QRcode/static/css/main.css

#container {
    margin: 0 auto;
    padding: 10px;
    width: 420px;
    text-align: center;
}

.mainPage #container{
    width: 80%;
    min-width: 800px;
}

#textInput{
    width: 305px;
    padding-left: 5px;
    margin-bottom: 10px;
    float: left;
}

.mainPage #textInput{
    width: 100%;
    text-align: center;
    margin-bottom: 20px;
}

#newTabBtn{
    float: right;
}

#qrcodeDiv{
    width: 100%;
    text-align: center;
}

#qrcodeDiv img{
    margin: 0 auto;
}