@media (max-width: 991px){
  .modal-content{
    width: 100%!important;
  }
.header_area .navbar {
      background-image: -moz-linear-gradient( 0deg, rgb(20,29,162) 0%, rgb(255,60,60) 100%);
    background-image: -webkit-linear-gradient( 0deg, rgb(20,29,162) 0%, rgb(255,60,60) 100%);
    background-image: -ms-linear-gradient( 0deg, rgb(20,29,162) 0%, rgb(255,60,60) 100%);

  }}

.tickets_btn {
background-image: -webkit-gradient(linear, left top, right top, from(#FF3C3C), color-stop(51%, #3A48FF ), to(#FF3C3C));
    background-image: -webkit-linear-gradient(left, #FF3C3C  0%, #FF3C3C 51%, #3A48FF 100%);
    background-image: -o-linear-gradient(left, #FF3C3C  0%, #FF3C3C 51%, #3A48FF 100%);
    background-image: linear-gradient(to right, #FF3C3C  0%, #FF3C3C 51%, #3A48FF 100%);
  }
  .flex-center {
  display: -webkit-box;
  display: -ms-flexbox;
  display: flex;
  -webkit-box-align: center;
  -ms-flex-align: center;
  align-items: center;
  -webkit-box-pack: center;
  -ms-flex-pack: center;
  justify-content: center;
}

.preloader {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: #fff;
}
 .wrapper {
   display: flex;
   flex-flow: row wrap;
   justify-content: center;
}
 
.nav-link:hover{
color: grey!important;
  }
 <style>
body {
  font-family: Arial, Helvetica, sans-serif;
}

.flip-card {
  background-color:transparent;
  width:300px;
  height:300px;
  perspective:1000px;
}

.flip-card-inner {
  position:relative;
  width:100%;
  height:100%;
  text-align:center;
  transition:transform 0.6s;
  -webkit-transition:transform 0.6s;
  transform-style:preserve-3d;
  -webkit-transform-style:preserve-3d;
  box-shadow:0 4px 8px 0 rgba(0,0,0,0.2);

}

.flip-card:hover .flip-card-inner {
  transform:rotateY(180deg);
  -webkit-transform:rotateY(180deg);
}

.flip-card-front, .flip-card-back {
  position:absolute;
  width:100%;
  height:100%;
  backface-visibility:hidden;
   -webkit-backface-visibility: hidden;
  -moz-backface-visibility:    hidden;
  -ms-backface-visibility:     hidden;
}

.flip-card-front {
  background-color:#bbb;
  color:black;

}

.flip-card-back {
  background-color:#fff;
  color:#000;
  transform:rotateY(180deg);
  -webkit-transform:rotateY(180deg);
}
      .icon-bar1 {
      
  position: fixed;
  top: 50%;
  -webkit-transform:translateY(-50%);
  -ms-transform:translateY(-50%);
  transform:translateY(-50%);
}

.icon-bar1 a {
  display: block;
  text-align: center;
  padding: 16px;
  transition: all 0.3s ease;
  color: white;
  font-size: 20px;
}
.filterDiv {

  display: none!important; /* Hidden by default */
}

/* The "show" class is added to the filtered elements */
.show {
  display: block!important;
}

.icon-bar1 a:hover {
  color: grey!important;
}