.game-tip {
  height: 60px; }

.content, #background table .food:before, #snake li:before {
  content: '';
  position: absolute;
  left: 10px;
  right: 10px;
  top: 10px;
  bottom: 10px; }

#background {
  position: relative;
  margin: 10px auto;
  width: 660px;
  height: 660px; }
  #background table td {
    position: relative;
    width: 60px;
    height: 60px;
    border: 1px solid #1EEDFF;
    box-sizing: border-box; }
  #background table .food:before {
    background: #4EA9F3; }

#snake li {
  list-style: none;
  position: absolute;
  width: 60px;
  height: 60px;
  box-sizing: border-box; }
  #snake li:before {
    background: #ccc; }
  #snake li:first-child::before {
    background-color: yellowgreen; }
  #snake li:last-child::before {
    background-color: tomato; }