Why in collapsible widget between items, in header (double line with empty black color) and footer there is empty space like image attached... ? In footer one item is also Not aligned with other footer buttons... well?

1.      < link rel= "shortcut icon" href= "../favicon.ico" >

   < link rel= "stylesheet" href= "http://fonts.googleapis.com/css?family=Open+Sans:300,400,700" >

        < link rel= "stylesheet" href= "../css/themes/default/jquery.mobile-1.4.5.min.css" >

        < link rel= "stylesheet" href= "../_assets/css/jqm-demos.css" >

        < script src= "../js/jquery.js" > < / script >

        < script src= "../_assets/js/index.js" > < / script >
       <script src="../js/jquery.mobile-1.4.5.min.js"></script>
2. <!-- page : demo-page home - start -->
3.      < div data-role= "page" id= "demo-page" data-url= "demo-page" >

            < div data-role= "header" data-theme= "b" >

                < h1 >Design Patterns GoF &amp; more in 4 Languages </ h1 >

                < a href= "#left-panel" data-icon= "carat-r" data-iconpos= "notext" data-shadow= "false" data-iconshadow= "false" class= "ui-nodisc-icon" >Open left panel </ a >

                < a href= "#right-panel" data-icon= "carat-l" data-iconpos= "notext" data-shadow= "false" data-iconshadow= "false" class= "ui-nodisc-icon" >Open right panel </ a >

            </ div > <!-- /header -->

            < div role= "main" class= "ui-content" >

   
   

                < div data-role= "collapsible" data-inset= "true" >

                    < h3 >Creational (5) </ h3 >

                    < ul data-role= "listview" >

                        < li >< a href= "#pattern" data-dp= "Singleton" >Singleton </ a ></ li >

                        < li >< a href= "#pattern" data-dp= "Prototype" >Prototype </ a ></ li >

                        < li >< a href= "#pattern" data-dp= "FactoryMethod" >Factory Method </ a ></ li >

                        < li >< a href= "#pattern" data-dp= "AbstractFactory" >Abstract Factory </ a ></ li >

                        < li >< a href= "#pattern" data-dp= "Builder" >Builder </ a ></ li >

                    </ ul >