message: fix inventory screen grid
diff: display: grid;
  grid-template-columns:
  repeat(
  - var(--character-columns),
  + var(--num-characters),
  calc(
  /* Equipped item border */ #{2 * ($equipped-item-border + $equipped-item-padding)} + /* Equipped + unequipped items */
  ((var(--character-columns) + 1) * (var(--item-size) + var(--item-margin))) + /* Column padding */
  