/* =========================================================
   BOTÃO "VOLTAR AO TOPO"
   Fixo no canto inferior direito, empilhado logo ACIMA do
   botão de WhatsApp e centralizado com ele. Aparece só depois
   que a pessoa rola a página, com fade + leve subida.
========================================================= */

.back-to-top {
  position: fixed;
  right: 29px;   /* centraliza com o whatsapp (right:20px, 52px de largura) */
  bottom: 172px;
  z-index: 9999;

  display: flex;
  align-items: center;
  justify-content: center;

  width: 34px;
  height: 34px;
  border-radius: 50%;

  background-color: var(--navy-900, #0b0f1e);
  border: 1px solid var(--gold, #c9962c);
  color: var(--gold, #c9962c);

  cursor: pointer;
  text-decoration: none;

  /* remove o retângulo cinza/quadrado que o Chrome/Safari mobile
     desenham automaticamente ao tocar em um elemento clicável */
  -webkit-tap-highlight-color: transparent;

  box-shadow: 0 3px 10px rgba(0, 0, 0, 0.25);

  /* escondido por padrão: só aparece depois de rolar a página
     (classe .is-visible controlada via JS) */
  opacity: 0;
  visibility: hidden;
  translate: 0 12px;
  pointer-events: none;

  transition: opacity 0.35s ease, translate 0.35s ease,
    visibility 0s linear 0.35s, box-shadow 0.45s ease,
    scale 0.45s cubic-bezier(0.16, 1, 0.3, 1),
    background-color 0.35s ease, color 0.35s ease;
}

.back-to-top.is-visible {
  opacity: 1;
  visibility: visible;
  translate: 0 0;
  pointer-events: auto;
  transition: opacity 0.35s ease, translate 0.35s ease,
    visibility 0s linear 0s, box-shadow 0.45s ease,
    scale 0.45s cubic-bezier(0.16, 1, 0.3, 1),
    background-color 0.35s ease, color 0.35s ease;
}

.back-to-top:hover {
  background-color: var(--gold, #c9962c);
  color: var(--navy-950, #0a0f1c);
  scale: 1.05;
  box-shadow: 0 6px 18px rgba(201, 150, 44, 0.35);
}

.back-to-top:hover svg {
  transform: translateY(-1px);
}

.back-to-top:active {
  scale: 0.96;
}

.back-to-top:focus-visible {
  outline: 2px solid rgba(255, 255, 255, 0.7);
  outline-offset: 3px;
}

.back-to-top svg {
  width: 14px;
  height: 14px;
  pointer-events: none;
  transition: transform 0.45s cubic-bezier(0.16, 1, 0.3, 1);
}

@media (prefers-reduced-motion: reduce) {
  .back-to-top {
    transition: opacity 0.2s ease, visibility 0s linear 0.2s;
  }
  .back-to-top.is-visible {
    transition: opacity 0.2s ease, visibility 0s linear 0s;
  }
  .back-to-top:hover {
    scale: 1;
  }
}

/* ---- mobile: reduz tamanho e distância das bordas,
   centralizado com o whatsapp (right:14px, 46px de largura) ---- */
@media (max-width: 480px) {
  .back-to-top {
    right: 22px;
    bottom: 138px;
    width: 30px;
    height: 30px;
  }

  .back-to-top svg {
    width: 12px;
    height: 12px;
  }
}