:root {
  --site-header-top-offset: 16px;
  --site-header-width: min(1220px, calc(100% - 112px));
}

site-header {
  display: block;
  position: relative;
  z-index: 50;
}

.site-header {
  position: fixed;
  top: var(--site-header-top-offset);
  left: 50%;
  z-index: 40;
  width: var(--site-header-width);
  transform: translateX(-50%);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  padding: 12px 16px;
  border: 1px solid rgba(215, 228, 250, 0.22);
  border-radius: 24px;
  background: rgba(255, 255, 255, 0.86);
  backdrop-filter: blur(18px);
  -webkit-backdrop-filter: blur(18px);
  box-shadow: 0 16px 38px rgba(16, 51, 95, 0.10);
}

.brand {
  display: flex;
  align-items: flex-end;
  gap: 0;
  color: #1a1a1a;
  text-decoration: none;
}

.brand-logo {
  display: flex;
  flex: 0 0 auto;
  align-items: center;
}

.brand-logo img {
  display: block;
  width: clamp(112px, 11vw, 144px);
  height: auto;
  object-fit: contain;
}

.site-nav {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 28px;
  margin-left: auto;
  margin-right: 44px;
}

.site-header__menu-toggle {
  display: none;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  padding: 0;
  border: 1px solid rgba(0, 94, 173, 0.16);
  border-radius: 14px;
  background: rgba(255, 255, 255, 0.82);
  color: #005ead;
  box-shadow: 0 10px 24px rgba(0, 94, 173, 0.08);
  transition: background-color 180ms ease, border-color 180ms ease, transform 180ms ease;
}

.site-header__menu-toggle:hover {
  transform: translateY(-1px);
  border-color: rgba(0, 94, 173, 0.28);
  background: rgba(255, 255, 255, 0.94);
}

.site-header__menu-toggle .material-symbols-outlined {
  font-size: 22px;
  line-height: 1;
}

.site-nav a {
  color: #1a1a1a;
  display: inline-flex;
  align-items: center;
  gap: 4px;
  font-family: "IBM Plex Sans JP", "Hiragino Sans", "Yu Gothic", sans-serif;
  font-size: 0.98rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: none;
  white-space: nowrap;
  transition: color 180ms ease;
}

.site-nav a:hover,
.site-nav a[aria-current="page"] {
  color: #005ead;
}

.site-nav-icon {
  font-size: 16px;
  line-height: 1;
}

@media (max-width: 767px) {
  :root {
    --site-header-top-offset: 12px;
    --site-header-width: min(1220px, calc(100% - 24px));
  }

  .site-header {
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 14px;
    width: min(1220px, calc(100% - 24px));
    padding: 12px 14px;
    border-radius: 20px;
  }

  .brand {
    gap: 0;
  }

  .brand-logo img {
    width: min(132px, 36vw);
  }

  .site-header__menu-toggle {
    display: inline-flex;
    margin-left: auto;
  }

  .site-nav {
    display: none;
    position: static;
    width: 100%;
    flex-direction: column;
    align-items: stretch;
    gap: 8px;
    padding-top: 6px;
    border-top: 1px solid rgba(0, 94, 173, 0.1);
    margin-left: 0;
    margin-right: 0;
  }

  .site-header[data-menu-state="open"] .site-nav {
    display: flex;
  }

  .site-nav a {
    justify-content: space-between;
    gap: 12px;
    padding: 12px 14px;
    border-radius: 14px;
    background: rgba(244, 247, 255, 0.92);
    font-size: 0.9rem;
  }
}