body {
    font: 16px/1.5 Candara, Calibri, Segoe, Segoe UI, Optima, Arial, sans-serif;
    margin: 0;
    display: flex;
    flex-direction: column;
    place-items: center;
}

header {
    margin: 2em;
}

table {
    border-top: 1px solid #aaa;
    margin: 2em;
    border-collapse: collapse;
}
input{line-height: 2}
button{line-height: 2;cursor: pointer;min-width: 72px;}
table>tr {
    text-align: center;
    border-bottom: 1px solid #aaa;
    border-right: 1px solid #aaa;
}

table>tr>td:nth-last-child(-0n+3) {
    width: 100px;
    background: #f00;
}

table>tr>td:nth-last-child(-0n+2),
table>tr>td:last-of-type {
    width: 48px;
    background: #f0f;
}

table>tr>td {
    white-space:nowrap;
    line-height: 2;
    border-left: 1px solid #aaa;
    overflow: hidden;
    text-overflow: ellipsis;
    cursor: pointer;
    padding: 0 2px;
    user-select: none;
    box-sizing: border-box;
    min-width: 3ch;
}

table>tr>td:first-of-type {
    width: 100px;
    cursor: default;
}

.selected {
    background: #eee;
    box-shadow: 0 0 0 1px #000 inset;
}