try 使用最多包含5个项目、最少包含3个项目的Flexbox导航，但它没有在所有元素之间平均分配宽度.
Fiddle
我为这个建模的教程是http://www.sitepoint.com/responsive-fluid-width-variable-item-navigation-css/
萨斯
* {
font-size: 16px;
}
.tabs {
max-width: 1010px;
width: 100%;
height: 5rem;
border-bottom: solid 1px grey;
margin: 0 0 0 6.5rem;
display: table;
table-layout: fixed;
}
.tabs ul {
margin: 0;
display: flex;
flex-direction: row;
}
.tabs ul li {
flex-grow: 1;
list-style: none;
text-align: center;
font-size: 1.313rem;
background: blue;
color: white;
height: inherit;
left: auto;
vertical-align: top;
text-align: left;
padding: 20px 20px 20px 70px;
border-top-left-radius: 20px;
border: solid 1px blue;
cursor: pointer;
}
.tabs ul li.active {
background: white;
color: blue;
}
.tabs ul li:before {
content: "";
}<div class="tabs">
<ul>
<li class="active" data-tab="1">Pizza</li>
<li data-tab="2">Chicken Noodle Soup</li>
<li data-tab="3">Peanut Butter</li>
<li data-tab="4">Fish</li>
</ul>
</div>