.btn-volver {
  position: fixed;
  top: 35px;
  left: 15px;

  width: 45px;
  height: 45px;

  background: #e67e22;
  color: white;

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

  border-radius: 50%;
  font-size: 18px;
  cursor: pointer;

  box-shadow: 0 4px 10px rgba(0,0,0,0.3);
  z-index: 2000;

  transition: transform 0.2s, box-shadow 0.2s;

  /* 🔥 BLINDAJE CONTRA OTROS CSS */
  padding: 0 !important;
  box-sizing: content-box !important;
  line-height: 1 !important;
  overflow: hidden;
}

/* efecto hover */
.btn-volver:hover {
  transform: scale(1.1);
  box-shadow: 0 6px 14px rgba(0,0,0,0.4);
}

/* efecto click */
.btn-volver:active {
  transform: scale(0.95);
}

/* 📱 mobile */
@media (max-width: 500px) {
  .btn-volver {
    width: 40px !important;
    height: 40px !important;
    font-size: 16px;
    top: 10px;
    left: 10px;
  }
}

/* CELULAR */
@media (max-width:768px){
  .btn-volver{
      position:fixed;
      top:10px;
      left:10px;
      margin:0;
      z-index:9999;
      box-shadow:0 3px 6px rgba(0,0,0,0.3);
  }
}