.container{

    width: 100%;

    display: flex;

    flex-flow: row wrap;

    justify-content: space-around;

}

.block{
    
    box-sizing: border-box;
    -ms-box-sizing: border-box;
    -moz-box-sizing: border-box;
    -webkit-box-sizing: border-box;

    user-select: none;
    -webkit-user-select: none;
    -ms-user-select: none;
    -moz-user-select: none;

    cursor: default;

    padding: 8px;

    margin: 8px;

    border: 1px solid rgba(0, 0, 0, 0.6) ;

    transition: background-color 0.3s, color 0.3s, border 0.3s;
}

.block:hover{

    color: white;
    background-color: darkcyan;
    border: 1px solid rgba(0, 0, 0, 0);

}