Text centered

Middle horizontal text: text-align: center;
single text vertical center: line-height: the height of the box

Line-height: start from where the end of a line of text, the next line of text to the end of the local end

Case:

（1）html

<H1> This is the text </ h1>

(2)css

h1{
height: 150px;
border: 1px solid #000;
text-align: center;
line-height: 150px;
}