body {
    margin: 0;
    font-family: sans-serif;
    line-height: 1.5em;
}

*, *::before, *::after {
    box-sizing: border-box;
}

body > section, body > header, body > footer {
    max-width: 40rem;
    margin-left: auto;
    margin-right: auto;
}

header > h1 {
    margin: 0;
    padding: 0;
}

h1 img {
    margin-left: 2.5rem;
}

body > section {
    margin-bottom: 3rem;
}

section > * {
    padding-left: 5rem;
    padding-right: 5rem;
}

section > ul {
    padding-left: 7rem;
}

h2 {
    font-size: 1.4em;
    font-weight: normal;
    padding-left: 2rem;
}

h3 {
    font-size: inherit;
    font-weight: bold;
    padding-left: 5rem;
}

input[type=number]{
    max-width: 8ch;
}

.viewer img.avatar {
    height: 1.5em;
    width: 1.5em;
    background-color: #ccc;
    border-radius:100%;
    transform:translateY(25%);
}

.banner {
    border-left-width: .7rem;
    border-left-style: solid;
    padding-top: .6rem;
    padding-bottom: .6rem;
    margin-bottom: 1rem;
}

body > section > .banner {
    padding-left: 4.3rem;
}

.banner.enabled {
    border-left-color: transparent;
    background: #bbfbff;
}

.banner.disabled {
    border-left-color: transparent;
    background: #eee;
}

.banner.success {
    background: #dec;
    border-left-color: #4a2;
}

.banner.error {
    border-color: #a24;
    background: #ecd;
}

.banner.warning {
    border-color: #dc4;
    background: #eec;
}

form {
    margin: 1em auto;
}

.banner form {
    display: inline;
}

label {
    display: inline-block;
}

footer {
    font-size: 0.9rem;
    margin-top: 5rem;
    margin-bottom: 3rem;
    display: flex;
    flex-direction: row;
    justify-content: center;
}

footer p {
    margin: 0 0.7rem;
}

footer a {
    color: inherit;
}