body {
	font-family: Verdana;
	max-width: 85%;
	margin: 0 auto; 
	padding: 20px 10px;
	font-size: 1.4em;
	background-image: url(images/test.jpg);
	background-repeat: no-repeat; 
	background-attachment:fixed;
}                

h1 {
	background-color: white;
	border-radius: 10px;
	color: #294860;
	text-align: center;
	padding: 10px;
	margin: 10px auto;
	background-image: url(images/white.jpg);
}

h2 {
	background-color: white;
	border-radius: 10px;
	padding: 10px;
	margin: 10px auto;
	border: 2px solid #000000;
	text-align: center;
	background-image: url(images/white.jpg);
}

h2 a {
	text-decoration: none;
}

p {
	margin: 10px 0;
}

.chapter {
	border-radius: 10px;
	color: white;
	display: -webkit-flex;
    display: flex;
    margin-bottom: 40px;
}

.concept {
	background-color: #E0E0E0;
	padding: 4px;
	margin: 5px;
	border-radius: 10px;
	color: black;
	width: 33.3%;
	border: 2px solid #000000;
	background-image: url(images/white.jpg)
}

.concept-title {
	font-size: 28px;
	margin: 8px;
	text-align: center;
	color: #294860;
}

.concept-text {
	font-weight: lighter;
	margin: 6px;
	font-size: 17px;
}

.infoblock {
	background-color: white;
	border-radius: 10px;
	padding: 20px;
	margin: 10px auto;
	border: 2px solid #000000;
	text-align: left;
	color: #294860;
	font-size: 20px;
	background-image: url(images/white.jpg);
}

.comments {
	border-radius: 10px;
	color: white;
	height: 250px;
	display: -webkit-flex;
    display: flex;
    margin-bottom: 40px;
}

.input {
	background-color: #E0E0E0;
	padding: 4px;
	margin: 5px;
	border-radius: 10px;
	color: black;
	width: 50%;
	border: 2px solid #000000;
	text-align: center;
	background-image: url(images/white.jpg)
}

.output {
	background-color: #E0E0E0;
	padding: 10px;
	margin: 5px;
	border-radius: 10px;
	color: black;
	width: 50%;
	border: 2px solid #000000;
	font-size: 17px;
	text-align: left;
	overflow: auto;
	background-image: url(images/white.jpg)
}

#tabs ul {
	list-style: none;
	padding:0;
	margin:0;
}

#tabs li {
	float: left;
	border: 2px solid #294860;
	border-width: 5px 5px 0 1px;
	margin: 0 0.3em 0 0.3em;
	background: white;
}

#tabs a {
	text-decoration: none;
	font-family: Verdana;
	display: block;
	background: white;
	padding: 0.24em 1em;
	color: #294860;
	width: 5em;
	text-align: center;
}

#tabs #selected a {
	position: relative;
	top: 2px;
	background-image: url(images/white.jpg);
	color: black;
	font-weight: bold;
	}

#tabs a:hover {
	background: #294860;
	color: white;
	}

#content {
	border: 2px solid #000000;
	border-radius: 10px;
	clear: both;
	background-image: url(images/white.jpg);
}