.back-to-top {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  width: 50px;
  height: 50px;
  background: linear-gradient(135deg, #000000 0%, #333333 100%);
  color: #ffffff;
  border: none;
  border-radius: 50%;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
  opacity: 0;
  visibility: hidden;
  transform: translateY(100px);
  transition: transform 0.3s cubic-bezier(0.34, 1.56, 0.64, 1), opacity 0.3s ease;
  will-change: transform, opacity;
  z-index: 9999;
  padding: 0;
}

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

.back-to-top:hover {
  background: linear-gradient(135deg, #333333 0%, #000000 100%);
  transform: translateY(-5px);
  box-shadow: 0 6px 20px rgba(0, 0, 0, 0.4);
}

.back-to-top svg {
  width: 24px;
  height: 24px;
  transition: transform 0.3s ease;
}

.back-to-top:hover svg {
  transform: translateY(-3px);
}

.back-to-top:active {
  transform: translateY(-2px);
  box-shadow: 0 3px 10px rgba(0, 0, 0, 0.3);
}

@media (max-width: 767px) {
  .back-to-top {
    width: 45px;
    height: 45px;
    bottom: 1.5rem;
    right: 1.5rem;
  }

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

@media (min-width: 768px) and (max-width: 1023px) {
  .back-to-top {
    width: 48px;
    height: 48px;
  }

  .back-to-top svg {
    width: 22px;
    height: 22px;
  }
}