/* WhatsApp — botão vertical encostado à esquerda */

.whatsapp-float {
  position: fixed;
  left: 0;
  top: 50%;
  z-index: 120;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 9.5rem;
  padding: 0.95rem 0.65rem;
  border-radius: 0 14px 14px 0;
  background: linear-gradient(180deg, #25d366 0%, #128c7e 100%);
  color: #fff;
  text-decoration: none;
  box-shadow:
    4px 0 20px rgba(18, 140, 126, 0.4),
    0 0 0 1px rgba(255, 255, 255, 0.1);
  transform: translateY(-50%);
  transition:
    transform 0.25s var(--ease),
    box-shadow 0.25s var(--ease),
    filter 0.25s,
    padding 0.25s var(--ease);
}

.whatsapp-float:hover {
  filter: brightness(1.06);
  padding-right: 0.8rem;
  box-shadow:
    6px 0 28px rgba(18, 140, 126, 0.5),
    0 0 0 1px rgba(255, 255, 255, 0.16);
}

.whatsapp-float__label {
  writing-mode: vertical-rl;
  transform: rotate(180deg);
  font-family: var(--font-display);
  font-size: 0.82rem;
  font-weight: 700;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  line-height: 1;
}

body.lesson-preview-open .whatsapp-float {
  opacity: 0;
  pointer-events: none;
}

@media (max-width: 640px) {
  .whatsapp-float {
    min-height: 8.25rem;
    padding: 0.8rem 0.55rem;
  }

  .whatsapp-float__label {
    font-size: 0.74rem;
  }
}

@media (prefers-reduced-motion: reduce) {
  .whatsapp-float {
    transition: none;
  }
}