/* ===============================================================
   Layout / Container / Header / Sections / Footer / Nav Responsive
=============================================================== */

.container {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 clamp(16px, 2.5vw, 30px);
}

/* =========================
   Header
========================= */
.site-header {
  background-color: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(12px);
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.08);
  padding-top: 10px;
  padding-bottom: 10px;
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  width: 100%;
}

.site-header .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
}

.logo img {
  height: 50px;
}

.logo span {
  font-size: 24px;
  font-weight: 700;
  color: var(--primary-color);
}

.main-nav {
  display: flex;
  gap: 25px;
  align-items: center;
}

/* Default: hidden on desktop (shown via media query at <=1024px) */
.mobile-menu-toggle {
  display: none;
}

.main-nav a {
  font-weight: 600;
  font-size: 17px;
  position: relative;
  padding: 8px 0;
  color: var(--text-color);
  text-decoration: none;
  transition: color 0.3s ease;
}

.main-nav a::after {
  content: '';
  position: absolute;
  bottom: -5px;
  left: 0;
  width: 0;
  height: 2px;
  background-color: var(--primary-color);
  transition: width var(--transition-speed) ease;
}

.main-nav a:hover::after {
  width: 100%;
}

.main-nav a:hover {
  color: var(--primary-color);
}

/* =========================
   Sections (共通)
========================= */
.site-section {
  padding: 100px 0;
  position: relative;
}

.site-section-dark {
  background-color: var(--dark-bg);
  color: var(--text-color-dark);
  padding: 100px 0;
  position: relative;
}

.section-header {
  text-align: center;
  margin-bottom: 60px;
}

.section-header h2 {
  font-size: clamp(30px, 4vw, 36px);
  font-weight: 700;
  margin: 0 0 15px 0;
}

.section-header.dark h2 {
  color: var(--white);
}

.section-header h2::after {
  content: '';
  display: block;
  width: 70px;
  height: 4px;
  background-color: var(--primary-color);
  margin: 10px auto 0;
  border-radius: 2px;
}

/* =========================
   Footer
========================= */
.site-footer {
  background-color: var(--dark-bg);
  color: var(--text-color-light);
  padding: 60px 0;
}

.footer-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 40px;
  margin-bottom: 40px;
}

.footer-column h4 {
  color: var(--white);
  margin-bottom: 15px;
  font-size: 18px;
}

.footer-column ul {
  list-style: none;
  padding: 0;
  margin: 0;
}

.footer-column li {
  margin-bottom: 10px;
}

.footer-column a {
  color: var(--text-color-light);
  text-decoration: none;
  transition: color 0.3s;
}

.footer-column a:hover {
  color: var(--primary-color);
}

.footer-bottom {
  text-align: center;
  border-top: 1px solid var(--dark-bg-light);
  padding-top: 30px;
  font-size: 14px;
}

/* =========================
   Responsive: Nav / Layout
========================= */

/* ハンバーガーメニュー (タブレット & スマートフォン) */
@media (max-width: 1024px) {
  .main-nav {
    flex-direction: column;
    justify-content: center;
    align-items: center;
    background: rgba(255, 255, 255, 0.98);
    backdrop-filter: blur(10px);
    position: fixed;
    top: 0;
    right: 0;
    height: 100%;
    width: 80%;
    max-width: 320px;
    padding-top: 5rem;
    transition: transform 0.3s ease-in-out;
    transform: translateX(100%);
    gap: 30px;
    z-index: 1005;
  }

  .main-nav.is-open {
    transform: translateX(0);
  }

  .main-nav a {
    font-size: 18px;
    font-weight: bold;
  }

  .mobile-menu-toggle {
    display: flex;
    flex-direction: column;
    justify-content: space-around;
    width: 30px;
    height: 25px;
    background: transparent;
    border: none;
    cursor: pointer;
    padding: 0;
    z-index: 1010;
  }

  .mobile-menu-toggle span {
    display: block;
    width: 30px;
    height: 3px;
    background-color: var(--text-color);
    border-radius: 10px;
    transition: all 0.3s ease-in-out;
    transform-origin: center;
  }

  /* Hamburger to X animation */
  .mobile-menu-toggle.is-open span:nth-child(1) {
    transform: translateY(8px) rotate(45deg);
  }

  .mobile-menu-toggle.is-open span:nth-child(2) {
    opacity: 0;
  }

  .mobile-menu-toggle.is-open span:nth-child(3) {
    transform: translateY(-8px) rotate(-45deg);
  }
}

/* タブレット */
@media (min-width: 769px) and (max-width: 1024px) {
  .desktop-nav {
    display: none;
  }

  .site-section,
  .site-section-dark {
    padding: 80px 0;
  }
}

/* スマートフォン */
@media (max-width: 768px) {
  .desktop-nav {
    display: none;
  }

  .site-section,
  .site-section-dark {
    padding: 60px 0;
  }

  .site-header .container {
    flex-direction: column;
  }
}