input[type="checkbox"] {
    margin: 0;
    -webkit-appearance: none;
    position: relative;
    width: 16px;
    height: 16px;
    cursor: pointer;
    outline: none !important;
    border: 1px solid #000000;
    border-radius: 2px;
    background: #ffffff;
}
input[type="checkbox"]::before {
    content: "\2713";
    position: absolute;
    top: 50%;
    left: 50%;
    overflow: hidden;
    transform: scale(0) translate(-50%, -50%);
    line-height: 1;
}
input[type="checkbox"]:checked {
    background-color: #ffffff;
    border-color: #000000;
    color: #000000;
}
input[type="checkbox"]:checked::before {
    border-radius: 2px;
    transform: scale(1) translate(-50%, -50%)
}