html, body {
    width: 100%;
    height: 100vh;
    margin: 0;
    padding: 0;
}

ul, li {
    list-style: none;
    padding: 0;
    margin: 0;
}

audio {
    display: none;
}

.flex-container {
    width: 100vw;
    height: 100vh;
    display: -webkit-flex;
    display: flex;  
    -webkit-flex-flow: column wrap;
    flex-flow: column wrap;
    text-align: center;
    align-items: stretch;
}

.flex-container-1 {
    background-size: cover;
    background-image: url('../images/page1.jpg'); 
    width: 100vw;
}
.flex-container-1 > * {
    -webkit-flex: 1 100%;
    flex: 1 100%;
}

.flex-container-3 {
    -webkit-flex-flow: row wrap;
    flex-flow: row wrap;
    background-size: cover;
    background: url('../images/page3.jpg');
    width: 100vw;
}
.record-button {
    -webkit-flex: 1 100%;
    flex: 1 100%;
    min-height: 25%;
}

.play-button {
    -webkit-flex: 1 20%;
    flex: 1 20%;
}
.active {background-color: red !important;}
 #demo {visibility: hidden; height: 100%;}
.play-button {border: solid black;}
.record-button {background: cyan;}