@charset "utf-8";

* {
    margin: 0;
    padding: 0;
    list-style-type: none;
}
body{
    padding: 20px;
    box-sizing: border-box;
}

#game {
    border: 1px solid black;

}

h2 {
    text-align: center;
    margin-bottom: 20px;
}

.explain {
    font-size: 20px;
    color: #333;
    width: 500px;
    float: right;
}

.content-box {
    float: left;
}

@media only screen and (max-width:1200px) {
    .explain {
        float: left;
    }
}