.lau_logo {
    display: inline-block;
    float: left;
    width: 400px;
    height: 87px;
    background-image: none;
    background-repeat: no-repeat;
    background-position: 0 0;
    background-size: 210px 87px;
}

.main_nav {
    font-size: 1.4rem;
}


@media only screen and (max-width: 640px){
	.lau_logo {
		width: 280px;
	}
}

@media only screen and (min-width:981px){
	.lau_logo {
		width:400px;
	}
}
   

.top_nav_group {
    float: right;
    width: 60%;
}

@media only screen and (max-width: 980px){
	.top_nav_group {
		float: left;
		width: 100%;
	}
}


@media only screen and (min-width: 981px) and (max-width: 1088px){
	.main_nav > ul > li > a{
		padding:0.2em 0.2em;
	}
	.main_nav {
		font-size: 1.3rem;
	}
	.lau_logo {
		width:361px;
	}
}