style.css

header {
    margin: 1em auto;
    text-align: center;
    display: flex;
    align-items: center;
    justify-content: center;
  }
  

  h1 {
    color: #333;
    font-family: tahoma;
    font-size: 3rem;
    font-weight: 900;
    line-height: 1.5;
    text-transform: uppercase;
    white-space: nowrap;
    overflow: hidden;
    position: relative;
    width: 550px;
  }
  
  
  body {
    background-color: #DBF9FC;
    }
    

.calculator {
    width: 400px;
    background-color: #a933df;
    padding: 50px 30px;
    position: absolute;
    transform: translate(-50%, -50%);
    top: 50%;
    left: 50%;
    border-radius: 8px;
    box-shadow: © 20px 50px rgb(40,113,85,04);

}


  
    .display {
    width: 100%;
    }
    .display input {
    width: 100%;
    padding: 15px 10px;
    text-align: right;
    border: none;
    background-color: transparent;
    color: #ffffff;
    font-size: 35px; 
    }
    
    .display input::placeholder {
        color: #eae9f1;
        
        }
        
        .buttons {
        display: grid;
        grid-template-columns: repeat(4, 1fr);
        grid-gap: 20px;
        margin-top: 40px;
        
        }
        
        .buttons input[type="button"] {
        font-size: 20px;
        padding: 17px;
        border: none;
        background-color: transparent;
        color: #ffffff;
        cursor: pointer;
        border-radius: 5px;
        
        }
        
        input[type="button" ]#equal {
        grid-row: span 2;
        background-color: #FA726B;
        
        }
        
        input[type="button"][value="0"] {
        grid-column: span 2;
        
        }