body {

    text-align: center;
    
    margin: 0;
    
    background: black;
    
    display: flex; align-items: center;
    
    justify-content: center;
    
    height: 100vh;
    
    }
    
    #calculator {
    max-width: 360px;
    background-color: #0d1b2a;
    border-radius: 10px;
    padding: 20px;
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.19), 0 6px 6px rgba(0, 0, 0, 0.23);
    }
    #display {
    background-color: #000;
    color: whitesmoke;
    width: 100%;
    height: 56px;
    font-size: 20px;
    text-align: right;
    margin-bottom: 10px;
    padding: 20px;
    border-radius: rgb(0, 0, 0);
    border: none;
    box-sizing: border-box;
    border: none;
    }
    button {
    height: 50px;
    width: calc(25% - 10px);
    font-size: 20px;
    margin: 10px 5px;
    border-radius: 5px;
    float: left;
    background-color: rgb(13, 27, 42);
    color: #e0e1dd;
    -webkit-box-shadow: 1px 1px 30px -5px rgba(0, 0, 0, 0.2);
    -moz-box-shadow: 1px 1px 30px -5px rgba(0, 0, 0, 0.2);
    box-shadow: 1px 1px 30px 5px rgba(0, 0, 0, 0.2);
     } 
    .operator {
    
    color: #219ebc;
    }
    button:hover {  
    cursor: pointer;
    }   
    #ac {
    color: #bf4d5d;
    }
    .equal {
    width: calc(50% 10px);
    }
    button:active {
    transform: scale(1.05);
    box-shadow: 0 2px 4px 1px rgba(0, 0, 0, 0.19),
    23 0 1.5px 1.5px rgba(0, 0, 0, 0.23);
    }