h1{
	background: #B3B3B3;
	font-size: 150%;
}

header{
	background: #666666;
	text-align: center;
}

h1{
	color: #FFFFFF;
}

nav{
	font-variant: small-caps;
	font-size: 150%;
	font-family: Arial, "Time New Roman", serif;
}

h2{
	color: #666666;
	background: #00B7E8;
}

details{
	font-style: italic;
}

summary{
	font-style: normal;
}

footer{
	background: #666666;
}
Add lesson's excercise css file
Add lesson's excercise css file
