.custom-black-radio {
    appearance: none;
    width: 20px;
    height: 20px;
    min-width: 20px;
    min-height: 20px;
    border: 2px solid #ccc;
    border-radius: 4px; 
    background: #fff;
    cursor: pointer;
    position: relative;
}

.custom-black-radio + label {
    cursor: pointer;
}

.custom-black-radio:checked {
    background: #000;
    border-color: #000;
}

.custom-black-radio:checked::after {
    content: '';
    position: absolute;
    left: 4px;
    top: 0px;
    width: 8px;
    height: 14px;
    border-right: 3px solid white;
    border-bottom: 3px solid white;
    transform: rotate(45deg);
}