stylesheet.css

body {
    font-family: "Ubuntu","Verdana","Times", Georgia, Serif;
    text-align: center;
    padding: 50px;
    line-height: 180%;
}

p {
    padding: 10px;
}

h2 {
    text-align: center;
}

.smallBtn {
    margin: 10px 0 10px 0;
    background-color: #2C3539;
    -moz-border-radius: 5px;
    -webkit-border-radius: 5px;
    border-radius:6px;
    color: #fff;
    font-size: 15px;
    text-decoration: none;
    cursor: pointer;
    border:none;
}

.smallBtn:hover {
    border: none;
    background:green;
    box-shadow: 0 0 1px #777;
}

.quiz > #main {
/* border:5px solid red; *//* debug*/
    margin: auto;
    width:75%;
    text-align: left;
    padding: 15px;
    background-color: #E5E4E2;
    border-radius:16px;
}

#header {
    padding: 0;
}

#content {
    margin:auto;
    height: 50%;
}

#footer{
    clear:both;
    margin:auto;
    position: fixed;
    left: 42%;
    bottom: -20px;
    height: 75px;
}

#percentage {
    text-align:center;
    font-size:50px;
}

#wrong {
    background-color: red;
    border-radius:10px;
}

#correct {
    background-color: green;
    border-radius:10px;
}

.btn {
	-moz-box-shadow:inset 0 0 10px 0 #caefab;
	-webkit-box-shadow:inset 0 0 10px 0 #caefab;
	box-shadow:inset 0 0 10px 0 #caefab;
	background:-webkit-gradient(linear, left top, left bottom, color-stop(0.05, #77d42a), color-stop(1, #5cb811));
	background:-moz-linear-gradient(top, #77d42a 5%, #5cb811 100%);
	background:-webkit-linear-gradient(top, #77d42a 5%, #5cb811 100%);
	background:-o-linear-gradient(top, #77d42a 5%, #5cb811 100%);
	background:-ms-linear-gradient(top, #77d42a 5%, #5cb811 100%);
	background:linear-gradient(to bottom, #77d42a 5%, #5cb811 100%);
	filter:progid:DXImageTransform.Microsoft.gradient(startColorstr='#77d42a', endColorstr='#5cb811',GradientType=0);
	background-color:#32CD32;
	-moz-border-radius:9px;
	-webkit-border-radius:9px;
	border-radius:9px;
	border:1px solid #268a16;
	display:inline-block;
	cursor:pointer;
	color:#306108;
	font-size:19px;
	font-weight:bold;
	padding:18px 76px;
    margin: 5px;
	text-decoration:none;
	text-shadow:0 1px 0 #aade7c;
}
.btn:hover {
	background:-webkit-gradient(linear, left top, left bottom, color-stop(0.05, #5cb811), color-stop(1, #77d42a));
	background:-moz-linear-gradient(top, #5cb811 5%, #77d42a 100%);
	background:-webkit-linear-gradient(top, #5cb811 5%, #77d42a 100%);
	background:-o-linear-gradient(top, #5cb811 5%, #77d42a 100%);
	background:-ms-linear-gradient(top, #5cb811 5%, #77d42a 100%);
	background:linear-gradient(to bottom, #5cb811 5%, #77d42a 100%);
	filter:progid:DXImageTransform.Microsoft.gradient(startColorstr='#5cb811', endColorstr='#77d42a',GradientType=0);
	background-color:#5cb811;
}
.btn:active {
	position:relative;
	top:1px;
}