footer {
  background-color: rgba(255, 255, 255, 0);
  color: gray;
  clear: both;
  text-align: center;
  padding: 5px;
}

/* The Magic Float Center Code */
.float_center {
  float: right;

  position: relative;
  left: -50%; /* or right 50% */
  /*text-align: left;*/
  /*background-color: blue;*/
}
.float_center > .child {
  position: relative;
  left: 50%;
  /*background-color: yellow;*/
}
.hidden {
  display:none;
  /*height: 0px;*/
}



/* style */
body {
  height: auto;
  width: auto;
  background-image: url("../res/images/creases.png");
  background-repeat: no-repeat;/*repeat-x;*/
  background-size: cover;
  /*background-position: top;*/
  background-attachment: fixed;
  background-color: black;
  font-family: sans-serif;
}
.text_right {
  text-align: right;
}
.text_center {
  text-align: center;
}
.clear {
  clear:both;
}
.preview {
  width: 300px;
  display: block;
  margin: auto;
}

#big_space {
  padding: 50px;
}
#small_space {
  padding: 20px;
}
#container {
  width: 50%;
  min-width: 400px;
  margin: 0 auto 0 auto;
  padding: 20px;
}
#summary {
  clear: both;
  background-color: rgba(255, 255, 255, 0.8);
  border-radius: 10px;
  overflow-y: auto;
}
a {
  text-decoration: none;
  color: black;
  /*color: rgba(70, 70, 70, 255);*/
}
#page {
    display: none;
}
#loading {
    display: block;
    position: absolute;
    top: 0;
    left: 0;
    z-index: 100;
    width: 100vw;
    height: 100vh;
    background-color: rgba(192, 192, 192, 0.5);
    background-image: url("http://i.stack.imgur.com/MnyxU.gif");
    background-repeat: no-repeat;
    background-position: center;
}