:root { color-scheme: light dark; --paper: #ffffff; }
:root[data-mode="light"] { color-scheme: light; }
:root[data-mode="dark"] { color-scheme: dark; --paper: #15171c; }
@media (prefers-color-scheme: dark) { :root:not([data-mode="light"]) { --paper: #15171c; } }
html, body.app-page { height: 100%; margin: 0; overflow: hidden; background: var(--paper); }
.page-app, .page-app iframe { position: fixed; inset: 0; width: 100%; height: 100%; border: 0; display: block; }