The lines in the "hamburger" menu don't have a default colour set.
You could add either the
navbar-default
or
navbar-inverse
class to your
navbar
. However, this would also set the background and border colour for the
navbar
itself, meaning that your image wouldn't show through.
Alternatively, you could set a default background colour for the icon bar:
.navbar .navbar-toggle .icon-bar
{
background-color: #888;
}
There will be other styles from
navbar-default
which you might need to copy, depending on how you want the navbar to look.
To get the background image to scale, you'll need to use
the background-size
property[
^] - set it to either
contain
or
cover
, depending on how you want the image to scale.
NB: This property is
not supported in IE8 or earlier[
^].
Example:
https://jsfiddle.net/6pvzdgut/[
^]