:root {
    --header-height: 48px;
    --footer-height: 40px;
}

/* Make the page fill the viewport */
html, body {
    height: 100%;
    margin: 0;
}

/* Fixed header */
#header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--header-height);
    z-index: 1000;
}

/* Fixed footer */
#footer {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    height: var(--footer-height);
    z-index: 1000;
}

/* Content fills the space between header and footer */
#content {
    position: absolute;
    top: var(--header-height);
    bottom: var(--footer-height);
    left: 0;
    right: 0;
    overflow-y: auto;
    padding: 1rem;
}