.maxw-70ch{max-width:70ch}

:root {
  --section-black: #000000;   /* full black */
  --section-black-text: #ffffff; /* text color for black sections */
}

.section-black {
  background: var(--section-black) !important;
  color: var(--section-black-text) !important;
}

.section-black a {
  color: #ff4444 !important; /* optional—visible link color */
}

.section-black .section-title {
  color: #ffffff !important;
}

:root {
  --section-light: #f5f5f5;   /* light grey */
  --section-dark:  #e2e2e2;   /* darker grey */
}

.section-light {
  background: var(--section-light);
}

.section-dark {
  background: var(--section-dark);
}

main section:nth-of-type(2n+1) {
  background: var(--section-light);
}

main section:nth-of-type(2n) {
  background: var(--section-dark);
}

.section {
  font-weight: 700;
}