Не работает float left

.slider { 
	width: 770px; 
	height: 305px; 
	overflow: hidden; 
	margin: 0 auto; 
	padding-top: 65px;} 
 
    .slider ul { 
	width: 770px; 
	height: 305px; 
	margin: 0; 
	list-style: none; 
	padding: 0;} 
 
    li.slide { 
	float: left; 
	width: 770px; 
	height: 305px;}

<div class="slider"> 
  <ul> 
    <li class="slide"></li> 
    <li class="slide"></li> 
    <li class="slide"></li> 
    <li class="slide"></li> 
    <li class="slide"></li> 
  </ul> 
</div>