.calculator { width: 300px; margin: 50px auto; background-color: #333; border-radius: 10px; overflow: hidden; } .calculator input { width: 100%; padding: 20px; font-size: 24px; border: none; background-color: #222; color: white; text-align: right; white-space: nowrap; overflow-x: auto; } .calculator .buttons { display: grid; grid-template-columns: repeat(4, 1fr); } .calculator button { padding: 20px; font-size: 20px; border: none; background-color: #444; color: white; cursor: pointer; transition: background-color 0.3s ease; } .calculator button:hover { background-color: #555; } .calculator button:active { background-color: #666; } .calculator .buttons button:nth-child(4n) { background-color: #f0a040; } .calculator .buttons button:nth-child(4n):hover { background-color: #f2b96e; }