body {font-family: 'Kosugi Maru', sans-serif; /*margin : 50px*/ ;/*background-color: #ffff7f;*/}

a {color: #0080ff;
text-decoration: none;}

div   { text-align:left;}

.tree {
    /*margin-top:10px;
    margin-left:5px;
    float:left;
    background-color:  #ccc;*/
}

summary{
    margin-left:30px;
}

details{
    margin-left:30px;
}
.details_content {
    margin-left:60px;
}