/* ── Back to Top Button ───────────────────────────────────────────────────── */

.dcr-back-top {
  position: fixed;
  right: calc(var(--sp-6) + 7px); /* 31px — centers with 56px chat bubble at right:24px */
  bottom: calc(var(--sp-6) + 56px + 10px); /* above 56px chat bubble + 10px gap */
  z-index: 8999;                /* just below chat (9000) */
  width: 42px;
  height: 42px;
  border-radius: var(--radius-full);
  background: var(--av-teal);
  border: none;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 4px 16px rgba(0, 150, 136, 0.35);
  opacity: 0;
  transform: translateY(8px);
  transition: opacity 0.22s ease, transform 0.22s ease, background 0.15s;
  pointer-events: none;
}
.dcr-back-top.visible {
  opacity: 1;
  transform: translateY(0);
  pointer-events: auto;
}
.dcr-back-top:hover {
  background: var(--teal-mid);
  transform: translateY(-2px);
}
.dcr-back-top:focus-visible {
  outline: 2px solid var(--blue);
  outline-offset: 3px;
}
.dcr-back-top svg {
  width: 18px;
  height: 18px;
  stroke: var(--white);
  fill: none;
  stroke-width: 2.5;
  stroke-linecap: round;
  stroke-linejoin: round;
}

@media (max-width: 480px) {
  .dcr-back-top {
    right: calc(var(--sp-4) + 9px); /* 25px — centers with 56px chat at right:16px */
    bottom: calc(var(--sp-4) + 56px + 10px);
    width: 38px;
    height: 38px;
  }
}
@media (prefers-reduced-motion: reduce) {
  .dcr-back-top { transition: none; }
}