#shelf-container {
  background: url("../assets/shelf-bg.png");
  background-size: cover;
  width: 100%;
  height: 300px;
  border: 3px solid #c2b09a;
  border-radius: 10px;
  margin-top: 20px;
}

#shelf {
  position: relative;
  width: 100%;
  height: 100%;
  display: flex;
  align-items: flex-end;
  gap: 6px;
  padding: 20px;
}

.book {
  width: 40px;
  height: 200px;
  background-size: cover;
  background-position: center;
  cursor: grab;
  user-select: none;
  border-radius: 3px;
  transition: transform 0.1s;
}

.book:active {
  cursor: grabbing;
  transform: scale(1.05);
}

/* Modal */
#modal.hidden {
  display: none;
}

#modal {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.7);
  display: flex;
  justify-content: center;
  align-items: center;
}

#modal-content {
  background: #fff8ef;
  padding: 20px;
  width: 300px;
  border-radius: 10px;
  text-align: center;
  border: 3px solid #cdb8a1;
  position: relative;
}

#modal-cover {
  width: 100%;
  border-radius: 6px;
}

#close {
  position: absolute;
  top: 5px;
  right: 10px;
  cursor: pointer;
  font-size: 22px;
}