How to prevent column break within an element?

Question

Consider the following HTML:

    

        
Number one
        
Number two
        &         


        
      

Answer 1

The accepted answer is now two years old and things appear to have changed.

This article explains the use of the column-break-inside property. I can't say how or why this differs from break-inside, because only the latter appears to be documented in the W3 spec. However, the Chrome and Firefox support the following:

li {
    -webkit-column-break-inside:avoid;
       -moz-column-break-inside:avoid;
            column-break-inside:avoid;
}