body{background:#000;color:#fd0}.operand{flex:1;min-width:0;padding:.5rem .6rem;border:1px solid #806f00;border-radius:10px;background:#000;color:#fd0;font:inherit}.buttons{display:grid;grid-template-columns:repeat(4,1fr);gap:8px;margin-top:12px}.btn{padding:.6rem 0;border:1px solid #806f00;border-radius:10px;background:#000;color:#fd0;font:inherit;font-size:1.15rem;cursor:pointer;transition:background-color .12s,border-color .12s,transform 60ms}.btn:hover{background:#1a1600;border-color:#fd0}.btn:active{transform:translateY(1px)}.btn:focus-visible{outline:2px solid #ffdd00;outline-offset:2px}.btn[aria-pressed=true]{background:#332c00;border-color:#fd0;font-weight:600}.btn-equals{border-color:#fd0;background:#fd0;color:#000;font-weight:600}.btn-equals:hover{border-color:#ffe94d;background:#ffe94d}