My image does not work. I tried to change url to hexadecimal color and it does not show up too. I think I did something wrong with html, but I completely don't know what. Could someone explain me what's wrong?
#showcase {
background: url('http://placekitten.com/300/300') no-repeat center center/cover;
height: 600px;
}<header><nav id="navbar"><h1 class="logo"><a href="#">HBT</a></h1><ul><li><a class="current" href="index.html">Home</a></li><li><a href="about.html">About</a></li><li><a href="contact.html">Contact</a></li></ul></nav><div id="showcase"><div class="container"><div class="showcase-content"><h1><span class="text-primary">Enjoy</span> Your Stay</h1><p class="lead">
Lorem ipsum dolor sit amet, consectetur adipisicing elit. Preferendis aliquam vitae luadantium eligendi accusamus illo?</p><a class="btn" href="about.html">About Our Hotel</a></div></div></div></header>