* { 
  box-sizing: border-box;  
  font-family: sans-serif;
}
body {
  background: #b00;
}
.details {
  display:flex;
  flex-wrap:wrap;
  justify-content: center;
  align-items: center;
  text-align: center;
  gap:1px;
}
.charmap {
  width: 45px;
  font-family: sans-serif;
  text-align: center;
  border:1px solid #999;
  text-shadow:1px 1px #777;
 
}
.charmap:nth-child(odd) {
  background: #ddd;
}
.charmap:nth-child(even) {
  background: #fff;
}

.i {
  border:1px solid #999;
  font-size: 0.65rem;
  color:white;
  display: block;
  background: red;
  width: 25px;
  border-radius:5px;
  text-align: center;
  text-shadow:1px 1px #777;
  cursor: pointer;
}
.ascii {
/*   border:1px solid #999; */
  width: 60px;
}
h1 {
  text-align: center;
  color:white;
  text-shadow:2px 1px #777;

}
.btn {
  font-size: 0.75rem;
}

.btn.active {
  background: #444;
  color:#eee;
}