.back-to-top {
  position: fixed;
  right: 24px;
  bottom: 24px;
  z-index: 90;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 42px;
  height: 42px;
  border: 1px solid var(--gray-200);
  border-radius: 50%;
  background: var(--white);
  color: var(--navy);
  box-shadow: var(--shadow-md);
  cursor: pointer;
  transition: background 0.2s, color 0.2s, transform 0.2s;
}

.back-to-top[hidden] {
  display: none;
}

.back-to-top:hover {
  background: var(--navy);
  color: var(--white);
  transform: translateY(-2px);
}

.back-to-top:focus-visible {
  outline: 3px solid rgba(37, 99, 235, 0.2);
  outline-offset: 2px;
}