.jumbotron {
  padding-top: 3rem;
  padding-bottom: 3rem;
  margin-bottom: 0;
  background-color: #fff;
}
@media (min-width: 768px) {
  .jumbotron {
    padding-top: 6rem;
    padding-bottom: 6rem;
  }
}

.jumbotron p:last-child {
  margin-bottom: 0;
}

.jumbotron-heading {
  font-weight: 300;
}

.jumbotron .container {
  max-width: 40rem;
}

footer {
  padding-top: 3rem;
  padding-bottom: 3rem;
}

footer p {
  margin-bottom: .25rem;
}

.gradient_bg {
  background-image: -webkit-gradient(linear, right top, left top, from(#0197e7), to(#9bdcff));
  background-image: linear-gradient(to left, #0197e7 0%, #9bdcff 100%);
}

/* Fallback styles */
.book {
  display: inline-block;
  -webkit-box-shadow: 5px 5px 20px #333;
          box-shadow: 5px 5px 20px #333;
  margin: 10px;
}

.book img { vertical-align: middle; }

/*
 *  In order for this to work, you must use Modernizer
 *  to detect 3D transform browser support. This will add
 *  a "csstransforms3d" class to the HTML element.
 *
 *  Visit http://modernizr.com/ for installation instructions
 */

.csstransforms3d  .books {
  -moz-perspective: 100px;
  -moz-transform-style: preserve-3d;
  -webkit-transform-style: preserve-3d;
}

.csstransforms3d  .book {
  position: relative;
  -moz-perspective: 100px;
  -moz-transform: rotateY(-3deg);
  -webkit-transform: perspective(100) rotateY(-3deg);
  outline: 1px solid transparent; /* Helps smooth jagged edges in Firefox */
  -webkit-box-shadow: none;
          box-shadow: none;
  margin: 0;
}

.csstransforms3d  .book img {
  position: relative;
  max-width: 100%;
}

.csstransforms3d  .book:before,
.csstransforms3d  .book:after {
  position: absolute;
  top: 2%;
  height: 96%;
  content: ' ';
  z-index: -1;
}

.csstransforms3d  .book:before {
  width: 100%;
  left: 7.5%;
  background-color: #254053;;
  -webkit-box-shadow: 5px 5px 20px #333;;
          box-shadow: 5px 5px 20px #333;
}

.csstransforms3d  .book:after {
  width: 5%;
  left: 100%;
  background-color: #EFEFEF;
  -webkit-box-shadow: inset 0px 0px 5px #aaa;
          box-shadow: inset 0px 0px 5px #aaa;
  -moz-transform: rotateY(20deg);
  -webkit-transform: perspective(100) rotateY(20deg);
}

/* RIBBONS */ 
.ribbon {
   position: absolute;
   right: -5px; top: -5px;
   z-index: 1;
   overflow: hidden;
   width: 75px; height: 75px; 
   text-align: right;
}
.ribbon span {
   font-size: 10px;
   color: #fff; 
   text-transform: uppercase; 
   text-align: center;
   font-weight: bold; line-height: 20px;
   -webkit-transform: rotate(45deg);
           transform: rotate(45deg);
   width: 100px; display: block;
   background: #79A70A;
   background: -webkit-gradient(linear, left top, left bottom, from(#9BC90D), to(#79A70A));
   background: linear-gradient(#9BC90D 0%, #79A70A 100%);
   -webkit-box-shadow: 0 3px 10px -5px rgba(0, 0, 0, 1);
           box-shadow: 0 3px 10px -5px rgba(0, 0, 0, 1);
   position: absolute;
   top: 19px; right: -21px;
}
.ribbon span::before {
   content: '';
   position: absolute; 
   left: 0px; top: 100%;
   z-index: -1;
   border-left: 3px solid #79A70A;
   border-right: 3px solid transparent;
   border-bottom: 3px solid transparent;
   border-top: 3px solid #79A70A;
}
.ribbon span::after {
   content: '';
   position: absolute; 
   right: 0%; top: 100%;
   z-index: -1;
   border-right: 3px solid #79A70A;
   border-left: 3px solid transparent;
   border-bottom: 3px solid transparent;
   border-top: 3px solid #79A70A;
}
.red span {background: -webkit-gradient(linear, left top, left bottom, from(#F70505), to(#8F0808));background: linear-gradient(#F70505 0%, #8F0808 100%);}
.red span::before {border-left-color: #8F0808; border-top-color: #8F0808;}
.red span::after {border-right-color: #8F0808; border-top-color: #8F0808;}

.blue span {background: -webkit-gradient(linear, left top, left bottom, from(#2989d8), to(#1e5799));background: linear-gradient(#2989d8 0%, #1e5799 100%);}
.blue span::before {border-left-color: #1e5799; border-top-color: #1e5799;}
.blue span::after {border-right-color: #1e5799; border-top-color: #1e5799;}