#hero-national-standard {
  width: 100%;
  height: 28.125vw;
}
@media (min-width: 1920px) {
  #hero-national-standard {
    height: 540px;
  }
}
#hero-national-standard {
  background: url(../../img/products_services/national_standard/banner.jpg) center/cover no-repeat;
}

#section-approving-unit,
#section-teaching-books {
  padding-top: 4.1666666667vw;
  padding-bottom: 3.125vw;
}
@media (min-width: 1920px) {
  #section-approving-unit,
  #section-teaching-books {
    padding-top: 80px;
    padding-bottom: 60px;
  }
}
#section-approving-unit,
#section-teaching-books {
  background: #fff;
}

.ns-slider {
  position: relative;
  margin-top: 2.0833333333vw;
}
@media (min-width: 1920px) {
  .ns-slider {
    margin-top: 40px;
  }
}
.ns-slider .swiper {
  width: 44.2708333333vw;
}
@media (min-width: 1920px) {
  .ns-slider .swiper {
    width: 850px;
  }
}
.ns-slider .swiper {
  margin: 0 auto;
  overflow: hidden;
}
.ns-slider .swiper-slide {
  text-align: center;
}
.ns-slider .swiper-slide img {
  max-width: 100%;
}
.ns-slider .swiper-button-prev,
.ns-slider .swiper-button-next {
  -webkit-user-select: none;
     -moz-user-select: none;
          user-select: none;
}
@media (max-width: 319px) {
  .ns-slider .swiper-button-prev,
  .ns-slider .swiper-button-next {
    display: none;
  }
}
.ns-slider .swiper-button-prev.swiper-button-disabled,
.ns-slider .swiper-button-next.swiper-button-disabled {
  opacity: 0.6;
}
.ns-slider .swiper-button-prev::after,
.ns-slider .swiper-button-next::after {
  font-size: 1.7708333333vw;
}
@media (min-width: 1920px) {
  .ns-slider .swiper-button-prev::after,
  .ns-slider .swiper-button-next::after {
    font-size: 34px;
  }
}
.ns-slider .swiper-button-prev::after,
.ns-slider .swiper-button-next::after {
  color: #e9e9e9;
}
.ns-slider .swiper-button-prev:hover::after,
.ns-slider .swiper-button-next:hover::after {
  color: #007aff;
}
.ns-slider .swiper-button-prev {
  left: 7.8125vw;
}
@media (min-width: 1920px) {
  .ns-slider .swiper-button-prev {
    left: 150px;
  }
}
.ns-slider .swiper-button-next {
  right: 7.8125vw;
}
@media (min-width: 1920px) {
  .ns-slider .swiper-button-next {
    right: 150px;
  }
}