.9rem);
  margin-bottom: 14px;
}

.subtitle {
  font-size: 1.08rem;
  color: var(--ink-soft);
  max-width: 640px;
  margin-bottom: 52px;
  line-height: 1.6;
}
.subtitle strong { color: var(--ink); font-weight: 700; }

section { padding: 96px 0; border-top: 1px solid var(--line); }
section.alt { background: var(--surface); }

p { color: var(--ink-soft); }

/* ---------- Header ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(255,255,255,.86);
  backdrop-filter: saturate(180%) blur(10px);
  border-bottom: 1px solid var(--line);
}
.site-header .wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 66px;
}
.brand {
  font-weight: 800;
  letter-spacing: -0.01em;
  font-size: 1.02rem;
  text-decoration: none;
  color: var(--ink);
  display: inline-flex;
  align-items: center;
  gap: 10px;
}
.brand .mark {
  width: 26px; height: 26px;
  border: 1.5px solid var(--ink);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: .68rem;
  font-weight: 800;
  letter-spacing: -0.02em;
}
.nav { display: flex; gap: 30px; }
.nav a {
  text-decoration: none;
  color: var(--ink-soft);
  font-size: .92rem;
  font-weight: 600;
  transition: color .18s ease;
}
.nav a:hover { color: var(--accent); }

/* ---------- Hero ---------- */
.hero { border-top: none; padding: 118px 0 104px; }
.hero h1 {
  font-size: clamp(2.6rem, 7vw, 5.4rem);
  letter-spacing: -0.035em;
  max-width: 14ch;
  margin-bottom: 26px;
}
.hero h1 .sep { color: var(--accent); font-weight: 800; }
.hero-lede {
  font-size: clamp(1.15rem, 2.2vw, 1.5rem);
  color: var(--ink-soft);
  max-width: 640px;
  line-height: 1.5;
}
.hero-rule {
  width: 84px; height: 3px;
  background: var(--accent);
  margin-top: 48px;
}

/* ---------- Prose ---------- */
.prose p { font-size: 1.12rem; line-height: 1.75; max-width: 720px; margin-bottom: 22px; }
.prose p:last-child { margin-bottom: 0; }
.prose p strong { color: var(--ink); font-weight: 700; }

/* ---------- Solutions ---------- */
.grid-2 { display: grid; grid-template-columns: repeat(2, 1fr); gap: 0; }
.grid-2 > * {
  border-top: 1px solid var(--line);
  border-left: 1px solid var(--line);
  padding: 40px 40px 44px;
}
.grid-2 > *:nth-child(-n+2) { border-top: 1px solid var(--line-strong); }
.grid-2 { border-right: 1px solid var(--line); border-bottom: 1px solid var(--line); }

.solution h3 {
  font-size: 1.35rem;
  margin-bottom: 14px;
}
.solution .idx {
  font-size: .8rem;
  font-weight: 700;
  color: var(--accent);
  letter-spacing: .1em;
  display: block;
  margin-bottom: 18px;
}
.solution p { font-size: 1rem; line-height: 1.68; }
.solution p strong { color: var(--ink); font-weight: 700; }

/* ---------- Case studies ---------- */
.cases { display: grid; grid-template-columns: repeat(3, 1fr); gap: 28px; }
.case { border-top: 3px solid var(--ink); padding-top: 26px; }
.case h4 { font-size: 1.05rem; margin-bottom: 10px; }
.case .stat {
  font-size: clamp(3rem, 6vw, 4.4rem);
  font-weight: 800;
  color: var(--accent);
  letter-spacing: -0.04em;
  line-height: 1;
  margin: 24px 0 18px;
  font-variant-numeric: tabular-nums;
}
.case p { font-size: .95rem; line-height: 1.55; }

/* ---------- Methodology (section encre) ---------- */
.dark { background: var(--ink); color: var(--paper); border-top-color: var(--ink); }
.dark h2 { color: var(--paper); }
.dark .subtitle { color: #A7A79E; }
.phases { display: grid; grid-template-columns: repeat(4, 1fr); gap: 0; }
.phase {
  padding: 34px 26px 38px;
  border-left: 1px solid rgba(255,255,255,.14);
}
.phase:first-child { border-left: none; padding-left: 0; }
.phase .num {
  font-size: 2.4rem;
  font-weight: 800;
  color: var(--paper);
  letter-spacing: -0.04em;
  display: block;
  margin-bottom: 18px;
}
.phase .num em {
  font-style: normal;
  color: var(--accent);
}
.phase h4 { font-size: 1.05rem; color: var(--paper); margin-bottom: 10px; }
.phase p { color: #A7A79E; font-size: .92rem; line-height: 1.6; }
.phase p strong { color: #E6E6E0; font-weight: 700; }

/* ---------- Differentiators ---------- */
.diffs { display: grid; grid-template-columns: repeat(2, 1fr); gap: 40px 56px; }
.diff { display: grid; grid-template-columns: 40px 1fr; gap: 20px; align-items: start; }
.diff .ic {
  font-size: 1.5rem;
  line-height: 40px;
  text-align: center;
  filter: grayscale(.1);
}
.diff h4 { font-size: 1.12rem; margin-bottom: 8px; }
.diff p { font-size: .98rem; line-height: 1.62; }
.diff p strong { color: var(--ink); font-weight: 700; }

/* ---------- Ecosystem ---------- */
.eco { display: grid; grid-template-columns: repeat(5, 1fr); gap: 0;
  border-top: 1px solid var(--line-strong);
  border-left: 1px solid var(--line);
}
.eco-link {
  padding: 26px 22px 30px;
  border-right: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  text-decoration: none;
  display: block;
  transition: background .18s ease, color .18s ease;
}
.eco-link h4 { font-size: 1rem; color: var(--ink); margin-bottom: 10px; }
.eco-link p { font-size: .86rem; line-height: 1.5; color: var(--ink-soft); }
.eco-link .go {
  display: inline-block;
  margin-top: 16px;
  font-size: .82rem;
  font-weight: 700;
  color: var(--accent);
  letter-spacing: .02em;
}
.eco-link:hover { background: var(--ink); }
.eco-link:hover h4,
.eco-link:hover p { color: var(--paper); }
.eco-link:hover .go { color: #8fa0ff; }

/* ---------- Footer ---------- */
.site-footer {
  background: var(--ink);
  color: var(--paper);
  padding: 72px 0 64px;
}
.site-footer .wrap { display: grid; gap: 10px; }
.site-footer .f-brand { font-size: 1.3rem; font-weight: 800; letter-spacing: -0.02em; }
.site-footer p { color: #A7A79E; font-size: .96rem; }
.site-footer a { color: var(--paper); text-decoration: none; border-bottom: 1px solid rgba(255,255,255,.35); }
.site-footer a:hover { color: #8fa0ff; border-color: #8fa0ff; }
.site-footer .f-legal { margin-top: 26px; font-size: .82rem; color: #6f6f68; }

/* ---------- Reveal ---------- */
.reveal { opacity: 0; transform: translateY(22px); transition: opacity .6s ease, transform .6s ease; }
.reveal.is-visible { opacity: 1; transform: translateY(0); }
@media (prefers-reduced-motion: reduce) {
  .reveal { opacity: 1; transform: none; transition: none; }
  html { scroll-behavior: auto; }
}

/* ---------- Responsive ---------- */
@media (max-width: 900px) {
  :root { --pad: 24px; }
  .nav { display: none; }
  section { padding: 68px 0; }
  .hero { padding: 84px 0 72px; }
  .cases { grid-template-columns: 1fr; gap: 0; }
  .case { border-top: 1px solid var(--line); padding: 28px 0; }
  .case:first-child { border-top: 3px solid var(--ink); }
  .phases { grid-template-columns: 1fr 1fr; }
  .phase { border-left: 1px solid rgba(255,255,255,.14); padding: 26px 20px; }
  .phase:first-child { padding-left: 20px; }
  .diffs { grid-template-columns: 1fr; gap: 32px; }
  .eco { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 560px) {
  .grid-2 { grid-template-columns: 1fr; }
  .grid-2 > * { border-left: 1px solid var(--line); }
  .grid-2 > *:nth-child(2) { border-top: 1px solid var(--line); }
  .phases { grid-template-columns: 1fr; }
  .phase { border-left: none; border-top: 1px solid rgba(255,255,255,.14); padding: 24px 0; }
  .phase:first-child { border-top: none; }
  .eco { grid-template-columns: 1fr; }
}