/* =========================
   스크롤 TOP 버튼 (PC + 모바일 공통)
   ========================= */

#scrollTopBtn{
  position: fixed;
  right: 18px;
  bottom: 24px;
  z-index: 999;

  width: 44px;
  height: 44px;
  border-radius: 50%;

  background: rgba(255,255,255,0.92);   /* 촌스러운 파랑 제거 */
  color: rgba(15,23,42,0.75);

  border: 1px solid rgba(226,232,240,0.9);
  box-shadow: 0 8px 18px rgba(15,23,42,0.12);

  display: flex;
  align-items: center;
  justify-content: center;

  font-size: 18px;
  font-weight: 700;
  cursor: pointer;

  opacity: 0;
  pointer-events: none;
  transform: translateY(6px);
  transition: opacity .2s ease, transform .2s ease,
  box-shadow .2s ease, background .2s ease;
}

#scrollTopBtn.show{
  opacity: 1;
  pointer-events: auto;
  transform: translateY(0);
}

#scrollTopBtn:hover{
  background: rgba(241,245,249,1);
  color: rgba(15,23,42,0.9);
  box-shadow: 0 10px 22px rgba(15,23,42,0.16);
}