.back {
    position: relative;
    width:700px;
    height:550px;
    background-color: #ccc;
    margin: 0 auto;
    padding-top: 50px;
}
.main {
    width:600px;
    height:400px;
    background-color: #00CC00;
    margin: 0 auto;
}

.info {
    position: absolute;
    width:200px;
    height: 100px;
    background-color: #00CC00;
    top:470px;
    left:50px;
}
.info p {
    margin: 0 20px;
    line-height: 50px;
    font-size: 25px;
    font-weight: bold;
}
.info p span {
    color:red;
}

.main div {
    width:23px;
    height:23px;
    border: 1px solid #727272;
    float:left;
}
.null {
    background-color: #cccedb;
}
.wall {
    background-color: #7f7f7f;
}
.cur {
    background-color: #f00;
}
.head {
    background-color: blue;
}
.target {
    background-color: yellow;
}