/*
  MVB · Carbon Aura (opção inspirada no cartão C6)
  ------------------------------------------------
  Degradê slate-matte com sheen diagonial metálico.
  Mantém ouro MVB como acento patrimonial; prata fria
  como reflexo institucional (não substitui A/B/C).

  Uso: linkar só no Modelo D.
  Classes: .carbon-sheen · .carbon-band · .carbon-wash
*/

:root {
  --carbon: #141c26;
  --carbon-mid: #243344;
  --carbon-lift: #3a4f66;
  --carbon-mist: #5a6f88;
  --carbon-silver: #d4dbe4;
  --carbon-gold: #c7a16a;
  --carbon-gold-bright: #e2d0a8;
  --carbon-paper: #f1f0ed;
  --carbon-ink: #151a22;
}

/* Faixa escura com o mesmo “matte metal” do cartão */
.carbon-band {
  position: relative;
  isolation: isolate;
  overflow: hidden;
  background:
    linear-gradient(
      128deg,
      rgba(90, 111, 136, 0.42) 0%,
      rgba(58, 79, 102, 0.12) 28%,
      transparent 48%,
      rgba(20, 28, 38, 0.55) 100%
    ),
    linear-gradient(155deg, #2f4156 0%, var(--carbon-mid) 42%, var(--carbon) 78%, #0d1218 100%);
}

.carbon-band::before {
  content: "";
  position: absolute;
  inset: -20%;
  z-index: 0;
  pointer-events: none;
  background:
    linear-gradient(
      125deg,
      transparent 18%,
      rgba(212, 219, 228, 0.09) 42%,
      transparent 58%
    ),
    radial-gradient(ellipse 55% 50% at 18% 20%, rgba(199, 161, 106, 0.16), transparent 58%),
    radial-gradient(ellipse 45% 40% at 88% 70%, rgba(90, 111, 136, 0.22), transparent 60%);
  animation: carbon-sheen-drift 22s ease-in-out infinite alternate;
}

.carbon-band > * {
  position: relative;
  z-index: 1;
}

/* Sheen diagonal sutil (hero wash / overlays) */
.carbon-sheen {
  background:
    linear-gradient(
      105deg,
      rgba(20, 28, 38, 0.94) 0%,
      rgba(36, 51, 68, 0.88) 34%,
      rgba(58, 79, 102, 0.42) 62%,
      rgba(20, 28, 38, 0.72) 100%
    );
}

.carbon-sheen--deep {
  background:
    linear-gradient(
      112deg,
      rgba(13, 18, 24, 0.96) 0%,
      rgba(26, 38, 52, 0.9) 38%,
      rgba(74, 94, 118, 0.38) 68%,
      rgba(20, 28, 38, 0.78) 100%
    );
}

/* Wash claro com frio do slate (seções papel) */
.carbon-wash {
  position: relative;
  isolation: isolate;
  background:
    radial-gradient(ellipse 70% 50% at 8% 0%, rgba(90, 111, 136, 0.08), transparent 55%),
    radial-gradient(ellipse 55% 45% at 95% 20%, rgba(199, 161, 106, 0.06), transparent 50%),
    linear-gradient(180deg, #eceff2 0%, var(--carbon-paper) 42%, #f6f5f2 100%);
}

@keyframes carbon-sheen-drift {
  from { transform: translate3d(0, 0, 0) scale(1); }
  to   { transform: translate3d(-1.8%, 1.4%, 0) scale(1.04); }
}

@media (prefers-reduced-motion: reduce) {
  .carbon-band::before {
    animation: none !important;
    transform: none;
  }
}