button { width:22px; height:22px; background-color:white; border-width:1px; }
p      {             height:8px;                                            }

.give  { color:black; border-color:black; }
.null  { color:white; border-style:none;  }

.sink { color:red;    border-color:red;              }
.sour { color:red;    border-color:red; display:none }

#lett { color:black;  border-color:black; width:36px; height:36px; border-width:2px; display:none; }
#numb { color:black;  border-color:black; width:36px; height:36px; border-width:2px; display:none; }

.sink:hover,  .sour:hover  {              background-color:yellow; }
.sink:active, .sour:active { color:white; background-color:red;    }

h1 {
  font: 36px/0px Courier, monospace;
  color: yellow;
  text-shadow: 0 0 18px #FF0000, 0 0 36px #0000FF;
}