* {
  box-sizing: border-box;
}

body {
  display: grid;
  place-content: center;
  grid-template-columns: repeat(auto-fit, 150px);
  gap: 20px;
  min-height: 100vh;
  margin: 0;
  background: #eee;
}

.box {
  width: 150px;
  height: 150px;
  border: 3px solid black;
  background-color: white;
}

.fill {
  width: 144px;
  height: 144px;
  background-image: url("https://picsum.photos/200");
  cursor: grab;
}

.hold {
  border: 3px solid #ccc;
}

.hovered {
  background-color: #333;
}