Hello,
This is Definitely Possible. You can use the Responsive Heights Functionality to increase/decrease the Height of your Slider based on the Screen Size. Make sure that you first remove the .full-screen Class from the #slider Element. Then use the Responsive Heights Functionality as follows:
data-height-lg – Height for Large Devices >=1200px
data-height-md – Height for Medium Devices >=992px to 1199px
data-height-sm – Height for Tablets
data-height-xs – Height for Landscape Mobiles or Phablets.
data-height-xxs – Height for Portrait Mobiles
Example:
<section id="slider" class="slider-parallax swiper_wrapper clearfix" data-height-lg="1000" data-height-md="900" data-height-sm="800" data-height-xs="700" data-height-xxs="600">
....
</section>
This will surely work fine. Let us know if we can help you with anything else or if you find any issues.