body {
  background-color: lightgrey;
}

.grid {
  display: grid;
  grid-gap: 10px;
}

.center {
  margin: auto;
  padding: 10px;
  position: absolute;
  top: 60%;
  left: 50%;
  transform: translate(-50%, -60%);  
}

.cell-template {
  display: none;
}

.grid > div {
  padding: 0px;
  text-align: center;
}

.grid > div > button {
  width: 100%;
  height: 100%;
  padding: 0px;
  border-radius: 0;
  -webkit-border-radius:0;
  -webkit-appearance:none;

  /* border-width: 0px */
  /* font-size: 18pt; */
}

.grid > div > button > img {
  width: 100%;
  height: 100%;
  padding: 0px;
  /* border-width: 0px */
  /* font-size: 18pt; */
}

.grid > div > span {
  font-family: sans-serif;
  font-size: 60px;
  color: white;
  background-color: inherit;
  position: relative;
  top: -33%;
  text-shadow: black 3px 3px;
}

.selected {
  border: blue 4px solid;
}

#menu {
  display: flex;
  gap: 30px;
}

#menu button {
  flex-grow: 1;
  font-size: 2em;
}

#help {
  text-align: center;
  position: relative;
  background-color: rgba(255, 255, 255, 0.489);
}

#help * {
  font-family: sans-serif;
  font-size: 40px;
  padding: 15px;
}