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

body {
 display: flex;
 align-items: center;
 background-color: #f9f9f9;
}
.background {
 position: absolute;
 display: block;
 top: 0;
 left: 0;
 z-index: -1;
 background: #000;
}
h3{
 font-size: 1em;
 font-weight: 100;
 margin-bottom: 0;
}
h2{
 font-size: 3em;
 font-weight: 100;
 color: #fff;
 margin: 0;
}
.container {
 display:flex;
 flex-flow: column wrap;
 text-align: center;
 align-items: center;
 justify-content:center;
 position:relative;
 width: 500px;
 font-size:25px;
 font-family: 'Roboto', sans-serif;
 border: 5px solid #fff;
 margin: 0 auto;
 border-radius:10%;
 padding: 40px;
background-image: url('img/background.jpg');
    box-shadow: 0 0 24px 0 rgba(0, 0, 0, 0.13), 0 1px 0 0 rgba(0, 0, 0, 0.02);
}


/*// Extra small devices (portrait phones, less than 576px)*/
@media (max-width: 575.98px) { 

.container {
    display: flex;
    flex-flow: column wrap;
    text-align: center;
    align-items: center;
    justify-content: center;
    position: relative;
    width: 900px;
    height: 500px;
    font-size: 35px;
    font-family: 'Roboto', sans-serif;
    border: 5px solid #fff;
    margin: 0 auto;
    border-radius: 10%;
    padding: 50px;
    background-image: url(img/background.jpg);
    box-shadow: 0 0 24px 0 rgb(0 0 0 / 13%), 0 1px 0 0 rgb(0 0 0 / 2%);
}

 }

/*// Small devices (landscape phones, 576px and up)*/
@media (min-width: 576px) and (max-width: 767.98px) { 
.container {
    display: flex;
    flex-flow: column wrap;
    text-align: center;
    align-items: center;
    justify-content: center;
    position: relative;
    width: 1100px;
    height: 600px;
    font-size: 35px;
    font-family: 'Roboto', sans-serif;
    border: 5px solid #fff;
    margin: 0 auto;
    border-radius: 10%;
    padding: 50px;
    background-image: url(img/background.jpg);
    box-shadow: 0 0 24px 0 rgb(0 0 0 / 13%), 0 1px 0 0 rgb(0 0 0 / 2%);
}

 }

/*// Medium devices (tablets, 768px and up)*/
@media (min-width: 768px) and (max-width: 991.98px) { 

.container {
    display: flex;
    flex-flow: column wrap;
    text-align: center;
    align-items: center;
    justify-content: center;
    position: relative;
    width: 650px;
    height: 600px;
    font-size: 35px;
    font-family: 'Roboto', sans-serif;
    border: 5px solid #fff;
    margin: 0 auto;
    border-radius: 10%;
    padding: 50px;
    background-image: url(img/background.jpg);
    box-shadow: 0 0 24px 0 rgb(0 0 0 / 13%), 0 1px 0 0 rgb(0 0 0 / 2%);
}

 }

/*// Large devices (desktops, 992px and up)*/
@media (min-width: 992px) and (max-width: 1199.98px) { 

.container {
    display: flex;
    flex-flow: column wrap;
    text-align: center;
    align-items: center;
    justify-content: center;
    position: relative;
    width: 800px;
    height: 600px;
    font-size: 35px;
    font-family: 'Roboto', sans-serif;
    border: 5px solid #fff;
    margin: 0 auto;
    border-radius: 10%;
    padding: 50px;
    background-image: url(img/background.jpg);
    box-shadow: 0 0 24px 0 rgb(0 0 0 / 13%), 0 1px 0 0 rgb(0 0 0 / 2%);
}

 }