Slider responsive in div-container (css)

Hi there,

i want to make the slider responsive and placed it in a div container with css class “slider”:

<div class="slider">
[easingslider id="91"]</div>

The “slider class” has following code:

.slider{
padding : 5px;
padding-right : 10px;
clear : none;
float : left;
position : relative;
max-width : 500px;
max-height : 300px;
}

In Slider options i activated the “responsive mode” where is said:

Check this option to make this slider responsive. If enabled, the “width” and “height” values above will act as maximums.

I hoped, that this will work and the slider will be responsive with the div container around it.
But the slider and the container are always 1px in height and 1px in width on the page.

Does someone has an idea how to make the slider really responsive in a div container?

Thank you

https://ww.wp.xz.cn/plugins/easing-slider/