.box {
    background: #666666;
    color: #ffffff;
    width: 250px;
    padding: 10px;
    margin: 1em auto;
}

p {
    margin: 1.5em 0;
    padding: 0;
}

input[type="checkbox"] {
    visibility: hidden;
}

label {
    cursor: pointer;
}

input[type="checkbox"] + label:before {
    border: 1px solid #333;
    content: "\00a0";
    display: inline-block;
    font: 16px/1em sans-serif;
    height: 16px;
    margin: 0 .25em 0 0;
    padding: 0;
    vertical-align: top;
    width: 16px;
}

input[type="checkbox"]:checked + label:before {
    background: #fff;
    color: #333;
    content: "\2713";
    text-align: center;
}

input[type="checkbox"]:checked + label:after {
    font-weight: bold;
}

input[type="checkbox"]:focus + label::before {
    outline: rgb(59, 153, 252) auto 5px;
}

<div class="conte