.header
	{
		width: 100%;
		height: 50px; 
		text-align: center;
		/* background-color: #468C00;
		color: #FFF; */
		position: fixed;
		z-index: 1;
		top: 0;
		left: 0;
	}
	
	.header .aa
	{
		height: 100%;
		overflow: hidden;
	}

	.header nav
	{
		height: 100%;
		display: table;
	}

	@media screen and ( max-width: 30em ) /* 480 */
	{
		.header span
		{
			display: inline;
		}
		.header b
		{
			display: none;
		}
	}