.w1200{
    width: 1200px;
}

.mr-auto{
    margin: 0 auto;
}
.mr-t-30{
    margin-top: 30px;
}
.mr-t-50{
    margin-top: 50px;
}
.fixed{
	position: fixed;
	top: 0;
	z-index: 100;
}