Landmarks & section
body > header, main and footer are centered columns out of the box; sections space themselves vertically.
Landmarks
<body>
<header>…</header>
<main>…</main>
<footer>…</footer>
</body><body>
<header>…</header>
<main>…</main>
<footer>…</footer>
</body>Each direct landmark child of body gets the --v-block-spacing-vertical / -horizontal padding. The role and class aliases ([role="main"], .tag-main, …) count as landmarks too, and an .abstract wrapper between body and the landmark is looked through (an <include-content class="abstract"> around a header keeps it a landmark).
Section
section (and [role="section"] / .tag-section) is a block with --v-block-spacing-vertical below it. The spacing grows with the viewport: 1× --v-spacing below 576px up to 2.25× at 1536px, on landmarks, sections and cards alike.
Document
The root sets the font stack, size, weight, line height, overflow-wrap: break-word, box-sizing: border-box everywhere and a responsive root font size (100% → 131.25% at 1536px), so every rem scales with the viewport.