CSS techniques for controlling element alignment

The parent element must be a block element, which is divided into the following types according to the child elements:

1. The child element is an inline element: such as: a, span

a. Horizontally centered: Set on the parent element: text-align:center;

b. Vertical centering: Set the line height on the inline child element to be the same as the parent element: line-height

.box1 {
			width: 200px;
			height: 200px;
			background-color: #FFFF0A;
			text-align: center;  /*可以使内部行内元素水平居中*/
		}
		.box1 a {
			line-height: 200px;  /*子元素设置行高与父元素高度相同*/
		}
<div class="box1">
     <a href="">PHP中文网</a>
</div>

2. Child element It is multi-line inline text

a. Horizontal centering: parent element setting text-align:center

b. Vertical centering: parent element setting: display:table-cell;vertical-align:middle

.box2 {
			width: 200px;
			height: 200px;
			background-color: #FC0107;
			text-align: center;  /*可以使内部多行行内元素水平居中*/
			/*以下二个声明可以使多行文本垂直居中*/
			display: table-cell;  /*设置显示方式为表格单元格*/
			vertical-align: middle; /*设置该单元格内的元素垂直居中*/
		}
<div class="box2">
<span>php中文网</span><br>
<span>www.php.cn</span>
</div>

3. The child element is a block element:

a. Horizontal centering: the child element sets the left and right automatically: margin: auto;

b. Vertical centering: within multiple lines The joint text processing method is the same: display:table-cell;vertical-align:middle

.box3 {
			width: 200px;
			height: 200px;
			background-color: #66CCFF;
			/*以下二个声明可以使块级子元素垂直居中*/
			display: table-cell;  /*设置显示方式为表格单元格*/
			vertical-align: middle; /*设置该单元格内的元素垂直居中*/			
		}
		.box3 .child {
			width: 100px;
			height: 100px;
			background-color: #F4FF0A;
			margin: auto;  /*水平居中*/
		}
<div class="box3">
<div class="child"></div>
</div>

4. The child element is a block element with variable width: the most common paging navigation

a. Horizontal centering :The child element is converted to an in-line element, and the parent element is added: text-align:center

b. Vertical centering: line height can be added to the paginated ul line-height=parent.height

c. Bottom center: more commonly used, consistent with the vertical processing method of multi-line inline text, vertical-align:bottom;

.box4 {
			width: 200px;
			height: 200px;
			background-color: #FD6FCF;
			text-align: center;  /*可以使行内元素水平居中*/
			/*以下二个声明可以使块级子元素垂直居中*/
			display: table-cell;  /*设置显示方式为表格单元格*/
			vertical-align:bottom; /*设置该单元格内的元素底边居中*/	
		}
		.box4 ul {
			margin: 0;
			padding: 0;
			/*line-height: 200px;*/
		}
		.box4 li {
			list-style: none;
			display: inline;
		}
<div class="box4">
<ul>
<li><a href="">1</a></li>
<li><a href="">2</a></li>
<li><a href="">3</a></li>
<li><a href="">4</a></li>
<li><a href="">5</a></li>
</ul>
</div>

The above is the detailed content of CSS techniques for controlling element alignment. For more information, please follow other related articles on the PHP Chinese website!