/* Read the back, and the arithmetic. */
.about { padding: 0 var(--gutter) var(--section-gap); }
.about__grid { max-width: 1296px; margin-inline: auto; display: grid; }
.about__body { display: grid; gap: var(--s4); max-width: 62ch; padding-bottom: var(--s5); }
.about__hand { color: var(--terra-600); padding-left: var(--s5); }
.def {
  position: relative; z-index: 1; width: 84%; margin: -24px auto 0 0; padding: var(--s5); border-radius: 2px;
  background: linear-gradient(rgba(253, 241, 199, 0.94), rgba(253, 241, 199, 0.94)), url("../img/card-stock.webp") var(--sun-100);
  box-shadow: var(--card-shadow); transform: rotate(var(--tilt)); font-size: 1.125rem; line-height: 1.45;
}
@media (min-width: 900px) {
  .about__grid { grid-template-columns: repeat(12, minmax(0, 1fr)); column-gap: 24px; align-items: center; }
  .about__body { grid-column: 1 / 8; padding-bottom: 0; gap: var(--s5); }
  .def { grid-column: 9 / 13; width: 100%; margin: 0; font-size: 1.25rem; }
}

.arith { background: var(--sun-500); padding: var(--section-gap) var(--gutter); }
.arith__grid { max-width: 1296px; margin-inline: auto; display: grid; gap: var(--s6); }
.arith__text { display: grid; gap: var(--s4); max-width: 46ch; }
.arith .label { color: var(--sea-900); }
.sum {
  display: grid; gap: var(--s3); width: 92%; margin-left: auto; padding: var(--s5); border-radius: 2px;
  background: var(--paper); box-shadow: var(--card-shadow); transform: rotate(var(--tilt));
}
.tag { justify-self: start; padding: var(--s1) var(--s3); background: var(--sun-100); border-left: 4px solid var(--sun-500); font-size: var(--fs-label); font-weight: 500; text-transform: uppercase; letter-spacing: 0.12em; }
.sum__row { font-size: 1.0625rem; font-weight: 500; line-height: 1.15; }
.sum__row b { display: block; font-size: var(--fs-sum); font-weight: 800; }
.sum__row--big b { font-size: clamp(1.6rem, 1.2rem + 1.8vw, 2.6rem); }
.margin { display: flex; align-items: flex-start; gap: var(--s2); color: var(--sea-700); font-size: var(--fs-note); font-style: italic; line-height: 1.35; }
.margin .icon { margin-top: 0.3rem; }
.margin .hand { font-style: normal; font-size: 1.375rem; }
.margin--terra { color: var(--terra-600); }
.sum__row--big { padding-top: var(--s2); border-top: 1px dashed var(--terra-400); }
.arith__after { max-width: 46ch; }
@media (min-width: 900px) {
  .arith__grid { grid-template-columns: repeat(12, minmax(0, 1fr)); column-gap: 24px; align-items: start; }
  .arith__text { grid-column: 1 / 6; grid-row: 1 / 3; position: sticky; top: calc(var(--header-h) + var(--s7)); }
  .sum { grid-column: 7 / 13; width: 100%; padding: var(--s6); }
  .arith__after { grid-column: 7 / 12; }
}