.fz-board {
  display: grid; gap: 1px; width: min(94vw, 380px); aspect-ratio: 1; margin: 0 auto;
  background: var(--ink); border: 2px solid var(--ink); border-radius: 8px; overflow: hidden;
}
.fz-cell {
  position: relative; background: var(--surface); display: grid; place-items: center;
  font-weight: 800; font-size: clamp(16px, 5.5vw, 26px); cursor: pointer; color: var(--ink);
  user-select: none;
}
.fz-cell.given { background: var(--surface-2); color: var(--grape); }
.fz-cell.sel { outline: 3px solid var(--grape); outline-offset: -3px; z-index: 3; }
.fz-cell .val { line-height: 1; }
.fz-cell .con {
  position: absolute; font-size: 13px; font-weight: 900; color: var(--coral); line-height: 1;
}
.fz-cell .con.r { right: -1px; top: 50%; transform: translate(50%, -50%); }
.fz-cell .con.b { bottom: -1px; left: 50%; transform: translate(-50%, 50%); }
#pad { display: flex; gap: 8px; flex-wrap: wrap; justify-content: center; }
#pad .num {
  width: 44px; height: 44px; border-radius: 12px; border: 2px solid var(--line);
  background: var(--surface); font-weight: 800; font-size: 18px; cursor: pointer;
}
#pad .num:active { transform: scale(.94); }