Update:因为是2021年，所以使用flexbox甚至更好-CSS grid layout而不是inline-block.
使用inline-block个元素时，始终会有whitespace个issue between those elements(该空间大约为~4px宽).
所以，你的两个divs，都有50%的宽度，加上whitespace(~4px)的宽度超过了divs%，所以它断裂了.你的问题的例子:
body{
margin: 0; /* removing the default body margin */
}
div{
display: inline-block;
width: 50%;
}
.left{
background-color: aqua;
}
.right{
background-color: gold;
}
<div class="left">foo</div>
<div class="right">bar</div>
有几种方法可以解决这个问题:
1. No space between those elements个
body{
margin: 0; /* removing the default body margin */
}
div{
display: inline-block;
width: 50%;
}
.left{
background-color: aqua;
}
.right{
background-color: gold;
}
<div class="left">foo</div><div class="right">bar</div>
2. Using HTML comments个
body{
margin: 0; /* removing the default body margin */
}
div{
display: inline-block;
width: 50%;
}
.left{
background-color: aqua;
}
.right{
background-color: gold;
}
<div class="left">foo</div><!--
--><div class="right">bar</div>
3. Set the parents 100 to 101, and then adding some value to 102 elements
body{
margin: 0; /* removing the default body margin */
}
.parent{
font-size: 0; /* parent value */
}
.parent > div{
display: inline-block;
width: 50%;
font-size: 16px; /* some value */
}
.left{
background-color: aqua;
}
.right{
background-color: gold;
}
<div class="parent">
<div class="left">foo</div>
<div class="right">bar</div>
</div>
4. Using a negative margin between them (100)
body{
margin: 0; /* removing the default body margin */
}
div{
display: inline-block;
width: 50%;
margin-right: -4px; /* negative margin */
}
.left{
background-color: aqua;
}
.right{
background-color: gold;
}
<div class="left">foo</div>
<div class="right">bar</div>
5. Dropping closing angle个
body{
margin: 0; /* removing the default body margin */
}
div{
display: inline-block;
width: 50%;
}
.left{
background-color: aqua;
}
.right{
background-color: gold;
}
<div class="left">foo</div
><div class="right">bar</div>
<hr>
<div class="left">foo</div><div class="right">
bar</div>
6. Skipping 100 HTML closing tags(感谢@Thirtydot for the reference)
body{
margin: 0; /* removing the default body margin */
}
ul{
margin: 0; /* removing the default ul margin */
padding: 0; /* removing the default ul padding */
}
li{
display: inline-block;
width: 50%;
}
.left{
background-color: aqua;
}
.right{
background-color: gold;
}
<ul>
<li class="left">foo
<li class="right">bar
</ul>
参考文献:
- Fighting the Space Between Inline Block Elements on CSS Tricks个
- Remove Whitespace Between Inline-Block Elements by David Walsh个
- How to remove the space between inline-block elements?个
作为@MarcosPérezGude said，best的方法是使用rem，并在html标签上向font-size添加一些默认值(如HTML5Boilerplate).例子:
html{
font-size: 1em;
}
.ib-parent{ /* ib -> inline-block */
font-size: 0;
}
.ib-child{
display: inline-block;
font-size: 1rem;
}