subject_css.css

body{
	margin: 0px;
	font-family: 'Roboto', sans-serif;
	background-color: rgb(66, 176, 244);
}
.main{
	background-color: rgba(255, 255, 255,.5);
	height: 700px;
	width: 700px;
	position: absolute;
	top: 50%;
	left: 50%;
	transform: translateX(-50%) translateY(-50%);
}
.content{
	position: absolute;
	height: 100%;
	width: 100%;
	text-align: center;
}
.play{
	border: 0px;
	background-color: rgba(0,0,0,.25);
	font-weight: bold;
	color: rgb(255,255,255);
	font-size: 44px;
	margin: 2.5% 2.5%;
	cursor: pointer;
}
#a{
	position: absolute;
	top: 0px;
	left: 0px;
	width: 45%;
	height: 45%;
	align-self: left;
}
#b{
	position: absolute;
	width: 45%;
	top: 0px;
	left: 50%;
	height: 45%;
	align-self: left;
}
#c{
	position: absolute;
	width: 45%;
	top: 50%;
	left: 0px;
	height: 45%;
	align-self: left;
}
#d{
	position: absolute;
	width: 45%;
	top: 50%;
	left: 50%;
	height: 45%;
	align-self: left;
}