body {
    font-family: Arial, sans-serif;
    text-align: center;
}

.calculator {
    margin: 0 auto;
    padding: 20px;
    background-color: #f3f3f3;
    border-radius: 15px;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.2);
	  color:lightblue;
    
}

#display {
    width: 50%;
    height: 40px;
    margin-bottom: 10px;
    font-size: 30px;
	 
}

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

button {
    width: 100%;
    height: 40px;
    font-size: 18px;
    background-color: #2196F3;
    color: #fff;
    border: none;
    border-radius:15px;
    cursor: pointer;
}

button:hover {
    background-color: green;
}