.evidence-back-to-top {
  position: fixed;
  z-index: 120;
  right: clamp(16px, 2.5vw, 34px);
  bottom: clamp(16px, 2.5vw, 34px);
  width: 42px;
  height: 42px;
  display: grid;
  place-items: center;
  padding: 0;
  border: 1px solid rgba(42, 34, 26, 0.13);
  border-radius: 50%;
  background: rgba(255, 250, 242, 0.94);
  color: #2a221a;
  box-shadow:
    0 10px 24px -14px rgba(42, 27, 18, 0.72),
    inset 0 0 0 1px rgba(255, 255, 255, 0.58);
  -webkit-backdrop-filter: blur(8px);
  backdrop-filter: blur(8px);
  opacity: 0;
  transform: translateY(12px) scale(0.92);
  pointer-events: none;
  cursor: pointer;
  transition:
    opacity 0.2s ease,
    transform 0.2s ease,
    background 0.2s ease,
    color 0.2s ease;
}

.evidence-back-to-top span {
  display: block;
  width: 9px;
  height: 9px;
  border-top: 1.75px solid currentColor;
  border-left: 1.75px solid currentColor;
  transform: translateY(2px) rotate(45deg);
  transition: transform 0.2s ease;
}

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

.evidence-back-to-top:hover {
  background: var(--kz-coral, #e9744a);
  color: #fff;
  transform: translateY(-2px) scale(1);
}

.evidence-back-to-top:hover span {
  transform: translateY(-1px) rotate(45deg);
}

.evidence-back-to-top:focus-visible {
  outline: 3px solid rgba(233, 116, 74, 0.32);
  outline-offset: 3px;
}

@media (max-width: 640px) {
  .evidence-back-to-top {
    right: 14px;
    bottom: 14px;
    width: 38px;
    height: 38px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .evidence-back-to-top,
  .evidence-back-to-top span {
    transition: none;
  }
}