.wrap{
    display: flex;
}
.list_board{
    display: block;
    float: left;
    width: 20%;
}
.board_btn{
    display: block;
    height: 50px;
    text-align: center;
    padding-top: 12px;
    padding-bottom: 10px;
    border-style: none;
    text-decoration: none;
    background-color: #F8F9FA;
    color: black;
}

.board_btn:link{
    background-color: #F8F9FA;
}
.board_btn:visited{
    background-color: #F8F9FA;
}
.board_btn:hover{
    color: black;
    background-color: #e0e0e0;
}