.custom-dropdown {
    width: 220px; /* or auto if you want shrink-to-fit */
    padding: 10px 15px;
    font-size: 16px;
    text-transform: uppercase;
    color: white;
    border: 1px solid white;
    border-radius: 0; /* square corners */
    background-color: black;
    cursor: pointer;

    appearance: none;
    -webkit-appearance: none;
    -moz-appearance: none;

    background-image: url("data:image/svg+xml,%3Csvg%20viewBox%3D%220%200%2010%205%22%20xmlns%3D%22http%3A//www.w3.org/2000/svg%22%3E%3Cpath%20d%3D%22M0%200l5%205%205-5z%22%20fill%3D%22white%22/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 10px center;
    background-size: 10px 5px;
}

.custom-dropdown:focus {
    border-color: white;
    outline: none;
}