colouring-montreal/app/src/frontend/styles/layout.css

/**
 * Main Layout
 */

html, body, #root {
    height: 100%;
}

body {
    margin: 0;
}

#root {
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

main {
    position: relative;
    flex: 1;
    display: flex;
    flex-direction: column;
    overflow: auto;
}

@media(min-width: 768px) {
    main {
        flex-direction: row;
        justify-content: center;
    }
 }
/**
 * Text pages
 */
article section {
    overflow: hidden;
    margin: 2.25em 0 4em;
}
article .color-block {
    padding: 2em 0 4em;
    margin-top: 0;
    margin-bottom: 0;
}
.main-col {
    max-width: 48em;
    margin-left: auto;
    margin-right: auto;
    padding-left: 1em;
    padding-right: 1em;
}
hr {
    display: block;
    height: 1px;
    border: 0;
    background: #000;
    width: 100%;
    margin: 2em 0;
    padding: 0;
}