html {
    height: 100%;
    width: 100%;
    padding: 0;
    font-family: Arial, Helvetica, sans-serif;
    background-color: white;
}

html, body {
    margin: 0;
}

body {
    margin: auto;
    box-sizing: border-box;
    padding: 1em;
    max-width: 100%;
    width: 30em;
}

img {
    margin: auto;
    max-width: 100%;
    box-sizing: border-box;
}

label {
    display: block;
}

button {
    padding: .3em;
    font-size: 1em;
    width: 100%;
    box-sizing: border-box;
    border: none;
    /* border-bottom: 1px solid grey; */
    background-color: #f1f1f1;
    transition: background-color .2s;
    cursor: pointer;
}

button:hover {
    background-color: #e1e1e1;
}