.calc {width:100%; max-width:420px; background:#fff; padding:20px; border-radius:20px; margin:auto;}
.display {width:100%;height:80px;background:#000;color:#0f0;font-size:32px;text-align:right;padding:20px;border-radius:10px;overflow:hidden;}
.urdu-display {width:100%;min-height:50px;background:#222;color:#ffd700;font-size:24px;text-align:right;padding:10px;margin-top:8px;border-radius:10px;}
.buttons {margin-top:20px;display:grid;grid-template-columns:repeat(4,1fr);gap:12px;}
button {padding:20px;font-size:22px;border:none;border-radius:14px;background:#e0e0e0;cursor:pointer;font-weight:bold;transition:.2s;}
button:active {transform:scale(.95);background:#d0d0d0;}
.op {background:#ff9800;color:#fff;}
.eq {background:#4caf50;color:#fff;grid-column:span 2;}
.clear {background:#f44336;color:#fff;grid-column:span 2;}