/* スクロールトップボタン - 全画面対応 */
#scrollTopBtn {
  position: fixed;
  bottom: 30px;
  right: 30px;
  width: 60px;
  height: 60px;
  background: #002f6c;
  color: white;
  border: none;
  border-radius: 50%;
  font-size: 28px;
  display: none;
  cursor: pointer;
  align-items: center;
  justify-content: center;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.4);
  z-index: 10000;
  transition: all 0.3s ease;
  opacity: 0.9;
}

#scrollTopBtn:hover {
  background: #005bb5;
  transform: scale(1.1);
  opacity: 1;
  box-shadow: 0 6px 16px rgba(0, 0, 0, 0.5);
}

#scrollTopBtn:active {
  transform: scale(0.95);
}