body{
  margin:0;
  background:white;
  font-family:Arial;
  text-align:center;
}

h1{
  margin-top:20px;
}

.grid{
  width:1000px;
  height:1000px;
  margin:30px auto;
  display:grid;
  grid-template-columns:repeat(100,1fr);
  gap:1px;
  background:#ddd;
  padding:10px;
  border-radius:20px;
}

.pixel{
  background:white;
  aspect-ratio:1/1;
  border-radius:3px;
  transition:0.2s;
}

.pixel:hover{
  background:#4da6ff;
}