body {
            display: flex;
            justify-content: center;
            align-items: center;
            height: 100vh;
            background: #f3f4f6;
            font-family: Arial, sans-serif;
            background-color: #0f8860;
        }

        .calculator {
            background: #1f2937;
            padding: 20px;
            border-radius: 15px;
            box-shadow: 0px 4px 15px rgba(0, 0, 0, 0.3);
        }

        #display {
            width: 100%;
            height: 60px;
            font-size: 24px;
            text-align: right;
            padding: 10px;
            border: none;
            border-radius: 10px;
            margin-bottom: 15px;
            background: #111827;
            border: 1px solid #374151;
            color: white;
            outline: none;
            box-sizing: border-box;
        }
        .operators{
            background: #f59e0b;
            color: white;
            /* grid-column: span 2; */
        }
        .delete{
            background-color: red;
            color: white;
        }

        .buttons {
            display: grid;
            grid-template-columns: repeat(4, 70px);
            gap: 10px;
        }

        button {
            height: 60px;
            font-size: 20px;
            border: none;
            border-radius: 10px;
            cursor: pointer;
            transition: 0.2s;
        }

        button:hover {
            opacity: 0.8;
        }

        .number {
            background: #374151;
            color: white;
            /* grid-column: span 2; */
        }

        .operator {
            background: #f59e0b;
            color: white;
        }

        .clear {
            background: #ef4444;
            color: white;
            /* grid-column: span 2; */
        }

        .equal {
            background: #10b981;
            color: white;
            grid-column: span 2;
        }