/*
 * section, a section of a page: label, head, prose, optional figure. The vertical rhythm in whole
 * line boxes. Unforged house identity 3.1.0 Broadside, 2026-08-22. Owner: Andreas. Layer: 03 organisms.
 *
 * Composes the label atom (.u-label), the type atom (.u-type--head), the stack and the measure
 * (00_SHARED/base.css .u-stack, .u-measure) and, in the figure slot, the explainer-object molecule
 * or the figure molecule; a page links their sheets before this one. This sheet is layout: the
 * column, the air, the two columns of the figure variant.
 *
 *   .u-section           the section, paper, full width on a surface. Six line boxes of padding at
 *                        1280, three at 390 (space.section). Two sections in sequence share one
 *                        hairline in the ground's rule
 *   .u-section--figure   the body is two columns from 48rem: prose left, figure right
 *   .u-section__inner    the column: measure.document inside the two space.page margins
 *   .u-section__label    the label atom's place (u-label u-label--block u-section__label)
 *   .u-section__head     the head at the type atom's head step (Big Shoulders Display 800 uppercase
 *                        since 3.1.0, 26 to 36px), half a box
 *                        under the label (two rows are one box), prose measure
 *   .u-section__body     one line box under the head: the prose (u-measure u-stack), or the prose
 *                        beside a figure, two line boxes apart
 *   .u-section__figure   the figure slot: an explainer-object or a figure molecule. A chrome object
 *                        sits here against the type, on paper, never on a signal field
 */
.u-section {
  display: block;
  background-color: var(--u-color-ground-paper);
  padding-block: var(--u-space-section);
}
.u-section + .u-section {
  border-block-start: var(--u-line-hairline) solid var(--u-ground-rule);
}
.u-section__inner {
  box-sizing: content-box;
  max-width: var(--u-measure-document);
  margin-inline: auto;
  padding-inline: var(--u-space-page);
}
/* The body's prose measure, 538 / 570px (base.css section 7): 56ch at the head step resolved
   to 830 / 1149px, the whole column at 1280, over a 570px body (craft review 2026-08-22). */
.u-section__head { max-width: var(--u-measure-prose-body); }
.u-section__label + .u-section__head { margin-block-start: var(--u-space-row); }
.u-section__body {
  margin-block-start: var(--u-space-para);
  display: grid;
  gap: var(--u-space-block);
  align-items: start;
}
.u-section__figure { margin: 0; }
/* From 48rem the prose and the figure sit side by side in two equal columns; under it they stack,
   figure after prose. 48rem is the breakpoint the flush device uses (00_SHARED/README.md, Open 4). */
@media (min-width: 48rem) {
  .u-section--figure .u-section__body { grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); }
}