:root {
    --bg: #222;
    --fg: #eee;
}

@media (prefers-color-scheme: light) {
    :root {
        --bg: #eee;
        --fg: #111;
    }
}

html,
body {
    height: 100svh;
    background: var(--bg);
    color: var(--fg);
    font-family: Helvetica, sans-serif;
    margin: 0;
}

* {
    box-sizing: border-box;
}

.wrapper {
    display: grid;
    grid-template-areas:
        "header header header"
        "nav    main    aside"
        "footer footer footer";
    grid-template-columns: min(100px, .25fr) 1fr min(100px, .25fr);
    grid-template-rows: auto 1fr auto;
    height: 100%;
    gap: 8px;
}

.app {
    height: 100%;
}

header {
    grid-area: header;
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 8px;
}

header h2 {
    font-family: 'Segoe Print', 'Lucida Sans', sans-serif;
    margin: 12px;
}

nav {
    grid-area: nav;
}

main {
    grid-area: main;
}

aside {
    grid-area: aside;
}

footer {
    grid-area: footer;
    padding: 16px;
    border-top: 1px solid gray;
}

button {
    cursor: pointer;
    background: none;
    border: none;
}