jQuery carousel making responsive

Question

I have this carousel which is not responsive and need to make it responsive but not sure what to do with it as its a current carousel ive found online that ive been using.

Can someone maybe help me get it responsive? they are just going to be images - many thanks in advance

http://codepen.io/anon/pen/RNPYqq

HTML:

<div id="slider">
  <a href="#" class="control_next">></a>
  <a href="#" class="control_prev"><</a>
  <ul>
    <li><img src="http://placehold.it/1130x775"></li>
    <li><img src="http://placehold.it/1130x775"></li>
    <li><img src="http://placehold.it/1130x775"></li>
    <li><img src="http://placehold.it/1130x775"></li>
  </ul>  
</div>

JS:

jQuery(document).ready(function ($) {

    setInterval(function () {
        moveRight();
    }, 3000);

    var slideCount = $('#slider ul li').length;
    var slideWidth = $('#slider ul li').width();
    var slideHeight = $('#slider ul li').height();
    var sliderUlWidth = slideCount * slideWidth;

    $('#slider').css({ width: slideWidth, height: slideHeight });

    $('#slider ul').css({ width: sliderUlWidth, marginLeft: - slideWidth });

    $('#slider ul li:last-child').prependTo('#slider ul');

    function moveLeft() {
        $('#slider ul').animate({
            left: + slideWidth
        }, 200, function () {
            $('#slider ul li:last-child').prependTo('#slider ul');
            $('#slider ul').css('left', '');
        });
    };

    function moveRight() {
        $('#slider ul').animate({
            left: - slideWidth
        }, 200, function () {
            $('#slider ul li:first-child').appendTo('#slider ul');
            $('#slider ul').css('left', '');
        });
    };

    $('a.control_prev').click(function () {
        moveLeft();
    });

    $('a.control_next').click(function () {
        moveRight();
    });

});    

CSS:

@import url(http://fonts.googleapis.com/css?family=Open+Sans:400,300,600);  

html {
  border-top: 5px solid #fff;
  background: #58DDAF;
  color: #2a2a2a;
}

html, body {
  margin: 0;
  padding: 0;
  font-family: 'Open Sans';
}

h1 {
  color: #fff;
  text-align: center;
  font-weight: 300;
}

#slider {
  position: relative;
  overflow: hidden;
  margin: 20px auto 0 auto;
  border-radius: 4px;
}

#slider ul {
  position: relative;
  margin: 0;
  padding: 0;
  height: 200px;
  list-style: none;
}

#slider ul li {
  position: relative;
  display: block;
  float: left;
  margin: 0;
  padding: 0;
  width: 1130px;
  height: 775px;
  background: #ccc;
  text-align: center;
  line-height: 300px;
}

a.control_prev, a.control_next {
  position: absolute;
  top: 40%;
  z-index: 999;
  display: block;
  padding: 4% 3%;
  width: auto;
  height: auto;
  background: #2a2a2a;
  color: #fff;
  text-decoration: none;
  font-weight: 600;
  font-size: 18px;
  opacity: 0.8;
  cursor: pointer;
}

a.control_prev:hover, a.control_next:hover {
  opacity: 1;
  -webkit-transition: all 0.2s ease;
}

a.control_prev {
  border-radius: 0 2px 2px 0;
}

a.control_next {
  right: 0;
  border-radius: 2px 0 0 2px;
}

.slider_option {
  position: relative;
  margin: 10px auto;
  width: 160px;
  font-size: 18px;
}

UPDATE: I have made the CSS 100% in width and height with aut but the JS now needs work i think and dont know what to do here as it sets the ontainer height and width margin stuff to move etc... can someone help me with this please?

Answer 1

You can calculate the li's width using the document's width and the width of the ul will be taken care of.

JS

    //get width of document here and set to li
    $('#slider ul li').css({"width":($(document).width()-200)});

    var slideCount = $('#slider ul li').length;
    var slideWidth = $('#slider ul li').width();
    var slideHeight = $('#slider ul li').height();
    var sliderUlWidth = slideCount * slideWidth;

    $('#slider').css({ width: slideWidth, height: slideHeight });


    $('#slider ul').css({ width: sliderUlWidth, marginLeft: - slideWidth });

CSS

#slider ul li { 

    /* other CSS */

    height: 100%;

  }

And for the image to be responsive with respect to the parent

#slider ul li img { 
 max-width: 100%;
 max-height: 100%;
}

Demo

On Window resize Updated Fiddle