table.sudoku {
    border-collapse: collapse;
    width: auto;
}
table.sudoku td.topleft {
    border-top: solid 1px black;
    border-left: solid 1px black;
    padding-top: 3px;
    padding-left: 5px;
}
table.sudoku td.top {
    border-top: solid 1px black;
    padding-top: 3px;
}
table.sudoku td.topright {
    border-top: solid 1px black;
    border-right: solid 1px black;
    padding-top: 3px;
    padding-right: 5px;
}
table.sudoku td.left {
    border-left: solid 1px black;
    padding-left: 5px;
}
table.sudoku td.center {
}
table.sudoku td.right {
    border-right: solid 1px black;
    padding-right: 5px;
}
table.sudoku td.bottomleft {
    border-bottom: solid 1px black;
    border-left: solid 1px black;
    padding-bottom: 3px;
    padding-left: 5px;
}
table.sudoku td.bottom {
    border-bottom: solid 1px black;
    padding-bottom: 3px;
}
table.sudoku td.bottomright {
    border-bottom: solid 1px black;
    border-right: solid 1px black;
    padding-bottom: 3px;
    padding-right: 5px;
}
table.sudoku div {
    width: 35px;
    margin-top: 2px;
    margin-bottom: 2px;
    margin-left: 1px;
    margin-right: 1px;
    border: solid 1px #aaaaaa;
    font-size: smaller;
    text-align: center;
}
table.sudoku div.complete {
    background: rgb(230, 230, 230);
}
table.sudoku div.correct {
    background: rgb(150, 255, 150);
}
table.sudoku div.incorrect {
    background: rgb(255, 150, 150);
}