.contenedor{
  background:#fff;
  max-width: 75%;
  height: auto;
  margin: 0 auto;
}
.menu_bar{
  display: none;
}
nav ul {
  padding: 0;
  font-size: 0;
  list-style: none;
  width: 85%;
  margin: auto;

}

nav ul li {
  box-sizing: border-box;
  display: inline-block;
  vertical-align: top;
  font-size: 13px;
  padding:10px;
  width: 14%;
  height: auto;
  text-align: center;

}


nav ul li a{
  color: #000;
  text-align: center;
  text-transform: uppercase;
  text-decoration: none;

}


nav ul li ul {
  display: none;
  position: absolute;
  background: red;
  max-width: 240px;

}

nav ul li:hover ul{
  display: block;
}

nav ul li ul li{
  display: block;
  position: relative;
  padding: 10px;
  height: 60px;
  width: 100%;
}
nav ul li ul li a{
  font-size: 15px;
}


@media screen and (max-width:767px ) {
   nav {
    position: fixed;
    width:90%;
    height:100%;
    left:-100%;
    margin:0;
    top: -85px;
    z-index: 1000;
  }

  nav ul {
    background: #fff;
  }

   nav ul li {
    display:block;
    float:none;
    border-bottom:1px solid #000;
    width: 100%;
    text-align: left;
    height: auto;
    padding: 10px;
  }

  .menu_bar {
    display:block;
    width:100%;
    background:#000;
    position: absolute;
    top: 0px;
  }

  .menu_bar .bt-menu {
    display:block;
    padding:5px;
    background:#024959;
    color:#fff;
    text-decoration:none;
    font-weight: bold;
    font-size:30px;
    -webkit-box-sizing:border-box;
    -moz-box-sizing:border-box;
    box-sizing:border-box;
    text-align:right;
  }

  .menu_bar span {
    float:right;
    font-size:40px;
  }

  header{
    height:95px;
  }

}