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

#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: 900px;
  max-height: 600px;
  background: #eee;
  text-align: center;
  line-height: 600px;
}

a.control_prev, a.control_next {
  position: absolute;
  top: 40%;
  z-index: 999;
  display: block;
  padding: 20px;
  width: auto;
  height: auto;
  background:rgba(64,64,64,0.3);
  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;
  background:black;
  transition: all 0.2s ease;
}

a.control_prev {
  border-radius: 4px;
}

a.control_next {
  right: 0;
  border-radius: 4px;
}

.slider_option {
  position: relative;
  margin: 10px auto;
  width: 350px;
  font-size: 18px;
}

#slider img{max-width:900px;}