css size

height width
Line-height line-height points is composed of three parts, the spacing, text height, the pitch and the vertical pitch equal. So the text is centered.
Once a line height is provided inside the line element must have a high content,
Line-height:. 3; line height is multiplied by the current font size of the current number line is a high value.
display
this attribute specifies the element is displayed in some form,
display: none; the current element is not displayed, do not take up space in the current
Visibility: hidden; hide the current element, but also take up space before.
Display: block; current element is displayed in the form of a block-level, row level elements often transferred block-level elements.
Display: inline; current element displayed in a row-level element, it can often be block-level element-level elements to switch
Display: inline-block; current element displayed in a row-level block, i.e., do not take up a row, width and height can be provided.