body{margin: 0 auto;padding: 0;background-image: url(../img/physicsbg.png);background-repeat:no-repeat;background-size:cover;font-family: 'Open Sans', sans-serif;}
h1{line-height: 0.5;}
h3{line-height: 1}
#main {
    height: 500px;
    width: 1000px;
    margin: auto;
    /*margin-top: 55px;*/
    background-repeat: no-repeat;
}

.liter{
    padding: 5px;
}
.button,.button1{
    cursor: pointer;
    height: 32px;
    margin-bottom: 2px;
    background-color: #464646;
}
#ref{
    cursor: pointer;
}
.answer{
    height: 75px;
    width: 150px;
    margin-top: 250px;
    background-color: #464646;
    padding: 5px;
    color: #ffffff;
    margin-left:30px ;
    font-size: 25px;
}
.color-one{color: #ffc709;}
.color-two{color: #8f8d89;}
.question{
    margin-left: 15px;
    background-color: #f0f0f0;
    font-size: 22px;
    color: #080808;
}