In line elements are transformed into block level elements, and display transformation and implicit transformation

The upper width and height can be set only when the in-line element is transformed into a block level element

span {
    
        width: 200px;
        height: 200px;
      }

Display conversion ：

display: block;
display: inline-block;

A transformation of hermits :

float： （left and right）
position：（absolute and fixed）

Of course, the above are commonly used, not only these ,display There are many values of , Many of them can convert inline elements into block level elements