/*
 * pageBackground.css
 * The page background shared by the sign-in pages and every members page:
 * the dark brown "leather" fade, lightest at the top and darkening towards
 * the bottom (owner's choice, 5 October 2026). The privacy notice,
 * guidelines and licensing pages use the same fade (documentPage.css), so
 * the whole site matches. The fade itself is defined once, in
 * tomeTheme.css (--tome-desk-fade); change it there.
 *
 * It is drawn by the browser (no image file), so it costs nothing to
 * download. "background-attachment: fixed" keeps it still while the page
 * scrolls.
 *
 * To use on a page: add the class "site-background-page" to <body>.
 *
 * The background is DARK. Nothing but the logo sits directly on it: the
 * header, the sign-in box and every page's sheet have their own solid,
 * light colours (with dark text). The "Duality" logo on the sign-in pages
 * is light parchment: 10:1 or more against the fade (WCAG 2.2 AA).
 */

.site-background-page {
    min-height: 100vh;
    background-color: var(--tome-desk-colour);
    background-image: var(--tome-desk-fade);
    background-attachment: fixed;
    color: var(--tome-ink-colour);
}

/* Keyboard focus outline in red ink: everything that can be focused sits
   on a light panel, where it stands out clearly. */
.site-background-page :focus-visible {
    outline-color: var(--tome-red-ink-colour);
}

/* The "Duality" logo on the sign-in pages: light parchment on the dark fade. */
.site-background-page .site-title {
    color: var(--tome-on-leather-colour);
}