.over_post { 
  position:relative;
}

.a20_nav {
  top: -1px;
  z-index: 3;
  opacity: 1;
  cursor:pointer;
  position:absolute;      
  height:508px;
  font-size:32px;
  font-weight:bold;
  display:none;
  color: #FFFFFF;  
}
.a20_nav_bg {
  opacity: 0.5;
  transition: opacity 200ms linear 0s; 
  padding: 0 26px;
  height:482px;
}
.a20_close {
  text-align: right; 
}  
.a20_nav_prev .a20_nav_bg {
  text-align: right;
}
.a20_nav_next .a20_nav_bg {
  text-align: left;  
}
.a20_nav.active .a20_nav_bg {
  opacity: 1;
}

.a01_play {
  font-size: 24px; 
  line-height:24px;
  position:absolute;
  top:50%;
  left:50%;
  color:#FFFFFF;
  margin: -16px 0 0 -17px;
  padding: 3px 7px 3px 9px;
  border-radius: 3px;
  cursor:pointer;  
  background-color:#000000;
  opacity:0.75;  
  width:19px;
  height:26px;
  box-sizing:content-box;
}

.a01_play i {
  opacity:0.9;  
}

/*
* Clearfix
* For clearing floats like a boss h5bp.com/q
*/
.clearfix {
  *zoom: 1;
  &:before,
  &:after {
    display: table;
    content: "";
    /*
    * Fixes Opera/contenteditable bug:
    * http://nicolasgallagher.com/micro-clearfix-hack/#comment-36952
    */
    line-height: 0;
  }
  &:after {
    clear: both;
  }
}

.cf:before,
.cf:after {
    content: " "; /* 1 */
    display: table; /* 2 */
}

.cf:after {
    clear: both;
}

/**
 * For IE 6/7 only
 * Include this rule to trigger hasLayout and contain floats.
 */
.cf {
    *zoom: 1;
}