* {
  box-sizing: border-box;
}

body {
  position: relative;
  background-color: #e9eef2;
}

#side-bar {
  position: absolute;
  padding: 0;
  margin: 0;
  left: 0;
  width: 30vw;
  border-right: 2px solid #bed1df;
  border-top: 2px solid #bed1df;
  border-bottom: 2px solid #bed1df;
  background-color: #424242;
  transition: left 0.5s;
  height: 100vh;
  z-index: 100;
  overflow-y: scroll;
}

#side-bar.hidden {
  left: -80vw;
}

.level-one {
  position: relative;
  font-family: 'Open Sans', sans-serif;
  text-align: center;
  list-style: none;
  cursor: pointer;
}

.level-one:hover {
  background: #3f8eb9;
  -webkit-box-shadow: inset 1px 1px 10px 1px rgba(0,0,0,0.45);
  -moz-box-shadow: inset 1px 1px 10px 1px rgba(0,0,0,0.45);
  box-shadow: inset 1px 1px 10px 1px rgba(0,0,0,0.45);
}

.level-one a {
  display: block;
  text-decoration: none;
  width: 75%;
  margin: 0 12.5% 0 12.5%;
  border-bottom: 1px solid #bed1df;
}

.level-one a img {
  margin: 10% 12.5% 10% 12.5%;
  width: 66%;
}

.level-one a span {
  color: #bed1df;
  font-size: 0.5em;
  font-weight: bold;
  position: absolute;
  bottom: 2px;
  left: 0;
  right: 0;
}

#side-button {
  position: absolute;
  width: 10vw;
  height: 10vw;
  top: 5vh;
  left:50px;
  text-align: center;
  border: 2px solid #DDD;
  border-radius: 2vw;
  transition: left 0.5s;
  z-index: 100;
  cursor: pointer;
}

#side-button.open {
  left: 35vw;
  background-color: #424242;
}

#side-button .line {
  position: absolute;
  display: block;
  height: 5%;
  background-color: #DDD;
  left: 20%;
  right: 20%;
  transition: transform 0.5s,
              opacity 0.5s;
}

.line-one {
  top: 25%;
}

.line-two {
  top: 50%!important;
}

.line-three {
  top: 75%!important;
}

.line-one.open {
  transform: rotate(45deg) translate(27%, 360%);
}

.line-two.open {
  opacity: 0;
}

.line-three.open {
  transform: rotate(-45deg) translate(27%, -360%);
}

#side-bar-overlay {
  background-color: rgba(0, 0, 0, 0.5);
  width: 100vw;
  height: 100vh;
  position: fixed;
  top: 0;
  left: 0;
  transition: background-color 0.5s;
  z-index: 90;
}

#side-bar-overlay.hidden {
  background-color: rgba(0, 0, 0, 0);
}

@media screen and (min-width: 480px) {
  #side-bar {
    width: 20vw;
  }

  #side-button {
    width: 8vw;
    height: 8vw;
    top: 4vh;
  }

  #side-button.open {
    left: 25vw;
  }
}

@media screen and (min-width: 1025px) {
  #side-button {
    display: none;
  }
}