@charset "utf-8";

td {
    border: 1px solid black;
}

table {
    border-collapse: collapse;
}

#group1 {
    width: 128px;
    background-color: red;
}

#group2 {
    width: 64px;
    background-color: green;
}

#group3 {
    width: 32px;
    background-color: blue;
}

#group4 {
    width: 16px;
    background-color: silver;
}