:root { .is-layout-flow, .is-layout-constrained { > * + * { margin-block-start: 0; } } .is-layout-flow, .is-layout-constrained { > * { margin-bottom: var(--content-spacing); &:last-child { margin-bottom: 0; } } h1, h2, h3, h4, h5, h6 { margin-top: var(--content-spacing); margin-bottom: calc(var(--has-content-spacing, 1) * (0.3em + 10px)); &:first-child { margin-top: 0; } } } }