/* ── Site Nav (共通ヘッダー) ── */
.site-nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 200;
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 48px;
  padding: 0 24px;
  padding-top: env(safe-area-inset-top);
  box-sizing: content-box;
  background: rgba(245,242,236,0.97);
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
  transition: background 400ms var(--ease-snow, cubic-bezier(0.22,0.61,0.36,1)),
              border-color 400ms var(--ease-snow, cubic-bezier(0.22,0.61,0.36,1));
}

.site-nav-logo {
  font-family: var(--font-display, 'Source Serif 4', Georgia, serif);
  font-weight: 500;
  font-size: 17px;
  letter-spacing: 0.08em;
  color: var(--fg, #1E1E1B);
  text-decoration: none;
  flex-shrink: 0;
}

.site-nav-links {
  display: flex;
  align-items: center;
  gap: 20px;
  margin-left: auto;
}

.site-nav-links > a {
  font-family: var(--font-body, 'DM Sans', sans-serif);
  font-size: 13px;
  font-weight: 400;
  color: var(--fg-muted, #5C5850);
  text-decoration: none;
  transition: color 300ms var(--ease-snow, cubic-bezier(0.22,0.61,0.36,1));
}
.site-nav-links > a:hover { color: var(--fg, #1E1E1B); }

.site-nav-divider {
  width: 1px;
  height: 16px;
  background: var(--border, #D6CFC4);
  flex-shrink: 0;
}

/* ── 未ログイン ── */
.site-nav-guest {
  display: flex;
  align-items: center;
  gap: 14px;
}

.site-nav-guest a {
  font-family: var(--font-body, 'DM Sans', sans-serif);
  font-size: 13px;
  font-weight: 400;
  color: var(--fg-muted, #5C5850);
  text-decoration: none;
  transition: color 300ms var(--ease-snow, cubic-bezier(0.22,0.61,0.36,1));
}
.site-nav-guest a:hover { color: var(--fg, #1E1E1B); }

.site-nav-register {
  font-family: var(--font-body, 'DM Sans', sans-serif);
  font-size: 12px;
  font-weight: 500;
  letter-spacing: 0.04em;
  padding: 5px 14px;
  border-radius: var(--radius, 3px);
  background: var(--fg, #1E1E1B);
  color: var(--bg, #F5F2EC) !important;
  text-decoration: none;
  transition: opacity 300ms var(--ease-snow, cubic-bezier(0.22,0.61,0.36,1));
}
.site-nav-register:hover { opacity: 0.85; }

/* ── ログイン済 ── */
.site-nav-user {
  display: none;
  align-items: center;
  gap: 8px;
  text-decoration: none;
  transition: opacity 300ms var(--ease-snow, cubic-bezier(0.22,0.61,0.36,1));
}
.site-nav-user:hover { opacity: 0.8; }

.site-nav-avatar {
  width: 28px;
  height: 28px;
  border-radius: 50%;
  background: var(--neve, #7A9EB0);
  color: white;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-body, 'DM Sans', sans-serif);
  font-size: 12px;
  font-weight: 500;
  overflow: hidden;
  flex-shrink: 0;
}
.site-nav-avatar img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.site-nav-username {
  font-family: var(--font-body, 'DM Sans', sans-serif);
  font-size: 13px;
  font-weight: 400;
  color: var(--fg, #1E1E1B);
}

/* ── ホーム専用: Hero 上で透明 ── */
.site-nav-transparent {
  background: transparent !important;
  border-bottom-color: transparent !important;
  backdrop-filter: none;
}
.site-nav-transparent .site-nav-logo { color: white; }
.site-nav-transparent .site-nav-links > a { color: rgba(255,255,255,0.85); }
.site-nav-transparent .site-nav-links > a:hover { color: white; }
.site-nav-transparent .site-nav-guest a { color: rgba(255,255,255,0.85); }
.site-nav-transparent .site-nav-guest a:hover { color: white; }
.site-nav-transparent .site-nav-register {
  background: transparent;
  border: 1px solid rgba(255,255,255,0.5);
  color: white !important;
}
.site-nav-transparent .site-nav-divider { background: rgba(255,255,255,0.3); }
.site-nav-transparent .site-nav-username { color: white; }
.site-nav-transparent .site-nav-avatar { border: 1px solid rgba(255,255,255,0.3); }

/* ── ハンバーガーボタン（PC では非表示） ── */
.mobile-menu-btn {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
  margin-left: 4px;
}
.mobile-menu-btn span {
  display: block;
  width: 20px;
  height: 2px;
  background: var(--fg, #1E1E1B);
  border-radius: 1px;
  transition: background 300ms;
}
.site-nav-transparent .mobile-menu-btn span { background: white; }

/* ── モバイルメニュー ── */
.mobile-menu {
  display: none;
  position: fixed;
  top: 48px;
  left: 0;
  right: 0;
  background: var(--bg, #F5F2EC);
  border-bottom: 1px solid var(--border, #D6CFC4);
  padding: 8px 20px 16px;
  z-index: 199;
  box-shadow: 0 4px 12px rgba(44,58,66,0.08);
}
.mobile-menu.open { display: block; }
.mobile-menu a {
  display: block;
  padding: 13px 0;
  color: var(--fg, #1E1E1B);
  font-family: var(--font-body, 'DM Sans', sans-serif);
  font-size: 15px;
  border-bottom: 1px solid var(--border, #D6CFC4);
  text-decoration: none;
}
.mobile-menu a:last-child { border-bottom: none; }
.mobile-menu a.mobile-menu-register {
  color: var(--neve, #7A9EB0);
  font-weight: 500;
}
.mobile-menu a.mobile-menu-logout {
  color: var(--fg-muted, #5C5850);
  font-size: 14px;
}
.mobile-menu-user-row {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 13px 0;
  border-bottom: 1px solid var(--border, #D6CFC4);
}
.mobile-menu-avatar {
  width: 28px;
  height: 28px;
  border-radius: 50%;
  background: var(--neve, #7A9EB0);
  color: white;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 12px;
  font-weight: 500;
  overflow: hidden;
  flex-shrink: 0;
}
.mobile-menu-avatar img { width: 100%; height: 100%; object-fit: cover; }
.mobile-menu-username {
  font-family: var(--font-body, 'DM Sans', sans-serif);
  font-size: 14px;
  color: var(--fg, #1E1E1B);
}

/* ── ログイン後ヒーロー行 ── */
.mobile-menu-user-hero {
  display: flex;
  align-items: center;
  gap: 12px;
  background: var(--surface, #EDE8DF);
  margin: -8px -20px 0;
  padding: 16px 20px;
  border-bottom: 1px solid var(--border, #D6CFC4);
  margin-bottom: 4px;
}
.mobile-menu-avatar-lg {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: var(--neve, #7A9EB0);
  color: white;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 16px;
  font-weight: 500;
  overflow: hidden;
  flex-shrink: 0;
}
.mobile-menu-avatar-lg img { width: 100%; height: 100%; object-fit: cover; }
.mobile-menu-username-lg {
  font-family: var(--font-body, 'DM Sans', sans-serif);
  font-size: 15px;
  font-weight: 500;
  color: var(--fg, #1E1E1B);
}

@media (max-width: 768px) {
  .site-nav { padding: 0 16px; }
  .site-nav-links { display: none; }
  .mobile-menu-btn { display: flex; }
}