/* ============================================================
   Altus Conseil — design-system/sections/pillars.css
   ------------------------------------------------------------
   Section piliers — 3 (parfois 2 ou 4) engagements / valeurs.
   Squelette idéologique du sujet de la page.

   Class names — CONTRAT FIGÉ (consommé par Claude.ai) :
     .altus-section-pillars
       .altus-section-pillars-content
         .altus-section-pillars-header
           .altus-section-pillars-eyebrow
           .altus-section-pillars-title
         .altus-section-pillars-list
           .altus-section-pillars-item
             .altus-section-pillars-numeral       (I, II, III, IV)
             .altus-section-pillars-item-title
             .altus-section-pillars-item-lede     (catchphrase courte)
             .altus-section-pillars-item-body

   Variantes de fond — quatre combinaisons, comme le hero :
     A    .altus-section-pillars                              charbon plat
     B    .altus-section-pillars[data-altus-broll]            charbon + image
     C-flat .altus-section-pillars.altus-section-inverse      ivoire plat
     C    .altus-section-pillars.altus-section-inverse[data-altus-broll]
                                                              ivoire + image

   Requiert : colors_and_type.css.
   ============================================================ */

/* ─── Container ────────────────────────────────────────────── */

.altus-section-pillars {
  position: relative;
  background: var(--altus-bg);
  color: var(--altus-fg1);
  font-family: var(--altus-font);
  font-weight: var(--altus-w-light);
  isolation: isolate;
  padding-block: clamp(96px, 14vh, 180px);
  padding-inline: 9vw;
}

/* Première section de la page — respiration de 25vh sous le header fixé.
   Voir hero.css pour l'explication détaillée du sélecteur. */
.altus-section-pillars:first-child {
  padding-top: 25vh;
}

.altus-section-pillars-content {
  position: relative;
  z-index: 2;
  max-width: 1200px;
  margin-inline: auto;
  display: flex;
  flex-direction: column;
  gap: clamp(64px, 8vh, 96px);
}

/* ─── Header (eyebrow + title) ─────────────────────────────── */

.altus-section-pillars-header {
  display: flex;
  flex-direction: column;
  gap: 24px;
  max-width: 32ch;
}

.altus-section-pillars-eyebrow {
  margin: 0;
  font-size: 13px;
  font-weight: var(--altus-w-medium);
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--altus-accent);
}

.altus-section-pillars-title {
  margin: 0;
  font-size: clamp(36px, 4.4vw, 64px);
  font-weight: var(--altus-w-light);
  line-height: 1.08;
  letter-spacing: -0.02em;
  color: var(--altus-fg1);
  text-wrap: balance;
}

/* ─── Liste des piliers ────────────────────────────────────── */

.altus-section-pillars-list {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  column-gap: clamp(32px, 4vw, 64px);
  row-gap: 72px;
}
/* Tolérant à 2 ou 4 colonnes selon le nombre d'enfants. */
.altus-section-pillars-list:has(> :nth-child(4)) { grid-template-columns: repeat(4, 1fr); }
.altus-section-pillars-list:has(> :nth-child(2):last-child) { grid-template-columns: repeat(2, 1fr); }

.altus-section-pillars-item {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

/* Numéro romain — grand, Light 300, fg2.
   Seul élément à grande échelle non-textuel ; pas accent par défaut
   (la règle "1 bronze" est réservée à l'eyebrow). */
.altus-section-pillars-numeral {
  margin: 0 0 16px;
  /* Hairline horizontale 32 px sous le numéral pour rappeler
     la séparation entre identification et propos. */
  padding-bottom: 16px;
  border-bottom: 1px solid var(--altus-sep);
  width: max-content;
  min-width: 32px;
  font-size: clamp(40px, 4vw, 64px);
  font-weight: var(--altus-w-light);
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--altus-fg2);
  font-variant-numeric: lining-nums;
}

.altus-section-pillars-item-title {
  margin: 0;
  font-size: clamp(20px, 1.8vw, 26px);
  font-weight: var(--altus-w-medium);
  line-height: 1.2;
  letter-spacing: -0.005em;
  color: var(--altus-fg1);
}

.altus-section-pillars-item-lede {
  margin: 0;
  font-size: clamp(15px, 1.2vw, 17px);
  font-weight: var(--altus-w-light);
  line-height: 1.4;
  color: var(--altus-fg2);
}

.altus-section-pillars-item-body {
  margin: 12px 0 0;
  font-size: clamp(14px, 1vw, 15px);
  font-weight: var(--altus-w-light);
  line-height: 1.6;
  color: var(--altus-fg2);
  max-width: 36ch;
  text-wrap: pretty;
}

/* ────────────────────────────────────────────────────────────
   Variante inverse — fond ivoire (C-flat / C)
   ──────────────────────────────────────────────────────────── */
.altus-section-pillars.altus-section-inverse {
  background: var(--altus-bg-inverse);
  color: var(--altus-fg1-inverse);
}
.altus-section-pillars.altus-section-inverse .altus-section-pillars-eyebrow    { color: var(--altus-accent); }
.altus-section-pillars.altus-section-inverse .altus-section-pillars-title      { color: var(--altus-fg1-inverse); }
.altus-section-pillars.altus-section-inverse .altus-section-pillars-numeral    { color: var(--altus-fg2-inverse); border-bottom-color: rgba(20, 17, 13, 0.16); }
.altus-section-pillars.altus-section-inverse .altus-section-pillars-item-title { color: var(--altus-fg1-inverse); }
.altus-section-pillars.altus-section-inverse .altus-section-pillars-item-lede,
.altus-section-pillars.altus-section-inverse .altus-section-pillars-item-body  { color: var(--altus-fg2-inverse); }

/* ────────────────────────────────────────────────────────────
   Variante broll — fond image + voile B/C + noise
   ──────────────────────────────────────────────────────────── */
.altus-section-pillars[data-altus-broll] {
  background-image: var(--altus-broll);
  background-size: cover;
  background-position: center;
}
.altus-section-pillars[data-altus-broll]::before {
  content: '';
  position: absolute;
  inset: 0;
  background: rgba(20, 17, 13, 0.72);
  z-index: 0;
}
.altus-section-pillars.altus-section-inverse[data-altus-broll]::before {
  background: rgba(235, 229, 218, 0.88);
}
.altus-section-pillars[data-altus-broll]::after {
  content: '';
  position: absolute;
  inset: 0;
  background-image: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='320' height='320'><filter id='n'><feTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='2' seed='5' stitchTiles='stitch'/><feColorMatrix values='0 0 0 0 1 0 0 0 0 1 0 0 0 0 1 0 0 0 0.7 0'/></filter><rect width='100%25' height='100%25' filter='url(%23n)'/></svg>");
  opacity: 0.22;
  mix-blend-mode: overlay;
  z-index: 1;
  pointer-events: none;
}

/* ─── Animation d'entrée — fade discret au load ────────────── */
@media (prefers-reduced-motion: no-preference) {
  .altus-section-pillars-eyebrow,
  .altus-section-pillars-title,
  .altus-section-pillars-item {
    opacity: 0;
    animation: altus-pillars-fade-in 600ms var(--altus-ease) both;
  }
  .altus-section-pillars-eyebrow { animation-delay: 0ms; }
  .altus-section-pillars-title   { animation-delay: 80ms; }
  .altus-section-pillars-item:nth-child(1) { animation-delay: 160ms; }
  .altus-section-pillars-item:nth-child(2) { animation-delay: 240ms; }
  .altus-section-pillars-item:nth-child(3) { animation-delay: 320ms; }
  .altus-section-pillars-item:nth-child(4) { animation-delay: 400ms; }
}
@keyframes altus-pillars-fade-in {
  from { opacity: 0; transform: translateY(8px); }
  to   { opacity: 1; transform: translateY(0); }
}

/* ─── Responsive ───────────────────────────────────────────── */
@media (max-width: 1024px) {
  .altus-section-pillars-list,
  .altus-section-pillars-list:has(> :nth-child(4)) {
    grid-template-columns: repeat(2, 1fr);
  }
}
@media (max-width: 640px) {
  .altus-section-pillars {
    padding-block: clamp(72px, 12vh, 120px);
    padding-inline: 22px;
  }
  .altus-section-pillars:first-child { padding-top: 20vh; }
  .altus-section-pillars-content { gap: 56px; }
  .altus-section-pillars-list,
  .altus-section-pillars-list:has(> :nth-child(4)),
  .altus-section-pillars-list:has(> :nth-child(2):last-child) {
    grid-template-columns: 1fr;
    row-gap: 48px;
  }
}