.cell {
  border: 1px solid;
  height: 15px;
  width: 15px;
  display: inline-block;
  box-sizing: border-box;
  background-color: lightgray;
}
.cellRow .cell:not(:first-of-type) {
  border-left: 0;
}
.cellRow:not(:last-of-type) .cell {
  border-bottom: 0;
}
.cell.alive {
  background-color: yellow;
}
.cellRow {
  height: 15px;
  font-size: 0; /* removes whitespace between each cell */
}
.gameControlGroup {
  display: inline;
  margin: auto 0.5em;
  cursor: default;
}
#gameSpeed {
  width: 100px;
}
#board {
  margin: 1em;
  display: inline-block;
}

div#source-code {
  text-align: center;

  padding: 2em;
}
div#source-code img {
  width: 25px;
  height: 25px;
}
div#source-code a {
  color: #01579B;
  text-decoration: none;
}
div#source-code a:hover {
  text-decoration: underline;
}