/* ==========================================================================
   001 — Liquid Button · boutons
   Remplissage liquide gooey au survol : des gouttes montent, fusionnent en
   metaballs (filtre SVG #goo-liquid-button, fourni par snippet.html), puis
   la nappe inonde le bouton et le label bascule en couleur contrastée.
   Dépendance : le <svg> de defs du snippet DOIT être présent dans la page.
   ========================================================================== */

.liquid-btn {
  --liquid-btn-fill: var(--ml-accent, #7c8cff);
  --liquid-btn-ink: var(--ml-fg, #e8eaf2);
  --liquid-btn-ink-flood: var(--ml-bg, #0d1017);
  --liquid-btn-ease-out: cubic-bezier(0.22, 1, 0.36, 1);
  --liquid-btn-ease-in: cubic-bezier(0.55, 0, 0.68, 0.19);
  --liquid-btn-ease-splash: cubic-bezier(0.3, 1.25, 0.42, 1);

  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 1.05rem 2.6rem;
  border: 0;
  border-radius: 999px;
  background: transparent;
  color: var(--liquid-btn-ink);
  font-family: inherit;
  font-size: 0.95rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  line-height: 1;
  cursor: pointer;
  -webkit-tap-highlight-color: transparent;
  box-shadow:
    inset 0 0 0 1px color-mix(in srgb, var(--liquid-btn-fill) 50%, transparent),
    0 0 0 0 transparent;
  transition:
    box-shadow 0.6s var(--liquid-btn-ease-out),
    transform 0.2s ease;
}

.liquid-btn:hover,
.liquid-btn:focus-visible {
  box-shadow:
    inset 0 0 0 1px color-mix(in srgb, var(--liquid-btn-fill) 90%, transparent),
    0 14px 38px -12px color-mix(in srgb, var(--liquid-btn-fill) 60%, transparent);
}

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

.liquid-btn:active {
  transform: scale(0.98);
}

/* --- Couche liquide — le filtre goo fusionne gouttes et nappe ------------ */

.liquid-btn__liquid {
  position: absolute;
  inset: 0;
  border-radius: inherit;
  overflow: hidden;
  filter: url(#goo-liquid-button);
  pointer-events: none;
}

/* Gouttes : chacune part du dessous avec sa taille, sa position, son retard */
.liquid-btn__blob {
  position: absolute;
  bottom: -1.2rem;
  width: 2.4rem;
  height: 2.4rem;
  border-radius: 50%;
  background: var(--liquid-btn-fill);
  transform: translate3d(0, 170%, 0) scale(0.5);
  transition: transform 0.45s var(--liquid-btn-ease-in);
}

.liquid-btn__blob:nth-child(1) { left: 6%;  width: 2.1rem; height: 2.1rem; }
.liquid-btn__blob:nth-child(2) { left: 24%; width: 2.7rem; height: 2.7rem; }
.liquid-btn__blob:nth-child(3) { left: 45%; width: 2.2rem; height: 2.2rem; }
.liquid-btn__blob:nth-child(4) { left: 63%; width: 2.9rem; height: 2.9rem; }
.liquid-btn__blob:nth-child(5) { left: 82%; width: 2.3rem; height: 2.3rem; }

.liquid-btn:hover .liquid-btn__blob,
.liquid-btn:focus-visible .liquid-btn__blob {
  transition: transform 0.75s var(--liquid-btn-ease-splash);
}

.liquid-btn:hover .liquid-btn__blob:nth-child(1),
.liquid-btn:focus-visible .liquid-btn__blob:nth-child(1) { transform: translate3d(0, -60%, 0) scale(1);    transition-delay: 0.02s; }
.liquid-btn:hover .liquid-btn__blob:nth-child(2),
.liquid-btn:focus-visible .liquid-btn__blob:nth-child(2) { transform: translate3d(0, -115%, 0) scale(1.05); transition-delay: 0.09s; }
.liquid-btn:hover .liquid-btn__blob:nth-child(3),
.liquid-btn:focus-visible .liquid-btn__blob:nth-child(3) { transform: translate3d(0, -80%, 0) scale(0.95);  transition-delay: 0s; }
.liquid-btn:hover .liquid-btn__blob:nth-child(4),
.liquid-btn:focus-visible .liquid-btn__blob:nth-child(4) { transform: translate3d(0, -125%, 0) scale(1.08); transition-delay: 0.12s; }
.liquid-btn:hover .liquid-btn__blob:nth-child(5),
.liquid-btn:focus-visible .liquid-btn__blob:nth-child(5) { transform: translate3d(0, -70%, 0) scale(1);     transition-delay: 0.05s; }

/* Nappe : la surface du liquide qui monte derrière les gouttes */
.liquid-btn__pool {
  position: absolute;
  left: -12%;
  right: -12%;
  bottom: -20%;
  height: 150%;
  border-radius: 42% 38% 0 0 / 2.4rem 1.9rem 0 0;
  background: var(--liquid-btn-fill);
  transform: translate3d(0, 108%, 0);
  transition: transform 0.5s var(--liquid-btn-ease-in);
}

.liquid-btn:hover .liquid-btn__pool,
.liquid-btn:focus-visible .liquid-btn__pool {
  transform: translate3d(0, 8%, 0);
  transition: transform 0.85s var(--liquid-btn-ease-out) 0.15s;
}

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

.liquid-btn__label {
  position: relative;
  z-index: 1;
  transition: color 0.25s ease-out;
}

.liquid-btn:hover .liquid-btn__label,
.liquid-btn:focus-visible .liquid-btn__label {
  color: var(--liquid-btn-ink-flood);
  transition: color 0.3s ease-out 0.3s;
}

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

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

.liquid-btn-defs {
  position: absolute;
  width: 0;
  height: 0;
  overflow: hidden;
}

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

@media (prefers-reduced-motion: reduce) {
  .liquid-btn__blob {
    display: none;
  }

  .liquid-btn__liquid {
    filter: none;
  }

  .liquid-btn__pool {
    inset: 0;
    height: auto;
    border-radius: inherit;
    transform: none;
    opacity: 0;
    transition: opacity 0.25s ease-out;
  }

  .liquid-btn:hover .liquid-btn__pool,
  .liquid-btn:focus-visible .liquid-btn__pool {
    transform: none;
    opacity: 1;
    transition: opacity 0.25s ease-out;
  }

  .liquid-btn:hover .liquid-btn__label,
  .liquid-btn:focus-visible .liquid-btn__label {
    transition-delay: 0s;
  }
}