.operand{flex:1;min-width:0;padding:.5rem .6rem;border:1px solid #d0d5dd;border-radius:10px;font:inherit}.buttons{display:grid;grid-template-columns:repeat(4,1fr);gap:8px;margin-top:12px}.btn{padding:.6rem 0;border:1px solid #d0d5dd;border-radius:10px;background:#fff;color:#1d2939;font:inherit;font-size:1.15rem;cursor:pointer;box-shadow:0 1px 2px #10182814;transition:background-color .12s,border-color .12s,transform 60ms}.btn:hover{background:#f2f4f7;border-color:#98a2b3}.btn:active{transform:translateY(1px);box-shadow:none}.btn:focus-visible{outline:2px solid #4f46e5;outline-offset:2px}.btn[aria-pressed=true]{background:#eef2ff;border-color:#4f46e5;color:#4338ca;font-weight:600}.btn-equals{border-color:#4f46e5;background:#4f46e5;color:#fff;font-weight:600}.btn-equals:hover{border-color:#4338ca;background:#4338ca}