.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  font-weight: 700;
  font-size: var(--fs-sm);
  padding: 0.95rem 1.7rem;
  border-radius: var(--radius-pill);
  transition: transform var(--dur-fast) var(--ease-out), box-shadow var(--dur-fast) var(--ease-out),
    background var(--dur-fast) var(--ease-out);
  white-space: nowrap;
}

.btn svg {
  width: 1.1em;
  height: 1.1em;
  flex-shrink: 0;
}

.btn--cta {
  background: var(--color-cta);
  color: var(--white);
  box-shadow: 0 10px 24px -8px rgba(217, 86, 42, 0.55);
}

.btn--cta:hover {
  background: var(--color-cta-hover);
  transform: translateY(-2px);
  box-shadow: 0 16px 32px -10px rgba(217, 86, 42, 0.6);
}

.btn--ghost {
  background: transparent;
  color: var(--white);
  border: 1.5px solid rgba(255, 255, 255, 0.55);
}

.btn--ghost:hover {
  background: rgba(255, 255, 255, 0.12);
  transform: translateY(-2px);
}

.btn--dark {
  background: var(--ink-900);
  color: var(--cream-50);
}

.btn--dark:hover {
  background: var(--green-800);
  transform: translateY(-2px);
}

.btn--sm {
  padding: 0.7rem 1.3rem;
  font-size: var(--fs-xs);
}

.btn--block {
  width: 100%;
  justify-content: center;
}

.btn:active {
  transform: translateY(0);
}

/* Floating WhatsApp action, present on every section */
.whatsapp-fab {
  position: fixed;
  right: var(--sp-4);
  bottom: var(--sp-4);
  z-index: 90;
  width: 60px;
  height: 60px;
  border-radius: 50%;
  background: #25d366;
  display: grid;
  place-items: center;
  box-shadow: var(--shadow-lg);
  transition: transform var(--dur-fast) var(--ease-out);
}

.whatsapp-fab:hover {
  transform: scale(1.08);
}

.whatsapp-fab svg {
  width: 30px;
  height: 30px;
  fill: var(--white);
}

.whatsapp-fab__ping {
  position: absolute;
  inset: 0;
  border-radius: 50%;
  background: #25d366;
  animation: ping 2.6s cubic-bezier(0, 0, 0.2, 1) infinite;
}

@keyframes ping {
  0% {
    opacity: 0.55;
    transform: scale(1);
  }
  100% {
    opacity: 0;
    transform: scale(1.7);
  }
}

@media (prefers-reduced-motion: reduce) {
  .whatsapp-fab__ping {
    animation: none;
    display: none;
  }
}

/* Botón flotante "volver arriba" — lado opuesto al de WhatsApp para no
   competir con él, oculto hasta que el usuario baja lo suficiente. */
.back-to-top {
  position: fixed;
  left: var(--sp-4);
  bottom: var(--sp-4);
  z-index: 90;
  width: 46px;
  height: 46px;
  border-radius: 50%;
  background: var(--ink-900);
  color: var(--white);
  display: grid;
  place-items: center;
  box-shadow: var(--shadow-md);
  opacity: 0;
  transform: translateY(12px);
  visibility: hidden;
  pointer-events: none;
  transition: opacity var(--dur-fast) var(--ease-out), transform var(--dur-fast) var(--ease-out),
    visibility var(--dur-fast) var(--ease-out), background var(--dur-fast) var(--ease-out);
}

.back-to-top.is-visible {
  opacity: 1;
  transform: translateY(0);
  visibility: visible;
  pointer-events: auto;
}

.back-to-top:hover {
  background: var(--green-700);
}

.back-to-top svg {
  width: 20px;
  height: 20px;
  stroke: currentColor;
}