.main-header {
  background: linear-gradient(135deg, #a3d5ec, #d9f3fb);
  font-family: "Yu Gothic", "Noto Sans JP", sans-serif;
}

.title-sub {
  letter-spacing: 0.08em;
}
.title-main {
  letter-spacing: 0.1em;
}
.nav-sub {
  font-size: 0.75rem;
}

/* 下線アニメ */
.nav-link-custom::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  width: 100%;
  height: 1px;
  background: rgba(255, 255, 255, 0.5);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.3s;
}
.nav-link-custom:hover::after {
  transform: scaleX(1);
}