style.css

input{
    border: 1px solid gray;
    width: 20px;
    height: 20px;
    text-align: center;
    font-weight: bold;
    font-size: 20px;
}

.row{
    display: inline-block;
}

.hr{
    margin-top: 10px;
}

.spacer{
    margin-left: 10px;
}

.board {
    text-align: center;
    border: 1px solid black;
    width: 300px;
    padding: 10px 0;
    display: inline-block;
    background: darkgray;
    box-shadow: 0 0 20px 2px;
}
.button1{
    margin-top: 10px;
    background: cornflowerblue;
    width: 50%;
    height: 30px;
    font-weight: bold;
    border-radius: 5px;
}

.button2{
    margin-top: 10px;
    background: lightcoral;
    width: 50%;
    height: 30px;
    font-weight: bold;
    border-radius: 5px;
}

.button3{
    margin-top: 10px;
    background: lightgreen;
    width: 50%;
    height: 30px;
    font-weight: bold;
    border-radius: 5px;
}


.container{
    text-align: center;
}

html{
    background: dodgerblue;
}

.actions{
    width: 280px;
    display: inline-block;
    margin: 20px 0;
}

.actions p{
    padding: 0px;
    margin: 10px 10px;
    font-size: 12px;
}