body,
html {
  height: 100%;
  margin: 0;
  display: flex;
  justify-content: center;
  align-items: center;
  background-color: #f0f0f0;
}

#app {
  display: flex;
  flex-direction: column;
  align-items: center;
}

.grid {
  display: grid;
  grid-template-columns: repeat(16, 2rem);
  grid-gap: 5px;
  margin-bottom: 1rem;
}


.cell {
  width: 2rem;
  height: 2rem;
  background-color: #fff;
  border: 1px solid #ddd;
  cursor: pointer;
}

.toolbox {
  display: flex;
  gap: 1rem;
}