custom checkbox 2023

html

<label>
    <input type="checkbox">
    <i></i>
</label>

css

body {
    min-height: 100vh;
    display: grid;
    place-items: center;
    box-sizing: border-box;
    background-color: #fff;
}

label {
    position: relative;
    user-select: none;
}

label input {
    -webkit-appearance: none;
    appearance: none;
    position: relative;
    cursor: pointer;
}

label input::before {
    content: "";
    width: 30px;
    height: 30px;
    position: absolute;
    border: 2px solid #333;
}

i {
    position: relative;
    display: inline-block;
}

label i::before {
    content: "";
    position: absolute;
    width: 0;
    height: 2px;
    background-color: #333;
    top: 14px;
    transform: rotate(45deg);
    transition: all 0.1s;
    transform-origin: left;
}

label i::after {
    content: "";
    position: absolute;
    width: 0;
    height: 2px;
    background-color: #333;
    top: 21px;
    left: 6px;
    transform: rotate(-45deg);
    transition: all 0.1s;
    transform-origin: left;
    transition-delay: 0.1s;
}

label input:checked + i:before {
    width: 10px;
}

label input:checked + i:after {
    width: 20px;
}