:root {
  --brand: #8a5a2b;
  --brand-2: #b07a3e;
  --accent: #d9a441;
  --ink: #241a11;
  --muted: #5e5245;
  --surface: #f6eee3;
  --line: #eadfce;
  --dark: #21170f;
  --on-dark: #f8f1e6;
  --on-dark-muted: #cfc2ae;
  --header-bg: rgba(255, 251, 245, .88);
}

.hero { background: radial-gradient(1200px 600px at 85% -10%, rgba(217,164,65,.22), transparent 60%), var(--dark); color: var(--on-dark); }
.hero .lead { color: var(--on-dark-muted); }
.hero h1 em { font-style: normal; color: var(--accent); }

/* Visuel hero : coupe géologique + capteur + blocs */
.strata { width: 100%; max-width: 560px; margin-inline: auto; filter: drop-shadow(0 30px 60px rgba(0,0,0,.4)); }
.strata .block { opacity: .25; animation: blockOn 6s infinite; }
.strata .block:nth-of-type(2) { animation-delay: 1.2s; }
.strata .block:nth-of-type(3) { animation-delay: 2.4s; }
.strata .block:nth-of-type(4) { animation-delay: 3.6s; }
@keyframes blockOn { 0%, 10% { opacity: .25; } 20%, 70% { opacity: 1; } 100% { opacity: .25; } }
.strata .sensor-ring { transform-origin: 280px 262px; animation: pulse 2s ease-out infinite; }
.strata .layer { animation: float 8s ease-in-out infinite; }
.strata .layer:nth-of-type(2) { animation-delay: -2s; }
.strata .layer:nth-of-type(3) { animation-delay: -4s; }

.doors { display: grid; gap: 14px; grid-template-columns: repeat(auto-fit, minmax(min(100%, 180px), 1fr)); margin-top: 42px; }
.door {
  display: block; text-decoration: none; padding: 18px 20px; border-radius: 14px;
  background: rgba(255,255,255,.06); border: 1px solid rgba(255,255,255,.14); transition: background .25s, transform .25s var(--ease);
}
.door:hover { background: rgba(217,164,65,.16); transform: translateY(-3px); }
.door b { display: block; color: var(--accent); font-size: .8rem; letter-spacing: .12em; text-transform: uppercase; }
.door span { font-weight: 700; }

/* Observatoire : graphique illustratif */
.chart-card { background: #fff; border-radius: var(--radius); border: 1px solid var(--line); padding: 24px; box-shadow: var(--shadow); }
.chart-tabs { display: flex; flex-wrap: wrap; gap: 6px; margin-bottom: 18px; }
.chart-tabs button { border: 1px solid var(--line); background: var(--surface); border-radius: 999px; padding: 8px 14px; font-weight: 700; font-size: .88rem; min-height: 40px; }
.chart-tabs button[aria-pressed="true"] { background: var(--brand); color: #fff; border-color: var(--brand); }
.bars { display: grid; grid-template-columns: repeat(6, 1fr); gap: 12px; align-items: end; height: 220px; border-bottom: 2px solid var(--line); padding: 0 4px; }
.bar-group { display: flex; gap: 4px; align-items: end; height: 100%; }
.bar-group i { flex: 1; border-radius: 6px 6px 0 0; transform-origin: bottom; transform: scaleY(0); transition: transform 1s var(--ease), height .6s var(--ease); }
.bar-group i.m { background: var(--brand); }
.bar-group i.d { background: var(--accent); }
.chart-card.is-in .bar-group i { transform: scaleY(1); }
.bar-labels { display: grid; grid-template-columns: repeat(6, 1fr); gap: 12px; font-size: .78rem; color: var(--muted); text-align: center; margin-top: 8px; }
.legend { display: flex; flex-wrap: wrap; gap: 16px; font-size: .85rem; margin-top: 16px; color: var(--muted); }
.legend span::before { content: ""; display: inline-block; width: 12px; height: 12px; border-radius: 3px; margin-right: 6px; vertical-align: -1px; background: var(--brand); }
.legend span.d::before { background: var(--accent); }
.gap-note { margin-top: 12px; font-weight: 700; color: var(--brand); }

.layer-ico { font-weight: 800; font-size: .78rem; color: var(--accent); letter-spacing: .1em; }