.container-fluid, .row {
  margin: 0;
  padding: 0;
}

.arrow_down, .arrow_top {
  position: relative;
}

.arrow_down:before {
  position: absolute;
  width: 49%;
  left: 0;
  bottom: 0;
  border-bottom: 20px solid white;
  border-right: 20px solid transparent;
  display: block;
  content: " ";
}

.arrow_down:after {
  position: absolute;
  left: 49%;
  bottom: 0;
  right: 0;
  border-bottom: 20px solid white;
  border-left: 20px solid transparent;
  display: block;
  content: " ";
}

.arrow_top:before {
  position: absolute;
  width: 49%;
  left: 0;
  top: 0;
  border-top: 20px solid white;
  border-right: 20px solid transparent;
  display: block;
  content: " ";
}

.arrow_top:after {
  position: absolute;
  left: 49%;
  top: 0;
  right: 0;
  border-top: 20px solid white;
  border-left: 20px solid transparent;
  display: block;
  content: " ";
}