HTMLify

body {
    background: #151515;
    height: 100vh;
    display: grid;
    place-items: center;
}

.input-wrapper label {
    position: relative;
    display: block;
    margin: 40px 0;
    color: #fff;
    font-size: 1.5em;
    cursor: pointer;
}

.input-wrapper input[type="checkbox"] {
    -webkit-appearance: none;
}

.input-wrapper i {
    position: absolute;
    display: inline-block;
    width: 25px;
    height: 25px;
    border: 2px solid #fff;
}

.input-wrapper input[type="checkbox"]:checked~i {
    height: 15px;
    width: 25px;
    border-top: none;
    border-right: none;
    transform: rotate(-45deg);
}

.input-wrapper span {
    position: relative;
    left: 40px;
    transition: 0.5s;
}

.input-wrapper span:before {
    content: "";
    position: absolute;
    top: 50%;
    left: 0;
    width: 100%;
    height: 1px;
    background: #fff;
    transform: translateY(-50%) scaleX(0);
    transform-origin: left;
    transition: transform 0.5s;
}

.input-wrapper input[type="checkbox"]:checked~span:before {
    transform: translateY(-50%) scaleX(1);
    transform-origin: right;
    transition: transform 0.5s;
}

.input-wrapper input[type="checkbox"]:checked~span {
    color: #fff;
}