:left is a CSS pseudo-class selector used to select all the left pages of a printed document. 75o28

When printing double-sided documents (such as books), the pages on left and right pages may be different. The :left page selector is used in conjunction with the @page, :left acts kind of like a filter used to select only the left pages.

@page :left {
    /* styles for the left pages */
}
                

In addition to :left, a :right, which select the first page and all the right pages in double-sided documents, respectively.

Styles specified in a :left @page rule that has no pseudo-class specified.

Styles specified in a @page rules.

It is important to note that you cannot change all CSS properties inside an @rule. See the @page entry for more information on what styles can be changed and/or applied.

All pages are automatically classified by agents into either the :left or page break before the first generated box.

If a forced break occurs before the first generated box, it is undefined in CSS 2.1 whether :first applies to the blank page before the break or to the page after it.

If different declarations have been given for left and right pages, the agent must honor these declarations even if the agent does not transfer the pages to left and right sheets (e.g., a printer that only prints single-sided).

@page :left {
    /* styles for the left pages go here... */
}
                

/* All margins set to 2cm */
@page { 
    margin: 2cm; 
} 

/* Left margin on left pages 2.5cm */
@page :left {
  margin-left: 2.5;    
}