HTMLify

body {
    display: grid;
    place-items: center;
    height: 100vh;
    background: #151515;
    color: white;
    font-family: sans-serif;
    font-size: 1.2rem;
}

.wrapper {
    display: flex;
    align-items: center;
}

input[type=radio] {
    display: none;
}

label {
    position: relative;
    margin-right: 1em;
    padding-left: 2em;
    padding-right: 1em;
    line-height: 2;
    cursor: pointer;
}

label:before {
    box-sizing: border-box;
    content: " ";
    position: absolute;
    top: 0.3em;
    left: 0;
    display: block;
    width: 1.4em;
    height: 1.4em;
    border: 2px solid white;
    border-radius: 0.25em;
    z-index: -1;
}

input[type=radio]+label::before {
    border-radius: 1em;
}

/* Checked */
input[type=radio]:checked+label {
    padding-left: 1em;
    color: #151515;
}

input[type=radio]:checked+label:before {
    top: 0;
    width: 100%;
    height: 2em;
    background: white;
}

/* Transition */
label,
label::before {
    transition: 0.25s all ease;
}