.column-arithmetic{color:#243d39;background:#fff;border:1px solid #d4dfdb;border-radius:18px;max-width:520px;margin:14px auto;padding:16px}.column-arithmetic table{border-collapse:separate;border-spacing:4px 0;table-layout:fixed;text-align:center;width:100%}.column-arithmetic th:first-child{width:24px}.column-arithmetic thead th{text-transform:capitalize;padding:9px 2px;font-size:clamp(11px,2vw,15px);font-weight:800}.column-arithmetic td,.column-arithmetic tbody th{font-variant-numeric:tabular-nums;height:60px;font-size:clamp(28px,6vw,44px);font-weight:800}.column-arithmetic .column-active{background:#e5f2e9}.column-arithmetic .column-carry td,.column-arithmetic .column-carry th{color:#256d52;height:32px;font-size:22px}.column-carry td span{border:1px solid #80b69f;border-radius:6px;place-items:center;min-width:24px;display:inline-grid}.column-exchanged{justify-content:center;align-items:center;gap:4px;display:flex}.column-exchanged del{color:#7d8b86;font-size:18px;font-weight:500}.column-exchanged strong{color:#256d52;font-size:.85em}.column-result td,.column-result th{border-top:3px solid #315850}.column-empty{color:#95a89f;font-size:.8em;font-weight:500}.column-exchange-key{background:#fff1d6;border-radius:10px;justify-content:center;align-items:center;gap:12px;padding:12px;font-size:16px;font-weight:800;display:flex}.column-controls{justify-content:space-between;gap:10px;display:flex}.column-controls button{color:#264f3b;min-height:48px;font:inherit;cursor:pointer;background:#eff6ef;border:1px solid #c5d6cd;border-radius:10px;padding:10px 12px;font-weight:800}.column-controls button:disabled{opacity:.5;cursor:default}.column-instruction{font-size:17px;line-height:1.55}.column-equation{text-align:center;font-size:20px;font-weight:800}.column-controls button:focus-visible{outline-offset:3px;outline:3px solid #34775a}@media (width<=420px){.column-arithmetic{padding:10px}.column-controls button{font-size:13px}.column-exchanged del{font-size:14px}.column-exchange-key{gap:8px;font-size:14px}}