body {
    display: flex;
    flex-direction: column;

    font-family: sans-serif;

    width: 70%;
    margin-left: auto;
    margin-right: auto;
    margin-top: 2em;
    margin-bottom: 2em;

    background-color: #222;
    color: #ddd;
}

.flex-column {
    display: flex;
    flex-direction: column;
    align-items: center;
}

.flex-row {
    display: flex;
    flex-direction: row;
    justify-content: space-between;
}

.width-70 {
    width: 70%;
}

.width-100 {
    width: 100%;
}

.center-horizontal {
    margin-left: auto;
    margin-right: auto;
}

textarea {
    height: 40em;
}

label {
    padding-right: 1em;
    font-weight: bold;
}

div {
    margin-top: 1em;
    margin-bottom: 1em;
}

img {
    max-width: 100%;
    margin-top: 1em;
    margin-bottom: 1em;
    box-shadow: 4px 3px 3px black;
}

canvas {
    margin-top: 1em;
    margin-bottom: 1em;
    box-shadow: 4px 3px 3px black;
}

p {
    text-align: center;
}