wordpress - move position of menu from right to left/center in twentyfourteen theme

To change side of your menu in main menu from right to left do next thing.
In style.css in this section

 /* Primary Navigation */

        .primary-navigation {
                float: right;
                font-size: 11px;
                margin: 0 1px 0 -12px;
                padding: 0;
                text-transform: uppercase;

or in line 3355(to be specific) change right to left/center  and that is that. In margin section you can change margins of menu position.

Save file and that is it!