CSS set li indent

to indent a ul dropdown menu, use

/* Main Level */
ul{
  margin-left:10px;
}

/* Second Level */
ul ul{
  margin-left:15px;
}

/* Third Level */
ul ul ul{
  margin-left:20px;
}

/* and so on... */

You can indent the lis and (if applicable) the as (or whatever content elements you have) as well , each with differing effects. You could also use padding-left instead of margin-left, again depending on the effect you want.

Update

By default, many browsers use padding-left to set the initial indentation. If you want to get rid of that, set padding-left: 0px;

Still, both margin-left and padding-left settings impact the indentation of lists in different ways. Specifically: margin-left impacts the indentation on the outside of the element’s border, whereas padding-left affects the spacing on the inside of the element’s border. (Learn more about the CSS box model here)

Setting padding-left: 0; leaves the li’s bullet icons hanging over the edge of the element’s border (at least in Chrome), which may or may not be what you want.

Examples of padding-left vs margin-left and how they can work together on ul: https://jsfiddle.net/daCrosby/bb7kj8cr/1/