*{
  /*border: 1px solid blue;*/
}
body{
  margin: 0;
  padding: 0;
}
/****************   PARALLAX STYLE    ***************/

.slide {
  position: relative;
  padding: 25vh 10%;
  min-height: 100vh;
  width: 100vw;
  box-sizing: border-box;
  box-shadow: 0 -1px 10px rgba(0, 0, 0, .7);
  transform-style: inherit;
}
.slide:before {
  content: "";
  position: absolute;
  top: 0;
  bottom: 0;
  left:0;
  right:0;
}
.slide:nth-child(2n) .title {
  margin-left: 0;
  margin-right: auto;
}

.slide:nth-child(2n+1) .title {
  margin-left: auto;
  margin-right: 0;
}
.slide, .slide:before {
  background: 50% 50% / cover;
}
#header {
  background: url('../images/nuclear.jpg') no-repeat;
  background-size: cover;
  background-attachment: fixed;
}
#slide-1{
  background: url('../images/plain-background.jpg') no-repeat;
  background-size: cover;
  background-attachment: fixed;
}
#slide-2{
  background: white;
  background-size: cover;
  background-attachment: fixed;
}
#slide-3{
  background: url('../images/Sedan_Plowshare_Crater.jpg') no-repeat 100% 55%;
  background-size: cover;
  background-attachment: fixed;
}

/******************   HEADER     *****************/
header{
  min-height: 700px;
  color: white;
}
header h1{
  margin: 0;
  padding: 15px;
  padding-top: 12%;
}
header a{
  color: white;
  text-decoration: none;
}
.header-info{
  background: white;
  color: black;
  opacity: 0.8;
  padding: 15px;
}
.header-container{
  margin: auto;
}
.header-up-text{
  /*position: relative;*/
}
.header-down-text{
  float: right;
  padding-top: 20%;
}
.play-demo a{
  display: none;
  background: white;
  color: navy;
  padding: 20px;
  text-align: center;
  margin: auto;
  width: 50%;
  margin-top: 7%;
}

/********   navigation bar     ********/
.nav-bar{
  float: right;
  text-align: right;
  margin-top: 20px;
}
.nav-bar:after{
  content: '';
  display: table;
  clear: both;
}
.nav-bar li{
  display: inline-block;
  padding: 20px 15px;
}
.nav-bar .active{
  border-top: 2px solid white;
}
.nav-bar li:hover{
  border-top: 2px solid white;
}
.header-hidden-menu{
  display: none;
}
/******************   MAIN     *****************/

/******************   FOOTER     *****************/
/******************   MOBILE     *****************/
@media ( max-width : 400px ){
  .nav-bar{
    width: 100%;
    text-align: left;
    display: none;
  }
  .nav-bar li{
    display: block;
    width: 100%;
  }
/*  .header-hidden-menu{
    display: block;
    float: right;
    margin-right: 5%;
  }
  .header-hidden-menu i{
    color: white;
    width: 20px;
    height: 20px;
  }*/
  .play-demo a{
    display: block;
  }
}