body,form{height:100%}

    .myModal {
    position: fixed;
    top: 0;
    right: 0;
    bottom: 0;
    left: 0;
    background: rgba(0, 0, 0, 0.8);
    opacity:0;
    -webkit-transition: opacity 400ms ease-in;
    -moz-transition: opacity 400ms ease-in;
    transition: opacity 400ms ease-in;
    pointer-events: none;
    z-index: 100;
    }
    .myModal:target {
        opacity:1;
        pointer-events: auto;
    }
    .myModal > div {
	    position: absolute;
	    top: 25%;
	    left: 25%;
	    width: 50%;
	    height: 50%;
	    padding: 16px;
	    border: 16px solid orange;
	    background-color: white;
	    overflow: auto;	
    }
    .txt
    {
        font-size : 14pt;   
    }