.swiper-container {
  width: 100%;
}
/* 以下、矢印を変更 */
.swiper-button-next::after {
  font-family: "Font Awesome 5 Free";
  font-size: 20px;
  font-weight: 900;
  position: absolute;
  top: 50%;
  right: 10px;
  content: "\f144";
  transform: translateY(-50%);
}