table {
    border-collapse: collapse;
    width: 100%;
}

th {
    cursor: pointer;
    position: relative;
}

.arrow {
    display: inline-block;
    vertical-align: middle;
}

.arrow-generic {
    display: inline-block;
    vertical-align: middle;
}


.arrow::before {
    content: "";
}

.arrow-up::before {
    content: "▲";
}

.arrow-down::before {
    content: "▼";
}


.arrow-generic::before {
    content: "";
}

.arrow-generic-up::before {
    content: "▲";
}

.arrow-generic-down::before {
    content: "▼";
}

tr:nth-child(even) {
    background-color: #f2f2f2;
}