body{
    background: #009999;
    }
    h1{
        text-align:center;
        color:navy;
        font-size: 3em;
    }
    .main-content{
        width: 80%;
        margin: auto;
    }
    
    label{
        font-size: 1.5em;
        color: navy;
    }
    input[type=text], input[type=number] {
        width: 100%;
        padding: 12px 20px;
        margin: 8px 0;
        box-sizing: border-box;
    }
    
    input[type=submit] {
        width: 100%;
        padding: 12px 20px;
        margin: 8px 0;
        box-sizing: border-box;
        font-size: 1em;
        background: green;
        color: #fff;
        border: none;
        border-radius:8px;
        cursor: pointer;
    }
    
    input[type=submit]:hover{
       background: navy;
    }
    #alert{
        color:green;
        font-size:2em;
    }