* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}
#area {
  font: normal 20 px Arial;
  background: red;
  color: white;
  width: 150px;
  height: 150px;
  line-height: 150px;
  text-align: center;
}

.grid {
  display: grid;
  grid-template-columns: repeat(3, 150px);
  grid-template-rows: repeat(3, 150px);
  column-gap: 2px;
  gap: 2px;
}

body {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 24px;
  flex-direction: column;
  min-height: 100vh;
}

button {
  position: absolute;
  left: 50%;
  top: 50%;
  translate: -50% -50%;

}

button.hidden {
  opacity: 0;
  pointer-events: none;
}