/* =========================
   🔵 서브메뉴 스타일 (PC 기본)
   ========================= */
.submenu {
  display: flex;
  justify-content: center;
  gap: 40px;
  padding-top: 10px;
  padding-bottom:10px;
  border-bottom:3px solid #eee;
  position: relative;
  font-size: 1rem;
  font-weight: 500;
}

.submenu a {
  position: relative;
  text-decoration: none;
  color: #333;
  padding: 8px 0;
  transition: color 0.3s, font-weight 0.3s;
  display: inline-block;
  text-align: center;
}

.submenu a::after {
  content: "";
  position: absolute;
  bottom: -13px;
  left: 0;
  width: 100%;
  height: 3px;
  background-color: #859FB1;
  opacity: 0;
  transition: opacity 0.3s;
  border-radius: 2px;
}

.submenu a.active {
  font-weight: 700;
  color: #000;
}
.submenu a.active::after {
  opacity: 1;
}

.submenu a:hover {
  color: #000;
  font-weight: 600;
}
.submenu a:hover::after {
  opacity: 1;
}


/* =========================
   🔵 파란 배경 제목 영역
   ========================= */
.blue-title {
  background: #859FB1;
  color: white;
  text-align: center;
  padding: 60px 20px;
}

.blue-title h1 {
  font-size: 2.5rem;
  margin-bottom: 10px;
}

.blue-title p {
  font-size: 1rem;
}


/* =========================
   🔵 본문 서브 타이틀
   ========================= */
.sub-title {
  text-align: center;
  font-size: 1.8rem;
  font-weight: 600;
  margin: 60px auto 40px;
  color: #222;
  max-width: 800px;
  line-height: 1.5;
}


/* =========================
   🔵 각 섹션 상단 여백
   ========================= */
.product-intro-section,
.product-diagram,
.benefit-section,
.steps-section {
  margin-top: 40px;
}


/* =========================
   📱 반응형 대응 (768px 이하)
   ========================= */
@media (max-width: 768px) {
  .submenu {
    flex-wrap: wrap;
    gap: 20px;
    justify-content: center;
    padding: 10px 10px;
    font-size: 0.95rem;
  }

  .submenu a {
    font-size: 0.9rem;
    padding: 6px 8px;
    white-space: nowrap;
  }

  .blue-title h1 {
    font-size: 2rem;
  }

  .blue-title p {
    font-size: 0.9rem;
  }

  .sub-title {
    font-size: 1.4rem;
    padding: 0 10px;
  }
}


/* =========================
   📱 더 작은 모바일 대응 (480px 이하)
   ========================= */
@media (max-width: 480px) {
  .submenu {
    gap: 12px;
    font-size: 0.85rem;
  }

  .submenu a {
    font-size: 0.85rem;
    padding: 4px 6px;
  }

  .blue-title h1 {
    font-size: 1.6rem;
  }

  .blue-title p {
    font-size: 0.85rem;
  }

  .sub-title {
    font-size: 1.2rem;
  }
}