* {
    margin: 0;
    padding: 0;
    -moz-box-sizing: border-box; 
    -webkit-box-sizing: border-box; 
    box-sizing: border-box;
}

body {
    //font-family: 'Helvetica Neue','Helvetica', Arial, sans-serif;
}

.main-content {
    height: 800px;
    width: 1000px;
    margin: 0 auto;
}

.overlay-bg {
    display: none;
    position: absolute;
    top: 0;
    left: 0;
    height:100%;
    width: 100%;
    cursor: pointer;
    z-index: 1000; /* high z-index */
    background: #000; /* fallback */
    background: rgba(0,0,0,0.75);
}
.overlay-content {
    display: none;
    background: #fff;
    padding: 1%;
    width: 40%;
    position: absolute;
    top: 15%;
    left: 50%;
    margin: 0 0 0 -20%; /* add negative left margin for half the width to center the div */
    cursor: default;
    z-index: 10001;
    border-radius: 4px;
    box-shadow: 0 0 5px rgba(0,0,0,0.9);
}

/*
.close-btn {
    cursor: pointer;
    border: 1px solid #333;
    padding: 2% 5%;
    background: #a9e7f9;
    background: -moz-linear-gradient(top,  #a9e7f9 0%, #77d3ef 4%, #05abe0 100%);
    background: -webkit-gradient(linear, left top, left bottom, color-stop(0%,#a9e7f9), color-stop(4%,#77d3ef), color-stop(100%,#05abe0));
    background: -webkit-linear-gradient(top,  #a9e7f9 0%,#77d3ef 4%,#05abe0 100%);
    background: -o-linear-gradient(top,  #a9e7f9 0%,#77d3ef 4%,#05abe0 100%);
    background: -ms-linear-gradient(top,  #a9e7f9 0%,#77d3ef 4%,#05abe0 100%);
    background: linear-gradient(to bottom,  #a9e7f9 0%,#77d3ef 4%,#05abe0 100%);
    border-radius: 4px;
    box-shadow: 0 0 4px rgba(0,0,0,0.3);
}
.close-btn:hover {
    background: #05abe0;
}
*/

/* media query for most mobile devices */
@media only screen and (min-width: 0px) and (max-width: 480px){

    .overlay-content {
        width: 96%;
        margin: 0 2%;
        left: 0;
    }
}