html - li width not fixing with parent ul tag

Question

I've checked some web pages I've developed. There are some css problems for li width.

Here is the code for the navigation menu:

ul.tabs {
  padding: 0px;
  list-style: none;
  background: transparent;
  border-bottom: 3px solid #ff6600;
  -moz-border-radius: 0px;
  -webkit-border-radius: 0px;
  border-radius: 0px;
  text-align: center;
  position: relative;
  width: 100%;
}
ul.tabs li {
  background-color: #ff6600;
  border-top-left-radius: 5px;
  border-top-right-radius: 5px;
  border: none;
  color: #f5ede3;
  display: inline-block;
  padding: 5px 15px;
  cursor: pointer;
  margin-left: 0px;
  width: 16%;
  text-align: center;
}
ul.tabs li.current {
  background: #f5ede3;
  color: #ff6600;
}

<ul class="tabs">
  <li data-tab="tabs-1" class="current">Amenities</li>
  <li data-tab="tabs-5">Attractions</li>
  <li data-tab="tabs-2">Rates</li>
  <li data-tab="tabs-6">Calendar</li>
  <li data-tab="tabs-4">Reviews</li>
  <li data-tab="tabs-3">Inquire</li>
</ul>

But I get the following result:

The width of the li tag is 16%. And the number of li is 6. Why is the total width of li tags larger than the ul width?

Answer 1

全局设置box-sizing: border-box为快速修复- 请参见下面的演示：

*{
  box-sizing: border-box;
}
ul.tabs {
  padding: 0px;
  list-style: none;
  background: transparent;
  border-bottom: 3px solid #ff6600;
  -moz-border-radius: 0px;
  -webkit-border-radius: 0px;
  border-radius: 0px;
  text-align: center;
  position: relative;
  width: 100%;
}
ul.tabs li {
  background-color: #ff6600;
  border-top-left-radius: 5px;
  border-top-right-radius: 5px;
  border: none;
  color: #f5ede3;
  display: inline-block;
  padding: 5px 15px;
  cursor: pointer;
  margin-left: 0px;
  width: 16%;
  text-align: center;
}
ul.tabs li.current {
  background: #f5ede3;
  color: #ff6600;
}

<ul class="tabs">
  <li data-tab="tabs-1" class="current">Amenities</li>
  <li data-tab="tabs-5">Attractions</li>
  <li data-tab="tabs-2">Rates</li>
  <li data-tab="tabs-6">Calendar</li>
  <li data-tab="tabs-4">Reviews</li>
  <li data-tab="tabs-3">Inquire</li>
</ul>

Answer 2

这应该可以工作：

ul.tabs li{
        background-color: #ff6600;
        border-top-left-radius:5px;
        border-top-right-radius:5px;
        border:none;
        color: #f5ede3;
        display: inline-block;
        padding: 5px 15px;
        cursor: pointer;
        margin-left:0px;
        width:16%;
        text-align:center;
        box-sizing: border-box;// Try adding this line (:
    }