/* ==========================================================================
   004 — Shimmer Button · boutons
   Bouton premium : bordure en dégradé (double background padding-box /
   border-box), reflet diagonal qui balaye la surface (avec un temps mort
   entre deux passages), glow pulsant discret derrière le bouton. Le survol
   intensifie reflet + glow et soulève légèrement le bouton.
   ========================================================================== */

.shimmer-btn {
  --shimmer-btn-accent: var(--ml-accent, #7c8cff);
  --shimmer-btn-accent-2: var(--ml-accent-2, #2dd4bf);
  --shimmer-btn-sheen: color-mix(in srgb, var(--ml-fg, #e8eaf2) 20%, transparent);
  --shimmer-btn-sheen-soft: color-mix(in srgb, var(--ml-fg, #e8eaf2) 7%, transparent);

  position: relative;
  isolation: isolate; /* garde le glow (z-index:-1) sous le bouton, pas sous la page */
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 1.1rem 2.7rem;
  border: 1px solid transparent;
  border-radius: 999px;
  background:
    linear-gradient(var(--ml-surface, #151a24), var(--ml-surface, #151a24)) padding-box,
    linear-gradient(
      135deg,
      color-mix(in srgb, var(--shimmer-btn-accent) 80%, transparent),
      color-mix(in srgb, var(--shimmer-btn-accent-2) 65%, transparent)
    ) border-box;
  color: var(--ml-fg, #e8eaf2);
  font-family: inherit;
  font-size: 0.95rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  line-height: 1;
  cursor: pointer;
  -webkit-tap-highlight-color: transparent;
  transition:
    transform 0.45s cubic-bezier(0.22, 1, 0.36, 1),
    box-shadow 0.45s cubic-bezier(0.22, 1, 0.36, 1);
}

.shimmer-btn:hover,
.shimmer-btn:focus-visible {
  transform: translateY(-2px);
  box-shadow: 0 16px 42px -16px color-mix(in srgb, var(--shimmer-btn-accent) 55%, transparent);
}

.shimmer-btn:focus-visible {
  outline: 2px solid var(--ml-accent-2, #2dd4bf);
  outline-offset: 3px;
}

.shimmer-btn:active {
  transform: translateY(0) scale(0.99);
}

/* --- Glow pulsant (derrière le bouton) ------------------------------------ */

.shimmer-btn__glow {
  position: absolute;
  inset: 2px;
  z-index: -1;
  border-radius: inherit;
  background: linear-gradient(135deg, var(--shimmer-btn-accent), var(--shimmer-btn-accent-2));
  filter: blur(14px);
  opacity: 0.22;
  pointer-events: none;
  animation: shimmer-btn-pulse 3.8s ease-in-out infinite;
}

.shimmer-btn:hover .shimmer-btn__glow,
.shimmer-btn:focus-visible .shimmer-btn__glow {
  animation: none;
  opacity: 0.5;
  transition: opacity 0.5s ease;
}

/* --- Reflet diagonal --------------------------------------------------------
   __shine sert de masque (overflow hidden) ; son ::before est la bande de
   lumière translatée. Seuls transform et opacity sont animés. */

.shimmer-btn__shine {
  position: absolute;
  inset: 0;
  border-radius: inherit;
  overflow: hidden;
  opacity: 0.55;
  pointer-events: none;
  transition: opacity 0.4s ease;
}

.shimmer-btn:hover .shimmer-btn__shine,
.shimmer-btn:focus-visible .shimmer-btn__shine {
  opacity: 1;
}

.shimmer-btn__shine::before {
  content: "";
  position: absolute;
  inset: -1px;
  background: linear-gradient(
    115deg,
    transparent 32%,
    var(--shimmer-btn-sheen-soft) 44%,
    var(--shimmer-btn-sheen) 50%,
    var(--shimmer-btn-sheen-soft) 56%,
    transparent 68%
  );
  transform: translateX(-110%);
  animation: shimmer-btn-sweep 2.8s cubic-bezier(0.55, 0.09, 0.32, 1) infinite;
}

/* --- Label ------------------------------------------------------------------ */

.shimmer-btn__label {
  position: relative;
}

/* --- Wrapper de démo (galerie) ----------------------------------------------- */

.shimmer-btn-demo {
  display: flex;
  flex-direction: column;
  align-items: center;
}

/* --- Keyframes ---------------------------------------------------------------- */

@keyframes shimmer-btn-sweep {
  0%   { transform: translateX(-110%); }
  46%  { transform: translateX(110%); }
  100% { transform: translateX(110%); } /* temps mort entre deux passages */
}

@keyframes shimmer-btn-pulse {
  0%, 100% { opacity: 0.16; }
  50%      { opacity: 0.32; }
}

/* --- Accessibilité -------------------------------------------------------------- */

@media (prefers-reduced-motion: reduce) {
  .shimmer-btn__shine::before {
    animation: none;
    transform: translateX(0);
    opacity: 0.35; /* sheen statique discret, plus de balayage */
  }

  .shimmer-btn__glow {
    animation: none;
  }

  .shimmer-btn:hover,
  .shimmer-btn:focus-visible {
    transform: none;
  }
}