Div in center krijgen.

@charset "utf-8";
/* CSS Document */


body {
background-color: #fff;
margin: 0px auto;
}


.top {
background-color: #ffffff;
width: 100%;
height: 200px;
}


.logo {
background-image: url("images/logo.png");
background-repeat: no-repeat;
width: 278px;
height: 57px;
margin-top: 4%;
margin-left: 26%;
}


.loginbox {
padding-top: 2px;
padding-left: 10px;
background-image: linear-gradient(bottom, rgb(3,55,74) 16%, rgb(8,88,117) 79%);
background-image: -o-linear-gradient(bottom, rgb(3,55,74) 16%, rgb(8,88,117) 79%);
background-image: -moz-linear-gradient(bottom, rgb(3,55,74) 16%, rgb(8,88,117) 79%);
background-image: -webkit-linear-gradient(bottom, rgb(3,55,74) 16%, rgb(8,88,117) 79%);
background-image: -ms-linear-gradient(bottom, rgb(3,55,74) 16%, rgb(8,88,117) 79%);


background-image: -webkit-gradient(
	linear,
	left bottom,
	left top,
	color-stop(0.16, rgb(3,55,74)),
	color-stop(0.79, rgb(8,88,117))
);
height: 80%;
width: 20%;
margin-left: 58.8%;
margin-top: -6.5%;
border-radius: 15px 15px 0 0;
}


.loginbox h2 {
font-size: 18px;
color: #fff;
font-weight: 100;
}


.menu {
background-color: #03374a;
width: 100%;
height: 18%;
margin-top: -0.8%;
}


.container {
margin: 0px auto 0px auto;
}


.subbalk {
position: absolute;
background-color: #000;
width: 40%;
height: 20%;
}