@layer layout {

body {
  display: flex;
  flex-direction: column;
  min-block-size: 100vh;
  min-block-size: 100dvh;
}

header, main, footer {
  inline-size: min(100% - var(--pad), var(--content));
  margin-inline: auto;
  border-inline: var(--border);
}

header, footer {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  padding: var(--pad-sm) var(--gutter);
}

footer {
  border-block-start: var(--border);
  text-align: center;
  color: var(--muted);
}

main {
  flex-grow: 1;
  display: flex;
  flex-direction: column;
  border-block-start: var(--border);
  background-color: white;
}

.flash {
  border-block-end: var(--border);
  padding: var(--pad-xs) var(--pad);
  font-weight: var(--bold);
  text-align: center;
}

section {
  padding: var(--gutter);
  border-block-end: var(--border);
}
section:last-child { border-block-end: none; }

.split {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  gap: var(--gutter);
}
.split.wide-start { grid-template-columns: minmax(0, 1.2fr) minmax(0, 0.8fr); }
.split.wide-end   { grid-template-columns: minmax(0, 0.8fr) minmax(0, 1.2fr); }

/* Split columns carry the padding so their backgrounds and borders reach the section edges. */
section.split { padding: 0; }
section.split > * { padding: var(--gutter); }
section.split > :first-child { padding-inline-end:   0; }
section.split > :last-child  { padding-inline-start: 0; }

@media (width <= 760px) { /* tablet */
  header, footer {
    flex-direction: column;
    align-items: center;
    gap: var(--pad-xs);
  }

  .split,
  .split.wide-start,
  .split.wide-end {
    grid-template-columns: minmax(0, 1fr);
    gap: 0;
  }

  section.split > :first-child { padding-inline-end:   var(--gutter); }
  section.split > :last-child  { padding-inline-start: var(--gutter); }
}

}