Module:Navigation header/styles.css

.navigation-header {
	margin: 1em 0;
	box-sizing: border-box;
	clear: both;
	background: #fff;
}
ul {
	display: flex;
	flex-direction: column;
	flex-wrap: wrap;
	text-align: center; /* noflex */
}
#leadtab a {
	color: #fff;
}
#emergencytab {
	border-top: 0.5em solid red;
}
li {
	flex:1 1 0;
	width: 100%;
	margin: 0;
	box-sizing: border-box;
	background-color: inherit;
	padding: 1em;
	font-weight: bold;
	border-top: 0.2em solid #666;
	text-transform: uppercase;
}
li.selected {
	background-color: #f8f9fa;
	border-left: 0.5em solid #666;
}
li a {
	color:#36c;
}
.navigation-header-content {
	font-size: 1em;
	background-color: #666;
	border-bottom: 2px solid #666;
	padding: 1em;
}
.navigation-header-icon {
	display:inline-block;
	margin:0 0.5em 0 0;
	vertical-align:text-bottom;
}
.navigation-header-break {
	clear:both;
}

@media (min-width:550px) {
	ul {
		flex-direction: row;
		padding: 0;
		margin-top: 0 !important; /* cancels out the sibling styling */
	}
	ul > li {
		display: inline-block; /* noflex */
		vertical-align:bottom; /* noflex */
		white-space: nowrap;
		width: auto;
		margin: .5em .5em 0 0;
		border-top: .5em solid #666;
		font-size: 1em;
	}
	li.selected {
		border-left: 0;
	}
}
@media (min-width:1000px) {
	ul > li {
		flex: 0 1 0;
	}
}