*{
    box-sizing: border-box;
}
.popup{
    position: absolute;
    width: 500px;
    left: 50%;
    top: 35%;
    margin-left: -150px;
    min-height: 200px;
    display: none;
    background: #111;
    background-size: cover;
    color: white;
    font-family: sans-serif;
    padding: 30px;
}

.popup button{
    display: inline-block;
    float: right;
}

button{
    cursor: pointer;
    background: #000;
    color: white;
    padding: 10px;
    font-family: sans-serif;
    background-size:cover;
    border: none;
}
body{
    margin: 0;
    padding: 0;
}
img{
    max-width: 100%;
    height: auto;
    width: 100%;
}