* { padding: 0; margin: 0; 
}
#heading {
    text-align: center;
    margin-top: 15px;
    margin-bottom: 15px;
    font-size: xx-large;
}
#heading{ margin: 0 auto}
#canvas { background: lightblue; display: block; margin: 0 auto; }
#c { background: lightgreen; display: block; margin: 0 auto; }
#timerel { background: greenyellow; display: block; margin: 0 auto; }
.modal {
    display: none; 
    position: fixed;
    z-index: 1;
    padding-top: 20%;
    left: 0;
    top: 0;
    width: 100%; 
    height: 100%; 
    overflow: auto; 
    background-color: royalblue; 
    background-color: rgba(0,0,0,0.4); 
}
.modal-content {
    position: relative;
    background-color: #fefefe;
    margin: auto;
    padding: 0;
    border: 1px solid #888;
    width: 30%;
    box-shadow: 0 4px 8px 0 rgba(0,0,0,0.2),0 6px 20px 0 rgba(0,0,0,0.19);
    -webkit-animation-name: animatetop;
    -webkit-animation-duration: 0.4s;
    animation-name: animatetop;
    animation-duration: 0.4s
}

@-webkit-keyframes animatetop {
    from {top:-300px; opacity:0}
    to {top:0; opacity:1}
}

        @keyframes animatetop {
            from {top:-300px; opacity:0}
            to {top:0; opacity:1}
        }
        .close {
            color: white;
            float: right;
            font-size: 28px;
            font-weight: bold;
        }

        .close:hover,
        .close:focus {
            color: #000;
            text-decoration: none;
            cursor: pointer;
        }

        .modal-header {
            padding: 2px 16px;
            background-color: lightgoldenrodyellow;
            color: royalblue;
            text-align: center;
            height : 50%;
        }

        .modal-body {padding: 2px 16px;}

        .modal-footer {
            padding: 2px 16px;
            background-color: orangered;
            color: white;
            text-align: center;
            height: 50%;
        }
        .a1{
            text-align: center;
            margin-bottom: 10px;
            color: mediumvioletred; 
            
        }
        span{
            background-color: yellow;
        }