button {
    clip: rect(0, 0, 0, 0);
    position: absolute;
}

label {
    display: inline-block;
    line-height: 20px;
    padding: 10px;
}

.father {
    width: 200px;
    height: 200px;
    padding: 0px;
    border: 1px solid red;
}

.son {
    border: 1px solid blue;
    height: 100%;
    /* margin: 0px 20px; */
    width: 300px;
}